A longitudinal study of the occupational aspirations and perceptions of nine to twelve year-old South African children
- Authors: Crause, Ewald
- Date: 2006
- Subjects: Vocational interests -- Research -- South Africa , Children -- South Africa -- Attitudes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9843 , http://hdl.handle.net/10948/404 , Vocational interests -- Research -- South Africa , Children -- South Africa -- Attitudes
- Description: Despite the acknowledgement of the developmental nature of careers, little attention has been focused on identifying shaping influences during childhood. This noticeable deficiency in the literature marked the start of the current longitudinal study which was designed to provide information on the career development of nine to twelve-year old South African children. In South Africa research focusing on preadolescent career development is limited with existing research indicating the need to further explore how children’s career choice process initially develops. The study aimed to explore and describe the changes that occur, if any, over a four-year period in terms of occupational interest typology, occupational status levels, occupational gender stereotypes and occupational gender traditionality. Both developmental and career developmental theories were used to provide a context for exploring this process of preadolescent career development. It was decided that quantitative research methods would provide the necessary structure needed to conduct the research. Although semistructured interviews and biographical questionnaires were used to record the verbal data, the data obtained was transposed into nominal data for analysis. Participants responded to questions within a semi-structured interview that focused on four broad areas of questioning. These questions explored participants’ occupational aspirations, how many occupations they knew about, how much they knew about the identified occupation, and the extent to which they held gender-role stereotypes about certain occupations. After the data was iv Key words: career development, children, longitudinal research, occupational aspirations captured it was coded according to Holland's (1985) classification system of occupational interest types. The occupational aspirations expressed by the participants were also coded in terms of their status levels. The coded data was then further analysed using descriptive statistics in the form of frequency counts and percentages. Results from the study support both child and career development theory which view childhood as a time of rapid growth with critical development in various competency areas (including occupational aspirations and perceptions). Although the current study found that most children aspired to Social occupations, the popularity of this typology decreased with increasing age as more children aspired to Investigative, Artistic, and to a lesser extent, Realistic typologies at age twelve. Furthermore, it appears that children, like adults, are aware of status differentials among occupations and that this awareness subsequently influences occupational aspirations. Lastly, the findings broadly provide support for both national and international research in that it was established that an increase in age reflects a decrease in gender-stereotypical perceptions of occupations. The present study gained valuable insight into how the process of career development occurs in preadolescent children. It is clear that there exists a need for the implementation of credible and sustainable career education programs in schools across South Africa in order to encourage and facilitate career exploration during the developmental stage of childhood.
- Full Text:
- Date Issued: 2006
- Authors: Crause, Ewald
- Date: 2006
- Subjects: Vocational interests -- Research -- South Africa , Children -- South Africa -- Attitudes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9843 , http://hdl.handle.net/10948/404 , Vocational interests -- Research -- South Africa , Children -- South Africa -- Attitudes
- Description: Despite the acknowledgement of the developmental nature of careers, little attention has been focused on identifying shaping influences during childhood. This noticeable deficiency in the literature marked the start of the current longitudinal study which was designed to provide information on the career development of nine to twelve-year old South African children. In South Africa research focusing on preadolescent career development is limited with existing research indicating the need to further explore how children’s career choice process initially develops. The study aimed to explore and describe the changes that occur, if any, over a four-year period in terms of occupational interest typology, occupational status levels, occupational gender stereotypes and occupational gender traditionality. Both developmental and career developmental theories were used to provide a context for exploring this process of preadolescent career development. It was decided that quantitative research methods would provide the necessary structure needed to conduct the research. Although semistructured interviews and biographical questionnaires were used to record the verbal data, the data obtained was transposed into nominal data for analysis. Participants responded to questions within a semi-structured interview that focused on four broad areas of questioning. These questions explored participants’ occupational aspirations, how many occupations they knew about, how much they knew about the identified occupation, and the extent to which they held gender-role stereotypes about certain occupations. After the data was iv Key words: career development, children, longitudinal research, occupational aspirations captured it was coded according to Holland's (1985) classification system of occupational interest types. The occupational aspirations expressed by the participants were also coded in terms of their status levels. The coded data was then further analysed using descriptive statistics in the form of frequency counts and percentages. Results from the study support both child and career development theory which view childhood as a time of rapid growth with critical development in various competency areas (including occupational aspirations and perceptions). Although the current study found that most children aspired to Social occupations, the popularity of this typology decreased with increasing age as more children aspired to Investigative, Artistic, and to a lesser extent, Realistic typologies at age twelve. Furthermore, it appears that children, like adults, are aware of status differentials among occupations and that this awareness subsequently influences occupational aspirations. Lastly, the findings broadly provide support for both national and international research in that it was established that an increase in age reflects a decrease in gender-stereotypical perceptions of occupations. The present study gained valuable insight into how the process of career development occurs in preadolescent children. It is clear that there exists a need for the implementation of credible and sustainable career education programs in schools across South Africa in order to encourage and facilitate career exploration during the developmental stage of childhood.
- Full Text:
- Date Issued: 2006
The impact of load and frequency on the biomechanical, physiological and perceptual responses to dynamic pushing
- Authors: Cripwell, Adam Michael
- Date: 2007
- Subjects: Work -- Physiological aspects , Psychophysiology , Human engineering , Biomechanics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5144 , http://hdl.handle.net/10962/d1008183 , Work -- Physiological aspects , Psychophysiology , Human engineering , Biomechanics
- Description: The objective of the present research was to establish the biomechanical, physiological and perceptual responses of male operators to dynamic pushing tasks. The pushing tasks were performed using an industrial pallet jack with varying load/frequency combinations, in a controlled laboratory environment. Thirty healthy male subjects comprised the sample. Experimental procedures were conducted utilising the Chatillon ™ Dynamometer to measure force output in the initial, sustained and ending phases. The K4b2 Ergospirometer was used to assess physiological responses (heart rate and oxygen consumption [V02])' Nine recorded forces and nine experimental conditions formed the basis of this study, with subjects required to push three loads (200kg, 350kg, 500kg) at three frequencies (1120 sec, 1/40 sec, 1/60 sec) at a speed of 3.6km.h-1 over 14 metres on a co-efficient of friction controlled walkway for six minutes. Gait analysis, along with perceptions of exertion (,Central ' and 'Local' RPE) were collected during the third and sixth minutes of each condition . Body discomfort and contribution were identified upon completion of each condition. The results demonstrated that load and frequency interacted to influence responses within each domain. Increasing loads required increased force output during each stage of the push, which had a concomitant effect on physiological and perceptual responses. Significant differences arose between the initial, sustained and ending forces for each load, showing the direct relationship between load and force exertion. The combination of heaviest load/quickest frequency required the greatest physiological output, exceeding recommended guidelines for heart rate, V02 and energy expenditure responses. Intermediate combinations required moderate and acceptable energy cost. Linear relationships were established between heart rate and oxygen consumption , as well as between load and V02 , thus providing industrial practitioners an opportunity to evaluate task demands in situ. The combination of high forces and elevated physiological responses increased the subjective rating of the condition. The results emphasise the need to holistically consider all contributing factors in a dynamic pushing task. Dynamic pushing tasks place biomechanical, physiological and perceptual demands on the human operator, which must be minimised in order to ensure that this form of manual materials handling becomes sustainable in the long term.
- Full Text:
- Date Issued: 2007
- Authors: Cripwell, Adam Michael
- Date: 2007
- Subjects: Work -- Physiological aspects , Psychophysiology , Human engineering , Biomechanics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5144 , http://hdl.handle.net/10962/d1008183 , Work -- Physiological aspects , Psychophysiology , Human engineering , Biomechanics
- Description: The objective of the present research was to establish the biomechanical, physiological and perceptual responses of male operators to dynamic pushing tasks. The pushing tasks were performed using an industrial pallet jack with varying load/frequency combinations, in a controlled laboratory environment. Thirty healthy male subjects comprised the sample. Experimental procedures were conducted utilising the Chatillon ™ Dynamometer to measure force output in the initial, sustained and ending phases. The K4b2 Ergospirometer was used to assess physiological responses (heart rate and oxygen consumption [V02])' Nine recorded forces and nine experimental conditions formed the basis of this study, with subjects required to push three loads (200kg, 350kg, 500kg) at three frequencies (1120 sec, 1/40 sec, 1/60 sec) at a speed of 3.6km.h-1 over 14 metres on a co-efficient of friction controlled walkway for six minutes. Gait analysis, along with perceptions of exertion (,Central ' and 'Local' RPE) were collected during the third and sixth minutes of each condition . Body discomfort and contribution were identified upon completion of each condition. The results demonstrated that load and frequency interacted to influence responses within each domain. Increasing loads required increased force output during each stage of the push, which had a concomitant effect on physiological and perceptual responses. Significant differences arose between the initial, sustained and ending forces for each load, showing the direct relationship between load and force exertion. The combination of heaviest load/quickest frequency required the greatest physiological output, exceeding recommended guidelines for heart rate, V02 and energy expenditure responses. Intermediate combinations required moderate and acceptable energy cost. Linear relationships were established between heart rate and oxygen consumption , as well as between load and V02 , thus providing industrial practitioners an opportunity to evaluate task demands in situ. The combination of high forces and elevated physiological responses increased the subjective rating of the condition. The results emphasise the need to holistically consider all contributing factors in a dynamic pushing task. Dynamic pushing tasks place biomechanical, physiological and perceptual demands on the human operator, which must be minimised in order to ensure that this form of manual materials handling becomes sustainable in the long term.
