Using the tutorial system to improve the quality of feedback to students in large class teaching
- Snowball, Jeanette D, Sayigh, Elizabeth
- Authors: Snowball, Jeanette D , Sayigh, Elizabeth
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70848 , vital:29752
- Description: In many universities, economics teachers now face the challenge of dealing with large, diverse classes, especially at undergraduate level. A common concern is the non-attendance at lectures of unmotivated (conscript) students. This paper presents the results of a student assessment of a macroeconomics 1 course, coupled with a self-assessment of their own input into the course. The results obtained, using an econometric model, suggest that what students do outside of lectures is equally, or more, important than lecture attendance itself. The paper concludes by examining the possibility of using peer assessed group learning as a feasible way to encourage deep learning in large classes.
- Full Text:
- Date Issued: 2007
- Authors: Snowball, Jeanette D , Sayigh, Elizabeth
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70848 , vital:29752
- Description: In many universities, economics teachers now face the challenge of dealing with large, diverse classes, especially at undergraduate level. A common concern is the non-attendance at lectures of unmotivated (conscript) students. This paper presents the results of a student assessment of a macroeconomics 1 course, coupled with a self-assessment of their own input into the course. The results obtained, using an econometric model, suggest that what students do outside of lectures is equally, or more, important than lecture attendance itself. The paper concludes by examining the possibility of using peer assessed group learning as a feasible way to encourage deep learning in large classes.
- Full Text:
- Date Issued: 2007
Valuing preferences for freshwater inflows into the Bira, Bushmans, Kasouga, Keiskamma, Kleinemond East, Nahoon and Tyolomnqa estuaries
- Authors: Van der Westhuizen, Henri
- Date: 2007
- Subjects: Estuarine ecology -- South Africa -- Eastern Cape , Freshwater ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8998 , http://hdl.handle.net/10948/628 , Estuarine ecology -- South Africa -- Eastern Cape , Freshwater ecology -- South Africa -- Eastern Cape
- Description: There are about 259 estuaries in South Africa that can be classified as “functioning” and their “health” status is directly related to the quantity and quality of freshwater that flows into them. Many of South Africa’s estuaries have become smaller due to a steady decrease in the amount of freshwater that flows into them. This reduction in freshwater inflows decreases their ecological functioning and undermines the recreational activities and subsistence services available from them. The National Water Act (ACT No. 36 of 1998) recognises the right of the environment to water, but a large amount of data is still needed to make management decisions on the allocation of freshwater. The objective of this research was to contribute to the management of the allocation of freshwater in the catchment areas of the Bira, Bushmans, Kasouga, Keiskamma, Kleinemond East, Nahoon and Tyolomnqa rivers by determining the recreational value of the freshwater flowing into their estuaries. This recreational value was established using the contingent valuation method. The contingent valuation method (CVM) is a technique to establish the value of a good (or service) that is not bought or sold in an actual market. This technique is frequently applied in the valuation of environmental goods, e.g. the freshwater that flows into an estuary. The CVM establishes the economic value by asking the users of an environmental good to state their willingness to pay (WTP) for a hypothetical project to prevent or bring about a change in the current condition of the environmental good. The users’ WTP is then aggregated to establish a total willingness to pay (TWTP) for the population of the users of the environmental good. The hypothetical project presented in this study is that of an increase of freshwater inflows, that would prevent (bring about) predetermined changes in environmental services provided by the selected seven estuaries.