- Full Text:
- Date Issued: 2007
The development of an entrepreneurial management model to promote the survival and growth of family estate wine businesses in the South African wine industry
- Cullen, Margaret Diane Munro
- Authors: Cullen, Margaret Diane Munro
- Date: 2006
- Subjects: Family-owned business enterprises -- South Africa , Wine industry -- South Africa -- Management , Entrepreneurship
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8766 , http://hdl.handle.net/10948/491 , http://hdl.handle.net/10948/d1011909 , Family-owned business enterprises -- South Africa , Wine industry -- South Africa -- Management , Entrepreneurship
- Description: The South African wine industry is polarised into the quantity-producing majority and the quality-conscious minority [Hughes, 2003]. The qualityproducing sector of the South African wine industry is dominated by family businesses. Research shows that there are approximately ninety familyowned wineries in South Africa. By international standards, South Africa is viewed as a quantity, not quality producing wine country, which will make it difficult to survive in an industry where quality is paramount for recognition. The ‘trailblazers’ of the international wine industry are family owned wineries [Robinson, 2000]. Twenty five percent of the 2003 five star South African wines were made by individuals or family wineries [Hughes, 2003], emphasising the growing importance of family wineries in the production of quality wines. It is important now, more than ever, with the industry opening up internationally, that survival of the family-owned wineries and their production of icon wines are promoted so that they can become flagship producers of the industry. The achievement of international status as a quality producing country, as well as building an industry based on the longevity of wine producing families, as well as a nation of wine lovers in South Africa should result.
- Full Text:
- Date Issued: 2006
- Authors: Cullen, Margaret Diane Munro
- Date: 2006
- Subjects: Family-owned business enterprises -- South Africa , Wine industry -- South Africa -- Management , Entrepreneurship
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8766 , http://hdl.handle.net/10948/491 , http://hdl.handle.net/10948/d1011909 , Family-owned business enterprises -- South Africa , Wine industry -- South Africa -- Management , Entrepreneurship
- Description: The South African wine industry is polarised into the quantity-producing majority and the quality-conscious minority [Hughes, 2003]. The qualityproducing sector of the South African wine industry is dominated by family businesses. Research shows that there are approximately ninety familyowned wineries in South Africa. By international standards, South Africa is viewed as a quantity, not quality producing wine country, which will make it difficult to survive in an industry where quality is paramount for recognition. The ‘trailblazers’ of the international wine industry are family owned wineries [Robinson, 2000]. Twenty five percent of the 2003 five star South African wines were made by individuals or family wineries [Hughes, 2003], emphasising the growing importance of family wineries in the production of quality wines. It is important now, more than ever, with the industry opening up internationally, that survival of the family-owned wineries and their production of icon wines are promoted so that they can become flagship producers of the industry. The achievement of international status as a quality producing country, as well as building an industry based on the longevity of wine producing families, as well as a nation of wine lovers in South Africa should result.
- Full Text:
- Date Issued: 2006
A journey with an abused child : a non-directive play therapy perspective
- Authors: Currin, Lisa Natalie
- Date: 2006
- Subjects: Play therapy -- South Africa , Child sexual abuse -- South Africa -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9847 , http://hdl.handle.net/10948/434 , Play therapy -- South Africa , Child sexual abuse -- South Africa -- Psychological aspects
- Description: The extensive amount of research conducted in the field of family violence internationally indicates that child abuse has a detrimental effect on both the physical and emotional development of children as well as having a profound effect on an individual’s psychological development and functioning in adult life. The aim of this research study was to describe the therapeutic process that unfolded with a seven year old allegedly abused female client within the framework of non-directive play therapy. The case was further contextualised utilising Erik Erikson’s theory of psychosocial development. This study served to broaden the body of psychotherapeutic knowledge by means of meaningful qualitative enquiry. The client was referred for therapy because of severe emotional and behavioural problems following the alleged sexual abuse. The client was seen over a period of eight months and this included 11 sessions of non-directive play therapy, three parent interviews and psychometric assessments conducted by a colleague. The case study method was utilised in this study. To achieve the aim of the research, the methodology of choice was the descriptive dialogic case study. A purposive sampling technique was used in the selection of the research subject for this study. The data collection and analysis were conducted according to Yin’s (1994) analytical generalisation, which consists of two main strategies: (a) using a theoretical framework as a guide to determine what data is relevant; and (b) developing a matrix as a descriptive framework for organising and integrating the data. Furthermore, the process of data analysis was aided by the use of guidelines proposed by Irving Alexander (1988) with Axline’s non-directive play therapy and Erikson’s theory of psychosocial development as the theoretical frameworks. The findings of this study suggest that plotting the play therapy sessions according to the framework of the four stages of play therapy was a particularly useful tool to monitor Michelle’s progression through the therapeutic process. This can be seen as a valuable application of a tool which can be used within the non-directive play therapy approach. Contextualising Michelle’s development according to the stages of Erikson’s theory of psychosocial development was also found to be a valuable endeavour. According to her chronological age, Michelle should have been in the fourth stage of industry versus inferiority, but in reality Michelle was still struggling to strike a healthy balance between the terms of conflict of trust versus mistrust issues of the first stage. From a therapeutic point, this was an important exercise as it helped to inform the therapist and consequently, the therapeutic process. This research undertaking can be recognised as a positive demonstration of the value of non-directive play therapy (Virginia Axline) and Erik Erikson’s theory of psychosocial development in the therapeutic process. In addition, this study has served to facilitate a more holistic understanding of the case study approach to research. Recommendations regarding future research undertakings that utilise the case study approach and methodology have been made. Key concepts: child abuse; family violence; non-directive play therapy; Erik Erikson’s theory of psychosocial development; analytical generalisation; case study research.
- Full Text:
- Date Issued: 2006
- Authors: Currin, Lisa Natalie
- Date: 2006
- Subjects: Play therapy -- South Africa , Child sexual abuse -- South Africa -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9847 , http://hdl.handle.net/10948/434 , Play therapy -- South Africa , Child sexual abuse -- South Africa -- Psychological aspects
- Description: The extensive amount of research conducted in the field of family violence internationally indicates that child abuse has a detrimental effect on both the physical and emotional development of children as well as having a profound effect on an individual’s psychological development and functioning in adult life. The aim of this research study was to describe the therapeutic process that unfolded with a seven year old allegedly abused female client within the framework of non-directive play therapy. The case was further contextualised utilising Erik Erikson’s theory of psychosocial development. This study served to broaden the body of psychotherapeutic knowledge by means of meaningful qualitative enquiry. The client was referred for therapy because of severe emotional and behavioural problems following the alleged sexual abuse. The client was seen over a period of eight months and this included 11 sessions of non-directive play therapy, three parent interviews and psychometric assessments conducted by a colleague. The case study method was utilised in this study. To achieve the aim of the research, the methodology of choice was the descriptive dialogic case study. A purposive sampling technique was used in the selection of the research subject for this study. The data collection and analysis were conducted according to Yin’s (1994) analytical generalisation, which consists of two main strategies: (a) using a theoretical framework as a guide to determine what data is relevant; and (b) developing a matrix as a descriptive framework for organising and integrating the data. Furthermore, the process of data analysis was aided by the use of guidelines proposed by Irving Alexander (1988) with Axline’s non-directive play therapy and Erikson’s theory of psychosocial development as the theoretical frameworks. The findings of this study suggest that plotting the play therapy sessions according to the framework of the four stages of play therapy was a particularly useful tool to monitor Michelle’s progression through the therapeutic process. This can be seen as a valuable application of a tool which can be used within the non-directive play therapy approach. Contextualising Michelle’s development according to the stages of Erikson’s theory of psychosocial development was also found to be a valuable endeavour. According to her chronological age, Michelle should have been in the fourth stage of industry versus inferiority, but in reality Michelle was still struggling to strike a healthy balance between the terms of conflict of trust versus mistrust issues of the first stage. From a therapeutic point, this was an important exercise as it helped to inform the therapist and consequently, the therapeutic process. This research undertaking can be recognised as a positive demonstration of the value of non-directive play therapy (Virginia Axline) and Erik Erikson’s theory of psychosocial development in the therapeutic process. In addition, this study has served to facilitate a more holistic understanding of the case study approach to research. Recommendations regarding future research undertakings that utilise the case study approach and methodology have been made. Key concepts: child abuse; family violence; non-directive play therapy; Erik Erikson’s theory of psychosocial development; analytical generalisation; case study research.
- Full Text:
- Date Issued: 2006
Investigating the effects of the proliferation of commercial broadcasting on public service broadcasting: the case of Rivers State of Nigeria Broadcasting Corporation
- Authors: Da-Wariboko, Biobele
- Date: 2006
- Subjects: Nigerian Broadcasting Corporation , Broadcasting -- Social aspects -- Nigeria , Mass media -- Social aspects -- Nigeria , Radio Broadcasting -- Social aspects -- Nigeria , Radio in community development , Radio stations -- Nigeria , Radio broadcasting -- Rivers State (Nigeria) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3423 , http://hdl.handle.net/10962/d1002876 , Nigerian Broadcasting Corporation , Broadcasting -- Social aspects -- Nigeria , Mass media -- Social aspects -- Nigeria , Radio Broadcasting -- Social aspects -- Nigeria , Radio in community development , Radio stations -- Nigeria , Radio broadcasting -- Rivers State (Nigeria) -- History
- Description: 1992 marked a turning point in Nigeria’s broadcasting history as the country formally deregulated her broadcast space. However, it was not until March 2002 that the first commercial radio station was established in Rivers State, a broadcast environment hitherto monopolised by Radio Rivers. The coming of the first independent radio station in Rivers State in March 2002 was followed by the establishment of two other stations in October 2003 and November 2003 respectively. As important as these events in broadcasting in Rivers State are, however, media scholars have argued that in most societies where such change has taken place, public service broadcasters have tampered with their values of being an open space where individuals and groups can come together to be educated, informed, and entertained. This study investigates the extent to which the proliferation of commercial broadcasting outlets has affected Radio Rivers’ public service programming and scheduling. Using a combination of qualitative and quantitative research methods, through in-depth interviews and analysis of the mandate and programme schedules, the study established that while Radio Rivers still maintains some public service values, its current programming policy is driven by the need to compete with the commercial broadcasters. This is evidenced in the decrease in the programme space allocated to current affairs and educational programmes on the schedule, (the genre of public service broadcasting), and the increase in attention to advertisements and entertainment programmes, (the genre of commercial broadcasting). The study also confirms the adverse effects of dwindling financial resources as forcing public service radios to compromise on their public service values, as majority of programmes on Radio Rivers current programme schedules are now geared towards attracting advertisers rather than serving the public good and interests. However, the study proved that it is not in all cases that the entry of commercial broadcasters into Rivers State broadcast space has undermined Radio Rivers public service values. Indeed, in leading to the expansion of interactive, news, and the diversification of entertainment programmes spaces on Radio Rivers’ programming schedules, the proliferation of commercial broadcasters has yielded some positive effects on Radio Rivers public service values and contribution to the public sphere. The study further highlights the need for some policy reforms at Radio Rivers, such as the introduction of licence fees, increased government funding and loosening government’s current control over the station. In addition, there is the need for the edict establishing the station to be amended to reflect the current trends in broadcasting in Rivers State, and above all to reposition Radio Rivers to sustain public good and public interests in its programming.
- Full Text:
- Date Issued: 2006
- Authors: Da-Wariboko, Biobele
- Date: 2006
- Subjects: Nigerian Broadcasting Corporation , Broadcasting -- Social aspects -- Nigeria , Mass media -- Social aspects -- Nigeria , Radio Broadcasting -- Social aspects -- Nigeria , Radio in community development , Radio stations -- Nigeria , Radio broadcasting -- Rivers State (Nigeria) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3423 , http://hdl.handle.net/10962/d1002876 , Nigerian Broadcasting Corporation , Broadcasting -- Social aspects -- Nigeria , Mass media -- Social aspects -- Nigeria , Radio Broadcasting -- Social aspects -- Nigeria , Radio in community development , Radio stations -- Nigeria , Radio broadcasting -- Rivers State (Nigeria) -- History
- Description: 1992 marked a turning point in Nigeria’s broadcasting history as the country formally deregulated her broadcast space. However, it was not until March 2002 that the first commercial radio station was established in Rivers State, a broadcast environment hitherto monopolised by Radio Rivers. The coming of the first independent radio station in Rivers State in March 2002 was followed by the establishment of two other stations in October 2003 and November 2003 respectively. As important as these events in broadcasting in Rivers State are, however, media scholars have argued that in most societies where such change has taken place, public service broadcasters have tampered with their values of being an open space where individuals and groups can come together to be educated, informed, and entertained. This study investigates the extent to which the proliferation of commercial broadcasting outlets has affected Radio Rivers’ public service programming and scheduling. Using a combination of qualitative and quantitative research methods, through in-depth interviews and analysis of the mandate and programme schedules, the study established that while Radio Rivers still maintains some public service values, its current programming policy is driven by the need to compete with the commercial broadcasters. This is evidenced in the decrease in the programme space allocated to current affairs and educational programmes on the schedule, (the genre of public service broadcasting), and the increase in attention to advertisements and entertainment programmes, (the genre of commercial broadcasting). The study also confirms the adverse effects of dwindling financial resources as forcing public service radios to compromise on their public service values, as majority of programmes on Radio Rivers current programme schedules are now geared towards attracting advertisers rather than serving the public good and interests. However, the study proved that it is not in all cases that the entry of commercial broadcasters into Rivers State broadcast space has undermined Radio Rivers public service values. Indeed, in leading to the expansion of interactive, news, and the diversification of entertainment programmes spaces on Radio Rivers’ programming schedules, the proliferation of commercial broadcasters has yielded some positive effects on Radio Rivers public service values and contribution to the public sphere. The study further highlights the need for some policy reforms at Radio Rivers, such as the introduction of licence fees, increased government funding and loosening government’s current control over the station. In addition, there is the need for the edict establishing the station to be amended to reflect the current trends in broadcasting in Rivers State, and above all to reposition Radio Rivers to sustain public good and public interests in its programming.
- Full Text:
- Date Issued: 2006
Non-steroidal anti-inflammatory agents, tolmetin and sulindac, inhibit liver tryptophan 2,3-dioxygenase activity and alter brain neurotransmitter levels
- Dairam, A, Antunes, Edith M, Saravanan, K S, Daya, Santylal
- Authors: Dairam, A , Antunes, Edith M , Saravanan, K S , Daya, Santylal
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6358 , http://hdl.handle.net/10962/d1006050 , http://dx.doi.org/10.1016/j.lfs.2006.07.028
- Description: Hepatic tryptophan 2,3-dioxygenase (TDO) is one of the rate-limiting enzymes in tryptophan catabolism and plays an important role in regulating the physiological flux of tryptophan into relevant metabolic pathways. In this study, we determined the effect of the non-steroidal anti-inflammatory agents, tolmetin and sulindac, on rat liver TDO activity and the subsequent changes in the hippocampal and striatal neurotransmitter levels. The amount of melatonin produced by the pineal gland was also measured using high performance liquid chromatography (HPLC). Treatment of rats with tolmetin or sulindac (5 mg/kg/bd for 5 days) significantly inhibited liver TDO activity. The results show that whilst tolmetin and sulindac increase serotonin levels in the hippocampus, these agents also significantly reduce dopamine levels in the striatum. Tolmetin, but not sulindac, increased the amount of melatonin produced by the pineal gland. The results of this study suggest that whilst tolmetin and sulindac may be beneficial for patients suffering from depression, these agents also have the potential to induce adverse effects in patients suffering with neurological disorders such as Parkinson's disease.
- Full Text:
- Date Issued: 2006
- Authors: Dairam, A , Antunes, Edith M , Saravanan, K S , Daya, Santylal
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6358 , http://hdl.handle.net/10962/d1006050 , http://dx.doi.org/10.1016/j.lfs.2006.07.028
- Description: Hepatic tryptophan 2,3-dioxygenase (TDO) is one of the rate-limiting enzymes in tryptophan catabolism and plays an important role in regulating the physiological flux of tryptophan into relevant metabolic pathways. In this study, we determined the effect of the non-steroidal anti-inflammatory agents, tolmetin and sulindac, on rat liver TDO activity and the subsequent changes in the hippocampal and striatal neurotransmitter levels. The amount of melatonin produced by the pineal gland was also measured using high performance liquid chromatography (HPLC). Treatment of rats with tolmetin or sulindac (5 mg/kg/bd for 5 days) significantly inhibited liver TDO activity. The results show that whilst tolmetin and sulindac increase serotonin levels in the hippocampus, these agents also significantly reduce dopamine levels in the striatum. Tolmetin, but not sulindac, increased the amount of melatonin produced by the pineal gland. The results of this study suggest that whilst tolmetin and sulindac may be beneficial for patients suffering from depression, these agents also have the potential to induce adverse effects in patients suffering with neurological disorders such as Parkinson's disease.
- Full Text:
- Date Issued: 2006
An investigation into the neuroprotective properties of the non-steroidal anti-inflammatory agents tolmetin, sulindac and turmeric
- Authors: Dairam, Amichand
- Date: 2006
- Subjects: Nonsteroidal anti-inflammatory agents Antioxidants Tolmetin -- Therapeutic use Sulindac -- Therapeutic use Turmeric -- Therapeutic use Nervous system -- Degeneration -- Prevention Alzheimer's disease
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3752 , http://hdl.handle.net/10962/d1003230
- Description: Accumulating evidence suggests that anti-inflammatory agents and antioxidants have neuroprotective properties and may be beneficial in the treatment of neurodegenerative disorders. In the present study, the possible neuroprotective properties of tolmetin, sulindac and turmeric were investigated. The antioxidant effects of tolmetin and sulindac were determined by inducing free radical generation with quinolinic acid (QA), cyanide or iron (II) in rat brain homogenates or primary hippocampal neurons. Tolmetin and sulindac significantly reduce lipid peroxidation and scavenge the superoxide anion. Metal binding studies were conducted to determine whether metal chelation is a possible mechanism through which these agents reduce QA and iron (II)-induced lipid peroxidation. UV/VIS, infrared spectroscopy as well as electrochemical studies show that both agents bind to iron (II) and/or iron (III). Histological examination of the hippocampus showed that pre-treatment of animals with tolmetin or sulindac offers protection against intrahippocampal injections of QA. These agents also attenuate QA-induced apoptosis and reduce the loss of neurons in the hippocampus. The co-incubation of primary hippocampal neurons with the NSAIDS also enhanced cell viability which is significantly reduced by QA. Behavioural studies using a water maze showed that the treatment of animals after QA-induced neurotoxicity reduces QA-induced spatial memory loss. Tolmetin and sulindac also reduced glutathione depletion and protein oxidation in rat hippocampus. Both NSAIDS inhibit liver tryptophan 2,3-dioxygenase activity in vitro and in vivo and subsequently increased hippocampal serotonin levels. However, both NSAIDS also reduce dopamine levels in rat striatum. Tolmetin but not sulindac increased the synthesis of melatonin by the pineal gland. The active components of turmeric known as the curcuminoids were separated using preparative thin layer chromatography (TLC). The purity was confirmed by TLC, NMR and mass spectrometry. The environmental toxin lead, induces lipid peroxidation and reduces primary hippocampal neuronal viability. The co-incubation of the neurons with the curcuminoids significantly reduces lead-induced lipid peroxidation and enhances neuronal cell viability in the presence of lead. Lead-induced spatial memory deficit is also attenuated with curcumin, demethoxycurcumin but not bisdemethoxycurcumin. The curcuminoids also reduce lead-induced hippocampal glutathione depletion and protein oxidation. Metal binding studies show that the curcuminoids bind to lead and is another possible mechanism through which the curcuminoids reduce lead-induced neurotoxicity. The findings of this study indicate a possible role of tolmetin, sulindac and turmeric in neurodegenerative disorders such as Alzheimer’s disease. However, tolmetin and sulindac reduce dopamine levels.
- Full Text:
- Date Issued: 2006
- Authors: Dairam, Amichand
- Date: 2006
- Subjects: Nonsteroidal anti-inflammatory agents Antioxidants Tolmetin -- Therapeutic use Sulindac -- Therapeutic use Turmeric -- Therapeutic use Nervous system -- Degeneration -- Prevention Alzheimer's disease
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3752 , http://hdl.handle.net/10962/d1003230
- Description: Accumulating evidence suggests that anti-inflammatory agents and antioxidants have neuroprotective properties and may be beneficial in the treatment of neurodegenerative disorders. In the present study, the possible neuroprotective properties of tolmetin, sulindac and turmeric were investigated. The antioxidant effects of tolmetin and sulindac were determined by inducing free radical generation with quinolinic acid (QA), cyanide or iron (II) in rat brain homogenates or primary hippocampal neurons. Tolmetin and sulindac significantly reduce lipid peroxidation and scavenge the superoxide anion. Metal binding studies were conducted to determine whether metal chelation is a possible mechanism through which these agents reduce QA and iron (II)-induced lipid peroxidation. UV/VIS, infrared spectroscopy as well as electrochemical studies show that both agents bind to iron (II) and/or iron (III). Histological examination of the hippocampus showed that pre-treatment of animals with tolmetin or sulindac offers protection against intrahippocampal injections of QA. These agents also attenuate QA-induced apoptosis and reduce the loss of neurons in the hippocampus. The co-incubation of primary hippocampal neurons with the NSAIDS also enhanced cell viability which is significantly reduced by QA. Behavioural studies using a water maze showed that the treatment of animals after QA-induced neurotoxicity reduces QA-induced spatial memory loss. Tolmetin and sulindac also reduced glutathione depletion and protein oxidation in rat hippocampus. Both NSAIDS inhibit liver tryptophan 2,3-dioxygenase activity in vitro and in vivo and subsequently increased hippocampal serotonin levels. However, both NSAIDS also reduce dopamine levels in rat striatum. Tolmetin but not sulindac increased the synthesis of melatonin by the pineal gland. The active components of turmeric known as the curcuminoids were separated using preparative thin layer chromatography (TLC). The purity was confirmed by TLC, NMR and mass spectrometry. The environmental toxin lead, induces lipid peroxidation and reduces primary hippocampal neuronal viability. The co-incubation of the neurons with the curcuminoids significantly reduces lead-induced lipid peroxidation and enhances neuronal cell viability in the presence of lead. Lead-induced spatial memory deficit is also attenuated with curcumin, demethoxycurcumin but not bisdemethoxycurcumin. The curcuminoids also reduce lead-induced hippocampal glutathione depletion and protein oxidation. Metal binding studies show that the curcuminoids bind to lead and is another possible mechanism through which the curcuminoids reduce lead-induced neurotoxicity. The findings of this study indicate a possible role of tolmetin, sulindac and turmeric in neurodegenerative disorders such as Alzheimer’s disease. However, tolmetin and sulindac reduce dopamine levels.
- Full Text:
- Date Issued: 2006
From 'here and now' to there and then : the evaluation of the effectiveness of Ehlers and Clark's model for treating PTSD in a rape survivor
- Authors: Davidow, Amy
- Date: 2006
- Subjects: Post-traumatic stress disorder -- Treatment -- South Africa , Rape trauma syndrome -- Treatment -- South Africa , Psychotherapy -- South Africa , Cognitive therapy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2961 , http://hdl.handle.net/10962/d1002470 , Post-traumatic stress disorder -- Treatment -- South Africa , Rape trauma syndrome -- Treatment -- South Africa , Psychotherapy -- South Africa , Cognitive therapy
- Description: The purpose of this research is to document the response of a rape survivor to a treatment based on Ehlers and Clark's (2000) therapy model and to use the material to evaluate the effectiveness of this kind of therapy in the South African context. In so doing, the specific local cultural and contextual factors, which may affect the overall effectiveness of the treatment, will be highlighted and discussed.
- Full Text:
- Date Issued: 2006
- Authors: Davidow, Amy
- Date: 2006
- Subjects: Post-traumatic stress disorder -- Treatment -- South Africa , Rape trauma syndrome -- Treatment -- South Africa , Psychotherapy -- South Africa , Cognitive therapy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2961 , http://hdl.handle.net/10962/d1002470 , Post-traumatic stress disorder -- Treatment -- South Africa , Rape trauma syndrome -- Treatment -- South Africa , Psychotherapy -- South Africa , Cognitive therapy
- Description: The purpose of this research is to document the response of a rape survivor to a treatment based on Ehlers and Clark's (2000) therapy model and to use the material to evaluate the effectiveness of this kind of therapy in the South African context. In so doing, the specific local cultural and contextual factors, which may affect the overall effectiveness of the treatment, will be highlighted and discussed.
- Full Text:
- Date Issued: 2006
Unstable ironies: narrative instability in Herman Charles Bosman's "Oom Schalk Lourens" series
- Authors: Davis, Rebecca
- Date: 2006
- Subjects: Bosman, Herman Charles, 1905-1951 -- Criticism and interpretation , Irony in literature , Narration (Rhetoric)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2215 , http://hdl.handle.net/10962/d1002258 , Bosman, Herman Charles, 1905-1951 -- Criticism and interpretation , Irony in literature , Narration (Rhetoric)
- Description: This thesis examines the narrative situation within Herman Charles Bosman’s “Oom Schalk Lourens” series of stories, focussing on the nature of the relationship between author and narrator. In particular, it seeks to trace the source of the multiple ironies at work in the texts. It has been customary for critics in the past to claim that the irony within the stories stems from Bosman, operating authorially ‘above’ Oom Schalk. In terms of this theory, Oom Schalk is read as being largely unaware of the inconsistencies and contradictions within his narrative. It is the claim of this thesis, however, that Oom Schalk is the self-aware creator of the texts’ ironies much of the time. Chapter 1 commences with an attempt at defining irony, and provides a brief overview of the history of its deployment within South African literature before discussing the literary genre which Bosman was to exploit as his ironic vehicle: the “oral-style” short story. Chapter 2 examines Wayne C. Booth’s notions of “stable” and “unstable” irony: the irony of the Oom Schalk stories has, in the past, been classified as belonging to the former category, but this thesis attempts to show that its inconsistent deployment within the stories consigns it more accurately to the latter. Chapter 3 offers an assessment of the extrinsic contexts relevant to the analysis: the context of the stories’ publication, and the likely composition of Bosman’s reading public. Chapter 4 begins to examine the distance between implied author and implied narrator in the stories. Chapters 5, 6 and 7 subject stories dealing with the themes of art, race and land to detailed analysis in order to examine the shifting – and progressively, though unevenly, diminishing – distance between Bosman and Oom Schalk. The thesis concludes that the degree to which the ironic distance between author and narrator fluctuates within, and between, the stories, results in a narrative situation which must be classified as fundamentally unstable.
- Full Text:
- Date Issued: 2006
- Authors: Davis, Rebecca
- Date: 2006
- Subjects: Bosman, Herman Charles, 1905-1951 -- Criticism and interpretation , Irony in literature , Narration (Rhetoric)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2215 , http://hdl.handle.net/10962/d1002258 , Bosman, Herman Charles, 1905-1951 -- Criticism and interpretation , Irony in literature , Narration (Rhetoric)
- Description: This thesis examines the narrative situation within Herman Charles Bosman’s “Oom Schalk Lourens” series of stories, focussing on the nature of the relationship between author and narrator. In particular, it seeks to trace the source of the multiple ironies at work in the texts. It has been customary for critics in the past to claim that the irony within the stories stems from Bosman, operating authorially ‘above’ Oom Schalk. In terms of this theory, Oom Schalk is read as being largely unaware of the inconsistencies and contradictions within his narrative. It is the claim of this thesis, however, that Oom Schalk is the self-aware creator of the texts’ ironies much of the time. Chapter 1 commences with an attempt at defining irony, and provides a brief overview of the history of its deployment within South African literature before discussing the literary genre which Bosman was to exploit as his ironic vehicle: the “oral-style” short story. Chapter 2 examines Wayne C. Booth’s notions of “stable” and “unstable” irony: the irony of the Oom Schalk stories has, in the past, been classified as belonging to the former category, but this thesis attempts to show that its inconsistent deployment within the stories consigns it more accurately to the latter. Chapter 3 offers an assessment of the extrinsic contexts relevant to the analysis: the context of the stories’ publication, and the likely composition of Bosman’s reading public. Chapter 4 begins to examine the distance between implied author and implied narrator in the stories. Chapters 5, 6 and 7 subject stories dealing with the themes of art, race and land to detailed analysis in order to examine the shifting – and progressively, though unevenly, diminishing – distance between Bosman and Oom Schalk. The thesis concludes that the degree to which the ironic distance between author and narrator fluctuates within, and between, the stories, results in a narrative situation which must be classified as fundamentally unstable.
- Full Text:
- Date Issued: 2006
Codeswitching, borrowing and mixing in a corpus of Xhosa English
- Authors: De Klerk, Vivian A
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6130 , http://hdl.handle.net/10962/d1011582
- Description: The paper analyses selected aspects of the codeswitching behaviour in a spoken corpus of the English of 326 people, all of them mother-tongue speakers of Xhosa (a local African language in South Africa), and all of whom would see themselves as Xhosa/English bilinguals. The corpus comprises approximately 550,000 transcribed words of spontaneous, relaxed, oral discourse in English between pairs of Xhosaspeaking interlocutors, discussing a wide range of topics. While the usual pattern in bilingual speech is to use the L1 as matrix language and the L2 as embedded language, in this corpus the opposite is the case, as interlocutors were interviewed in English (the L2). The corpus therefore offers a ‘mirror image’, in a sense, of normal codeswitching behaviour. Using Wordsmith (a concordancer programme), all incidences of codeswitching into Xhosa during these conversations were identified and analysed in an effort to reveal underlying patterns. Examination of the amount and nature of codeswitching in the corpus promised to throw some light on the extent to which participants are genuinely bilingual, in terms of their ability to converse comfortably in English.
- Full Text:
- Date Issued: 2006
- Authors: De Klerk, Vivian A
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6130 , http://hdl.handle.net/10962/d1011582
- Description: The paper analyses selected aspects of the codeswitching behaviour in a spoken corpus of the English of 326 people, all of them mother-tongue speakers of Xhosa (a local African language in South Africa), and all of whom would see themselves as Xhosa/English bilinguals. The corpus comprises approximately 550,000 transcribed words of spontaneous, relaxed, oral discourse in English between pairs of Xhosaspeaking interlocutors, discussing a wide range of topics. While the usual pattern in bilingual speech is to use the L1 as matrix language and the L2 as embedded language, in this corpus the opposite is the case, as interlocutors were interviewed in English (the L2). The corpus therefore offers a ‘mirror image’, in a sense, of normal codeswitching behaviour. Using Wordsmith (a concordancer programme), all incidences of codeswitching into Xhosa during these conversations were identified and analysed in an effort to reveal underlying patterns. Examination of the amount and nature of codeswitching in the corpus promised to throw some light on the extent to which participants are genuinely bilingual, in terms of their ability to converse comfortably in English.
- Full Text:
- Date Issued: 2006
Shark fishing effort and catch of the ragged-tooth shark Carcharias taurus in the South African competitive shore-angling fishery
- Dicken, Matthew L, Booth, Anthony J, Smale, Malcolm J
- Authors: Dicken, Matthew L , Booth, Anthony J , Smale, Malcolm J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126944 , vital:35937 , https://doi.10.2989/18142320609504209
- Description: In South Africa, Carcharias taurus is commonly known as the ragged-tooth shark or raggie. The species is also referred to as the sand-tiger shark in North America and as the grey-nurse shark in Australia. It is a long-lived species with an estimated longevity of up to 40 years (Goldman 2002). Female sharks reach sexual maturity at approximately 10 years (Goldman 2002), and they exhibit a biennial reproductive cycle (Branstetter and Musick 1994, Lucifora et al. 2002, G Cliff, Natal Sharks Board, unpublished data). Intra-uterine cannibalisation results in a maximum fecundity of two pups per litter after a gestation period of approximately 9–12 months (Bass et al. 1975, Gilmore et al. 1983). These life-history characteristics make this species particularly susceptible to overexploitation.
- Full Text:
- Date Issued: 2010
- Authors: Dicken, Matthew L , Booth, Anthony J , Smale, Malcolm J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126944 , vital:35937 , https://doi.10.2989/18142320609504209
- Description: In South Africa, Carcharias taurus is commonly known as the ragged-tooth shark or raggie. The species is also referred to as the sand-tiger shark in North America and as the grey-nurse shark in Australia. It is a long-lived species with an estimated longevity of up to 40 years (Goldman 2002). Female sharks reach sexual maturity at approximately 10 years (Goldman 2002), and they exhibit a biennial reproductive cycle (Branstetter and Musick 1994, Lucifora et al. 2002, G Cliff, Natal Sharks Board, unpublished data). Intra-uterine cannibalisation results in a maximum fecundity of two pups per litter after a gestation period of approximately 9–12 months (Bass et al. 1975, Gilmore et al. 1983). These life-history characteristics make this species particularly susceptible to overexploitation.
- Full Text:
- Date Issued: 2010
Spatial and seasonal distribution patterns of the ragged-tooth shark Carcharias taurus along the coast of South Africa
- Dicken, Matthew L, Booth, Anthony J, Smale, Malcolm J
- Authors: Dicken, Matthew L , Booth, Anthony J , Smale, Malcolm J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127008 , vital:35943 , https://doi.10.2989/18142320609504210
- Description: Off South Africa, the ragged-tooth shark Carcharias Taurus has been occasionally reported from the West Coast, but it is more commonly found along the East and South coasts from Cape Town to northern KwaZulu-Natal (KZN) (Bass et al. 1975, Smale 2002). Mating is thought to occur off the south coast of KZN from October to late November (G Cliff, Natal Sharks Board, unpublished data). Pregnant females then move northward to spend the early part of their gestation in the warmer waters of northern KZN and possibly southern Moçambique. During July and August, the near-term pregnant females begin to move southwards towards the cooler waters of the Eastern Cape (Wallett 1973, Bass et al. 1975, G Cliff, unpublished data), where they give birth from September to November (Smale 2002). After parturition, many of the females migrate back to KZN. The whereabouts of mature males outside of the mating season is unclear. These broadscale distribution and migratory habits for C. taurus have been inferred from limited catch records obtained for only parts of its range along the South African coast.
- Full Text:
- Date Issued: 2010
- Authors: Dicken, Matthew L , Booth, Anthony J , Smale, Malcolm J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127008 , vital:35943 , https://doi.10.2989/18142320609504210
- Description: Off South Africa, the ragged-tooth shark Carcharias Taurus has been occasionally reported from the West Coast, but it is more commonly found along the East and South coasts from Cape Town to northern KwaZulu-Natal (KZN) (Bass et al. 1975, Smale 2002). Mating is thought to occur off the south coast of KZN from October to late November (G Cliff, Natal Sharks Board, unpublished data). Pregnant females then move northward to spend the early part of their gestation in the warmer waters of northern KZN and possibly southern Moçambique. During July and August, the near-term pregnant females begin to move southwards towards the cooler waters of the Eastern Cape (Wallett 1973, Bass et al. 1975, G Cliff, unpublished data), where they give birth from September to November (Smale 2002). After parturition, many of the females migrate back to KZN. The whereabouts of mature males outside of the mating season is unclear. These broadscale distribution and migratory habits for C. taurus have been inferred from limited catch records obtained for only parts of its range along the South African coast.
- Full Text:
- Date Issued: 2010
Preliminary observations of tag shedding, tag reporting, tag wounds, and tag biofouling for raggedtooth sharks (Carcharias taurus) tagged off the east coast of South Africa
- Dicken, Matthew Laurence, Booth, Anthony J, Smale, Malcolm John
- Authors: Dicken, Matthew Laurence , Booth, Anthony J , Smale, Malcolm John
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125774 , vital:35816 , https://doi.10.1016/j.icesjms.2006.06.009
- Description: Mark-recapture models do not distinguish how ‘‘deaths’’ accrue to marked animals in the population. If animals lose their tags, then recaptures will be fewer than expected and estimates of survival will be underestimated (Arnason and Mills, 1981; McDonald et al., 2003). Similarly, if the non-reporting rate is unknown and assumed to be negligible, as is the case in some tagging studies (e.g. Cliff et al., 1996, for white sharks Carcharodon carcharias), the probability of capture can be underestimated. The effects of both these problems, inherent in cooperative tagging programmes, lead to too few tagged fish being recovered, with a positive bias on the estimation of population size. These effects are most pronounced when capture probability is low and fewer tags are available for recapture (McDonald et al., 2003).
- Full Text:
- Date Issued: 2006
- Authors: Dicken, Matthew Laurence , Booth, Anthony J , Smale, Malcolm John
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125774 , vital:35816 , https://doi.10.1016/j.icesjms.2006.06.009
- Description: Mark-recapture models do not distinguish how ‘‘deaths’’ accrue to marked animals in the population. If animals lose their tags, then recaptures will be fewer than expected and estimates of survival will be underestimated (Arnason and Mills, 1981; McDonald et al., 2003). Similarly, if the non-reporting rate is unknown and assumed to be negligible, as is the case in some tagging studies (e.g. Cliff et al., 1996, for white sharks Carcharodon carcharias), the probability of capture can be underestimated. The effects of both these problems, inherent in cooperative tagging programmes, lead to too few tagged fish being recovered, with a positive bias on the estimation of population size. These effects are most pronounced when capture probability is low and fewer tags are available for recapture (McDonald et al., 2003).
- Full Text:
- Date Issued: 2006
Population dynamics of the raggedtooth shark (carcharias taurus) along the east coast of South Africa
- Authors: Dicken, Matthew Laurence
- Date: 2006
- Subjects: Sharks -- South Africa Shark fisheries -- South Africa Fish populations -- South Africa Sand tiger shark Fish tagging -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5310 , http://hdl.handle.net/10962/d1005155
- Description: This thesis develops the first open population model for any shark species worldwide using the Cormack-Jolly-Seber (CJS) model. In conjunction with a tagging study, five auxiliary studies were conducted to investigate stock structure, post-release mortality, tag shedding, and tag-reporting rates. The results from each of the studies were used to correct for any violations of the models assumptions to provide the first unbiased estimates of survival and abundance for the raggedtooth shark (Carcharias taurus) in South Africa. The C. taurus population exhibited complex stock structuring, by size and sex. Competitive shore anglers fished an estimated 37, 820 fishing days.year⁻¹ (95% C.I. = 28, 281 - 47, 359 days.year⁻¹) for sharks, and caught 1764 (95% C.I. = 321 – 3207) C. taurus. Although released alive, post-release mortality ranged from 3.85% for young-of-the-year sharks to 18.46% for adult sharks. Between 1984 and 2004, a total of 3471 C. taurus were tagged. In all, 302-tagged sharks (8.7%) were recaptured. Both juvenile (< 1.8 m TL) and adult sharks (> 1.8 m TL) displayed philopatric behaviour for specific parts of their ranges, including gestating and parturition areas. Significant differences were observed in the percentage of recaptures between the different tag types, tagging programs, individual taggers and capture methods used to tag sharks. The annual tag retention rate for juvenile sharks, 94.19% (95% C.I. = 80.68% - 100.00%) was significantly higher than for adult sharks, estimated at 29.00% (95% C.I. = 6.76% - 64.39%). Tag reporting rates, from fishermen varied both spatially and temporally from 0.28 (95% C.I. = 0.00 – 0.63) to 0.77 (95% C.I. = 0.56 – 0.97). Associated tag wound damage and biofouling growth indicated that B-type tags were a suitable tag type for use on C. taurus, whereas C-type tags were not. The CJS bias-adjusted estimate for juvenile survival was 0.456 (95% C.I. = 0.367 – 0.516) and for adult sharks, 0.865 (95% C.I. = 0.795 – 0.915). From 1984 to 2004 the mean bias-adjusted population size for juvenile sharks was estimated at 3506 (95% C.I. = 2433 – 4350) and for adult sharks, 5899 (95% C.I. = 7216 – 11904). Trends in abundance over the 20-year study period indicated a stable, healthy population.
- Full Text:
- Date Issued: 2006
- Authors: Dicken, Matthew Laurence
- Date: 2006
- Subjects: Sharks -- South Africa Shark fisheries -- South Africa Fish populations -- South Africa Sand tiger shark Fish tagging -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5310 , http://hdl.handle.net/10962/d1005155
- Description: This thesis develops the first open population model for any shark species worldwide using the Cormack-Jolly-Seber (CJS) model. In conjunction with a tagging study, five auxiliary studies were conducted to investigate stock structure, post-release mortality, tag shedding, and tag-reporting rates. The results from each of the studies were used to correct for any violations of the models assumptions to provide the first unbiased estimates of survival and abundance for the raggedtooth shark (Carcharias taurus) in South Africa. The C. taurus population exhibited complex stock structuring, by size and sex. Competitive shore anglers fished an estimated 37, 820 fishing days.year⁻¹ (95% C.I. = 28, 281 - 47, 359 days.year⁻¹) for sharks, and caught 1764 (95% C.I. = 321 – 3207) C. taurus. Although released alive, post-release mortality ranged from 3.85% for young-of-the-year sharks to 18.46% for adult sharks. Between 1984 and 2004, a total of 3471 C. taurus were tagged. In all, 302-tagged sharks (8.7%) were recaptured. Both juvenile (< 1.8 m TL) and adult sharks (> 1.8 m TL) displayed philopatric behaviour for specific parts of their ranges, including gestating and parturition areas. Significant differences were observed in the percentage of recaptures between the different tag types, tagging programs, individual taggers and capture methods used to tag sharks. The annual tag retention rate for juvenile sharks, 94.19% (95% C.I. = 80.68% - 100.00%) was significantly higher than for adult sharks, estimated at 29.00% (95% C.I. = 6.76% - 64.39%). Tag reporting rates, from fishermen varied both spatially and temporally from 0.28 (95% C.I. = 0.00 – 0.63) to 0.77 (95% C.I. = 0.56 – 0.97). Associated tag wound damage and biofouling growth indicated that B-type tags were a suitable tag type for use on C. taurus, whereas C-type tags were not. The CJS bias-adjusted estimate for juvenile survival was 0.456 (95% C.I. = 0.367 – 0.516) and for adult sharks, 0.865 (95% C.I. = 0.795 – 0.915). From 1984 to 2004 the mean bias-adjusted population size for juvenile sharks was estimated at 3506 (95% C.I. = 2433 – 4350) and for adult sharks, 5899 (95% C.I. = 7216 – 11904). Trends in abundance over the 20-year study period indicated a stable, healthy population.
- Full Text:
- Date Issued: 2006
An evaluation of a performance management and development system with reference to the Department of the Premier, Provincial Government Western Cape
- Authors: Dingwayo, Mzimkulu Sydney
- Date: 2006
- Subjects: Performance -- Management -- Evaluation , Performance -- Management , Employees -- Rating of
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8251 , http://hdl.handle.net/10948/495 , Performance -- Management -- Evaluation , Performance -- Management , Employees -- Rating of
- Description: We are living in a changing world. Performance management is becoming a major challenge for organisations. The aim of this study is to review the current status of the Performance Management and Development System at the Department of the Premier and to look into the reasons why it has become a pain rather than a gain to both the organisation and its employees. This document will also look at the possible causes of the failure of the performance management system and will then propose useful guidelines to overcome obstacles to the benefit of all the affected parties. To achieve this objective a comprehensive literature study was performed to the Department of the Premier to determine the views on performance, and on performance management programmes. The study also included an investigation into the extent to which a performance management programme should be aligned with Provincial Government Western Cape (PGWC) and individual goals. Questionnaires developed from the literature study, were distributed amongst randomly selected respondents, in order to determine the extent to which a specific directorate manages performance, in line with the guidelines provided by the literature study. The information obtained from the questionnaires were compared with the guidelines provided by the literature study in order to identify shortcomings in the influence that the performance management programme has on the achievement of Department and individual goals at the selected Directorates. The objective of this study was to evaluate the influence of the current performance management system, in the Department at Provincial Government Western Cape, as a facilitation tool in aiding or assisting management in achieving individual and departmental goals. To achieve this objective a comprehensive literature study was performed to determine the views on performance, and on performance management systems. A questionnaire was designed based on the guidelines in the literature study, in order to establish the extent to which the organisation manages performance. The completed questionnaires were returned and these were processed and analysed using Microsoft Office Excel 2003, running on the Windows XP suite of computer packages. The respondent’s opinion obtained from the questionnaires were compared with the guidelines provided by the literature study in order to identify shortcomings of the influence that the performance management system has on the achievement of individual and departmental goals at the selected organization. The research results indicate that the majority of staff supports and understands the process.
- Full Text:
- Date Issued: 2006
- Authors: Dingwayo, Mzimkulu Sydney
- Date: 2006
- Subjects: Performance -- Management -- Evaluation , Performance -- Management , Employees -- Rating of
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8251 , http://hdl.handle.net/10948/495 , Performance -- Management -- Evaluation , Performance -- Management , Employees -- Rating of
- Description: We are living in a changing world. Performance management is becoming a major challenge for organisations. The aim of this study is to review the current status of the Performance Management and Development System at the Department of the Premier and to look into the reasons why it has become a pain rather than a gain to both the organisation and its employees. This document will also look at the possible causes of the failure of the performance management system and will then propose useful guidelines to overcome obstacles to the benefit of all the affected parties. To achieve this objective a comprehensive literature study was performed to the Department of the Premier to determine the views on performance, and on performance management programmes. The study also included an investigation into the extent to which a performance management programme should be aligned with Provincial Government Western Cape (PGWC) and individual goals. Questionnaires developed from the literature study, were distributed amongst randomly selected respondents, in order to determine the extent to which a specific directorate manages performance, in line with the guidelines provided by the literature study. The information obtained from the questionnaires were compared with the guidelines provided by the literature study in order to identify shortcomings in the influence that the performance management programme has on the achievement of Department and individual goals at the selected Directorates. The objective of this study was to evaluate the influence of the current performance management system, in the Department at Provincial Government Western Cape, as a facilitation tool in aiding or assisting management in achieving individual and departmental goals. To achieve this objective a comprehensive literature study was performed to determine the views on performance, and on performance management systems. A questionnaire was designed based on the guidelines in the literature study, in order to establish the extent to which the organisation manages performance. The completed questionnaires were returned and these were processed and analysed using Microsoft Office Excel 2003, running on the Windows XP suite of computer packages. The respondent’s opinion obtained from the questionnaires were compared with the guidelines provided by the literature study in order to identify shortcomings of the influence that the performance management system has on the achievement of individual and departmental goals at the selected organization. The research results indicate that the majority of staff supports and understands the process.
- Full Text:
- Date Issued: 2006
Ceropegia macmasteri (Apocynaceae-Asclepiadoideae-Ceropegieae), a new species from Eastern Cape, South Africa
- Authors: Dold, Anthony P
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6515 , http://hdl.handle.net/10962/d1005943 , http://dx.doi.org/10.1016/j.sajb.2005.06.005
- Description: Ceropegia macmasteri, a new species from Cathcart in the Eastern Cape Province of South Africa, is only known from a single population in Dohne sourveld grassland where it occurs with another rare local endemic species of the Ceropegieae, Brachystelma cathcartense R.A.Dyer. The new species, an herbaceous grassland plant with a tuberous rootstock, most closely resembles C. stentiae E.A.Bruce, but is distinguished by its linear-erect corona lobes and inner corona conniving to form a central column.
- Full Text:
- Date Issued: 2006
- Authors: Dold, Anthony P
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6515 , http://hdl.handle.net/10962/d1005943 , http://dx.doi.org/10.1016/j.sajb.2005.06.005
- Description: Ceropegia macmasteri, a new species from Cathcart in the Eastern Cape Province of South Africa, is only known from a single population in Dohne sourveld grassland where it occurs with another rare local endemic species of the Ceropegieae, Brachystelma cathcartense R.A.Dyer. The new species, an herbaceous grassland plant with a tuberous rootstock, most closely resembles C. stentiae E.A.Bruce, but is distinguished by its linear-erect corona lobes and inner corona conniving to form a central column.
- Full Text:
- Date Issued: 2006
Establishing effective organisational coaching strategies
- Authors: Dove, Jean Tracy
- Date: 2006
- Subjects: Employees -- Coaching of , Mentoring in business , Employee retention , Organizational effectiveness
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8561 , http://hdl.handle.net/10948/496 , Employees -- Coaching of , Mentoring in business , Employee retention , Organizational effectiveness
- Description: To enable a business to grow and to uplift the economic and social development of its employees, it is vital that skills are provided to individuals. Businesses today strive to retain employees, as their skills learnt, prove to be a valuable asset that takes years to replace. For this reason, all means available are utilised to retain employees in the workplace. The term coaching is a relatively newcomer to the world of business and is seen to take a holistic view of the individual and focuses on work, corporate values, personal needs and career development. The main objective of this study was to identify coaching strategies that can be implemented by organisations in order to ensure the retention and development of employees. Businesses have to rely on employees to help them achieve financial growth, outperform their competitors, produce innovative products and to achieve long-term goals. These tasks would be impossible to achieve if the interests of employees were neglected. It was established from the literature survey that the coaching style of leadership involved more than simply training managers in coaching skills. A whole new coaching culture needed to be implemented in businesses in order to bring about change. Coachees rely on effective coachers to provide guidance and to demonstrate the skills needed. Based on various models in the literature survey a coaching model was formulated. The empirical survey was conducted at five selected companies in the Buffalo City Municipal area. A theoretical model for organisational coaching was developed and tested by means of a questionnaire. It emerged that employees at lower levels had not been involved in any form of coaching.
- Full Text:
- Date Issued: 2006
- Authors: Dove, Jean Tracy
- Date: 2006
- Subjects: Employees -- Coaching of , Mentoring in business , Employee retention , Organizational effectiveness
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8561 , http://hdl.handle.net/10948/496 , Employees -- Coaching of , Mentoring in business , Employee retention , Organizational effectiveness
- Description: To enable a business to grow and to uplift the economic and social development of its employees, it is vital that skills are provided to individuals. Businesses today strive to retain employees, as their skills learnt, prove to be a valuable asset that takes years to replace. For this reason, all means available are utilised to retain employees in the workplace. The term coaching is a relatively newcomer to the world of business and is seen to take a holistic view of the individual and focuses on work, corporate values, personal needs and career development. The main objective of this study was to identify coaching strategies that can be implemented by organisations in order to ensure the retention and development of employees. Businesses have to rely on employees to help them achieve financial growth, outperform their competitors, produce innovative products and to achieve long-term goals. These tasks would be impossible to achieve if the interests of employees were neglected. It was established from the literature survey that the coaching style of leadership involved more than simply training managers in coaching skills. A whole new coaching culture needed to be implemented in businesses in order to bring about change. Coachees rely on effective coachers to provide guidance and to demonstrate the skills needed. Based on various models in the literature survey a coaching model was formulated. The empirical survey was conducted at five selected companies in the Buffalo City Municipal area. A theoretical model for organisational coaching was developed and tested by means of a questionnaire. It emerged that employees at lower levels had not been involved in any form of coaching.
- Full Text:
- Date Issued: 2006
Valuation of communal area livestock benefits, rural livelihoods and related policy issues
- Dovie, Delali B K, Shackleton, Charlie M, Witkowski, Ed T F
- Authors: Dovie, Delali B K , Shackleton, Charlie M , Witkowski, Ed T F
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6627 , http://hdl.handle.net/10962/d1006819
- Description: The multiple benefits from livestock production to rural households are evaluated in Thorndale, a communal area of the Limpopo Province South Africa. Monetary values of livestock products are presented. Values from most previous studies are static (and thus outdated), as a result of conceptual and methodological shifts. The net monetary value of the direct benefits from livestock was estimated as $656 per household/annum, excluding the holding of cattle for savings. The net value is equivalent to 22.7% of the value of the other livelihood sources that were considered, and inclusive of cash income streams, crops, and secondary woodland resources. A net 168% herd increase in livestock was recorded between 1993 and 1999. More households owned goats compared to cattle, and cattle were important for use as draught power, and for milk. Households without livestock benefited through gifts and services, valued at $33 per household/annum. Policy concerns are the provision of adequate market and pricing mechanisms for communal area livestock, tailored savings, investment support, credit schemes, and infrastructure. An appropriate multipurpose benefit production model, other than a commercialised model is suggested for the sector.
- Full Text:
- Date Issued: 2006
- Authors: Dovie, Delali B K , Shackleton, Charlie M , Witkowski, Ed T F
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6627 , http://hdl.handle.net/10962/d1006819
- Description: The multiple benefits from livestock production to rural households are evaluated in Thorndale, a communal area of the Limpopo Province South Africa. Monetary values of livestock products are presented. Values from most previous studies are static (and thus outdated), as a result of conceptual and methodological shifts. The net monetary value of the direct benefits from livestock was estimated as $656 per household/annum, excluding the holding of cattle for savings. The net value is equivalent to 22.7% of the value of the other livelihood sources that were considered, and inclusive of cash income streams, crops, and secondary woodland resources. A net 168% herd increase in livestock was recorded between 1993 and 1999. More households owned goats compared to cattle, and cattle were important for use as draught power, and for milk. Households without livestock benefited through gifts and services, valued at $33 per household/annum. Policy concerns are the provision of adequate market and pricing mechanisms for communal area livestock, tailored savings, investment support, credit schemes, and infrastructure. An appropriate multipurpose benefit production model, other than a commercialised model is suggested for the sector.
- Full Text:
- Date Issued: 2006
An investigation of the in vitro anticancer properties of selected platinum compounds
- Authors: Du Plessis-Stoman, Debbie
- Date: 2006
- Subjects: Antineoplastic agents , Platinum compounds , Cancer -- Immunological aspects , Cancer -- Chemotherapy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10334 , http://hdl.handle.net/10948/498 , http://hdl.handle.net/10948/d1012002 , Antineoplastic agents , Platinum compounds , Cancer -- Immunological aspects , Cancer -- Chemotherapy
- Description: This dissertation mainly deals with some biochemical aspects regarding the efficacy of novel platinum anticancer compounds, as part of a broader study in which both chemistry and biochemistry are involved. Various novel diamine and N-S donor chelate compounds of platinum II and IV have been developed in which factors such as stereochemistry, ligand exchange rate and biocompatibility were considered as additional parameters. In the first order testing, each of these compounds was tested with reference to their “killing” potential by comparing their rate of killing, over a period of 48 hours with those of cisplatin and oxaliplatin. Some 80 compounds were tested in this way. Although only a few could be regarded as equal to or even better than cisplatin and oxaliplatin, the testing of these compounds on cancer cells provided useful knowledge for the further development of novel compounds. Four of the better compounds, namely Y9, Y14, Y16 and Lt16.2 were selected for further studies to obtain more detailed knowledge of their anticancer action, including some flow cytometric studies. In addition to the above, cisplatin resistant cells were produced for each of the three different cell lines tested, namely, HeLa, HT29 and MCF7 cancer cell lines, by intermittent and incremental exposure to cisplatin (all the cell lines tested became resistant to cisplatin). Each of the selected compounds were exposed to the cells in the same manner, in order to attempt the induction of resistance against these compounds in the three cell lines tested (i.e. whether these cells will become resistant to the various compounds). Each of these selected platinum containing compounds were subsequently tested against the “cisplatin resistant” cell lines in order to determine their efficacy against such cells. One such compound could be singled out, since cervical cancer cells (HeLa cells) do not become resistant to it. This behaviour is similar to that of oxaliplatin against cervical cancer and colon cancer (HT29) cells (oxaliplatin is the number one treatment for colon cancer at present). This compound also proved to be more active against cisplatin resistant cell lines. It was found that all the compounds induced apoptosis in the cell lines tested as well as inhibit the DNA cycle at one or more phase. Finally, an effort was made to evaluate the different compounds by comparing them with respect to their properties relating to anticancer action.
- Full Text:
- Date Issued: 2006
- Authors: Du Plessis-Stoman, Debbie
- Date: 2006
- Subjects: Antineoplastic agents , Platinum compounds , Cancer -- Immunological aspects , Cancer -- Chemotherapy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10334 , http://hdl.handle.net/10948/498 , http://hdl.handle.net/10948/d1012002 , Antineoplastic agents , Platinum compounds , Cancer -- Immunological aspects , Cancer -- Chemotherapy
- Description: This dissertation mainly deals with some biochemical aspects regarding the efficacy of novel platinum anticancer compounds, as part of a broader study in which both chemistry and biochemistry are involved. Various novel diamine and N-S donor chelate compounds of platinum II and IV have been developed in which factors such as stereochemistry, ligand exchange rate and biocompatibility were considered as additional parameters. In the first order testing, each of these compounds was tested with reference to their “killing” potential by comparing their rate of killing, over a period of 48 hours with those of cisplatin and oxaliplatin. Some 80 compounds were tested in this way. Although only a few could be regarded as equal to or even better than cisplatin and oxaliplatin, the testing of these compounds on cancer cells provided useful knowledge for the further development of novel compounds. Four of the better compounds, namely Y9, Y14, Y16 and Lt16.2 were selected for further studies to obtain more detailed knowledge of their anticancer action, including some flow cytometric studies. In addition to the above, cisplatin resistant cells were produced for each of the three different cell lines tested, namely, HeLa, HT29 and MCF7 cancer cell lines, by intermittent and incremental exposure to cisplatin (all the cell lines tested became resistant to cisplatin). Each of the selected compounds were exposed to the cells in the same manner, in order to attempt the induction of resistance against these compounds in the three cell lines tested (i.e. whether these cells will become resistant to the various compounds). Each of these selected platinum containing compounds were subsequently tested against the “cisplatin resistant” cell lines in order to determine their efficacy against such cells. One such compound could be singled out, since cervical cancer cells (HeLa cells) do not become resistant to it. This behaviour is similar to that of oxaliplatin against cervical cancer and colon cancer (HT29) cells (oxaliplatin is the number one treatment for colon cancer at present). This compound also proved to be more active against cisplatin resistant cell lines. It was found that all the compounds induced apoptosis in the cell lines tested as well as inhibit the DNA cycle at one or more phase. Finally, an effort was made to evaluate the different compounds by comparing them with respect to their properties relating to anticancer action.
- Full Text:
- Date Issued: 2006
The cost of free instant messaging: an attack modelling perspective
- Authors: Du Preez, Riekert
- Date: 2006
- Subjects: Computer security , Instant messaging , Data protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9797 , http://hdl.handle.net/10948/499 , http://hdl.handle.net/10948/d1011921 , Computer security , Instant messaging , Data protection
- Description: Instant Messaging (IM) has grown tremendously over the last few years. Even though IM was originally developed as a social chat system, it has found a place in many companies, where it is being used as an essential business tool. However, many businesses rely on free IM and have not implemented a secure corporate IM solution. Most free IM clients were never intended for use in the workplace and, therefore, lack strong security features and administrative control. Consequently, free IM clients can provide attackers with an entry point for malicious code in an organization’s network that can ultimately lead to a company’s information assets being compromised. Therefore, even though free IM allows for better collaboration in the workplace, it comes at a cost, as the title of this dissertation suggests. This dissertation sets out to answer the question of how free IM can facilitate an attack on a company’s information assets. To answer the research question, the dissertation defines an IM attack model that models the ways in which an information system can be attacked when free IM is used within an organization. The IM attack model was created by categorising IM threats using the STRIDE threat classification scheme. The attacks that realize the categorised threats were then modelled using attack trees as the chosen attack modelling tool. Attack trees were chosen because of their ability to model the sequence of attacker actions during an attack. The author defined an enhanced graphical notation that was adopted for the attack trees used to create the IM attack model. The enhanced attack tree notation extends traditional attack trees to allow nodes in the trees to be of different classes and, therefore, allows attack trees to convey more information. During the process of defining the IM attack model, a number of experiments were conducted where IM vulnerabilities were exploited. Thereafter, a case study was constructed to document a simulated attack on an information system that involves the exploitation of IM vulnerabilities. The case study demonstrates how an attacker’s attack path relates to the IM attack model in a practical scenario. The IM attack model provides insight into how IM can facilitate an attack on a company’s information assets. The creation of the attack model for free IM lead to several realizations. The IM attack model revealed that even though the use of free IM clients may seem harmless, such IM clients can facilitate an attack on a company’s information assets. Furthermore, certain IM vulnerabilities may not pose a great risk by themselves, but when combined with the exploitation of other vulnerabilities, a much greater threat can be realized. These realizations hold true to what French playwright Jean Anouilh once said: “What you get free costs too much”.
- Full Text:
- Date Issued: 2006
- Authors: Du Preez, Riekert
- Date: 2006
- Subjects: Computer security , Instant messaging , Data protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9797 , http://hdl.handle.net/10948/499 , http://hdl.handle.net/10948/d1011921 , Computer security , Instant messaging , Data protection
- Description: Instant Messaging (IM) has grown tremendously over the last few years. Even though IM was originally developed as a social chat system, it has found a place in many companies, where it is being used as an essential business tool. However, many businesses rely on free IM and have not implemented a secure corporate IM solution. Most free IM clients were never intended for use in the workplace and, therefore, lack strong security features and administrative control. Consequently, free IM clients can provide attackers with an entry point for malicious code in an organization’s network that can ultimately lead to a company’s information assets being compromised. Therefore, even though free IM allows for better collaboration in the workplace, it comes at a cost, as the title of this dissertation suggests. This dissertation sets out to answer the question of how free IM can facilitate an attack on a company’s information assets. To answer the research question, the dissertation defines an IM attack model that models the ways in which an information system can be attacked when free IM is used within an organization. The IM attack model was created by categorising IM threats using the STRIDE threat classification scheme. The attacks that realize the categorised threats were then modelled using attack trees as the chosen attack modelling tool. Attack trees were chosen because of their ability to model the sequence of attacker actions during an attack. The author defined an enhanced graphical notation that was adopted for the attack trees used to create the IM attack model. The enhanced attack tree notation extends traditional attack trees to allow nodes in the trees to be of different classes and, therefore, allows attack trees to convey more information. During the process of defining the IM attack model, a number of experiments were conducted where IM vulnerabilities were exploited. Thereafter, a case study was constructed to document a simulated attack on an information system that involves the exploitation of IM vulnerabilities. The case study demonstrates how an attacker’s attack path relates to the IM attack model in a practical scenario. The IM attack model provides insight into how IM can facilitate an attack on a company’s information assets. The creation of the attack model for free IM lead to several realizations. The IM attack model revealed that even though the use of free IM clients may seem harmless, such IM clients can facilitate an attack on a company’s information assets. Furthermore, certain IM vulnerabilities may not pose a great risk by themselves, but when combined with the exploitation of other vulnerabilities, a much greater threat can be realized. These realizations hold true to what French playwright Jean Anouilh once said: “What you get free costs too much”.
- Full Text:
- Date Issued: 2006