- Full Text:
- Date Issued: 2007
- Authors: Van der Westhuizen, Henri
- Date: 2007
- Subjects: Estuarine ecology -- South Africa -- Eastern Cape , Freshwater ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8998 , http://hdl.handle.net/10948/628 , Estuarine ecology -- South Africa -- Eastern Cape , Freshwater ecology -- South Africa -- Eastern Cape
- Description: There are about 259 estuaries in South Africa that can be classified as “functioning” and their “health” status is directly related to the quantity and quality of freshwater that flows into them. Many of South Africa’s estuaries have become smaller due to a steady decrease in the amount of freshwater that flows into them. This reduction in freshwater inflows decreases their ecological functioning and undermines the recreational activities and subsistence services available from them. The National Water Act (ACT No. 36 of 1998) recognises the right of the environment to water, but a large amount of data is still needed to make management decisions on the allocation of freshwater. The objective of this research was to contribute to the management of the allocation of freshwater in the catchment areas of the Bira, Bushmans, Kasouga, Keiskamma, Kleinemond East, Nahoon and Tyolomnqa rivers by determining the recreational value of the freshwater flowing into their estuaries. This recreational value was established using the contingent valuation method. The contingent valuation method (CVM) is a technique to establish the value of a good (or service) that is not bought or sold in an actual market. This technique is frequently applied in the valuation of environmental goods, e.g. the freshwater that flows into an estuary. The CVM establishes the economic value by asking the users of an environmental good to state their willingness to pay (WTP) for a hypothetical project to prevent or bring about a change in the current condition of the environmental good. The users’ WTP is then aggregated to establish a total willingness to pay (TWTP) for the population of the users of the environmental good. The hypothetical project presented in this study is that of an increase of freshwater inflows, that would prevent (bring about) predetermined changes in environmental services provided by the selected seven estuaries.
- Full Text:
- Date Issued: 2007
Vicarious and direct liability of an employer for sexual harassment at work
- Authors: Lawlor, Ryan Mark
- Date: 2007
- Subjects: Sexual harassment -- Law and legislation -- South Africa , Sex discrimination in employment -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10266 , http://hdl.handle.net/10948/825 , Sexual harassment -- Law and legislation -- South Africa , Sex discrimination in employment -- Law and legislation -- South Africa
- Description: Sexual harassment is an ever increasing drain on the resources of the modern employer, as well as serving to take up much time in terms of legal battles and court cases. The concept of sexual harassment has undergone much revision over the past decades, and South Africa is now firmly committed to the eradication of this problem. The Constitution protects and enshrines important rights like dignity, equality and the right to fair labour practices. These are further defined and protected through the application of various statutes, including the LRA, EEA, PEPUDA and the revised Code of Good Practice. In terms of statutory liability, the employer will be liable for the harassment of its employees, unless it takes a proactive stance and implements comprehensive sexual harassment policies. In this way it will escape liability. The common law vicarious liability of the employer cannot be escaped as easily. The entire concept of the law of delict is to remedy harm suffered. In terms of the common law, employers will be held vicariously liable for the harassment of their employees if it can be shown that the harassment occurred within a valid working relationship, if the harassment actually occurred through a delict, and if the act occurred within the course and scope of employment. The best way for employers to minimize their liability for sexual harassment is the implementation of training and educational policies that serve to make employees aware of what is permissible in the workplace. This will aid the employer in showing that it has done everything possible to reduce the risk of harassment, which will in turn serve to reduce the employer’s liability. To protect against the risk of expensive litigation, many employers are now investigating the matter of liability insurance – they would rather pay increased premiums than suffer alone when their employees take legal action against them. Sexual harassment is a problem that can only be solved through a concerted effort on the part of the legislature, judiciary, employers and employees. Together, these parties must ensure that all of those involved in the world of work are aware of the problem of harassment, as well as taking steps to educate and train employees so as to prevent it. Only in this way will we be able to take action to reduce this terrible problem in our country.
- Full Text:
- Date Issued: 2007
- Authors: Lawlor, Ryan Mark
- Date: 2007
- Subjects: Sexual harassment -- Law and legislation -- South Africa , Sex discrimination in employment -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10266 , http://hdl.handle.net/10948/825 , Sexual harassment -- Law and legislation -- South Africa , Sex discrimination in employment -- Law and legislation -- South Africa
- Description: Sexual harassment is an ever increasing drain on the resources of the modern employer, as well as serving to take up much time in terms of legal battles and court cases. The concept of sexual harassment has undergone much revision over the past decades, and South Africa is now firmly committed to the eradication of this problem. The Constitution protects and enshrines important rights like dignity, equality and the right to fair labour practices. These are further defined and protected through the application of various statutes, including the LRA, EEA, PEPUDA and the revised Code of Good Practice. In terms of statutory liability, the employer will be liable for the harassment of its employees, unless it takes a proactive stance and implements comprehensive sexual harassment policies. In this way it will escape liability. The common law vicarious liability of the employer cannot be escaped as easily. The entire concept of the law of delict is to remedy harm suffered. In terms of the common law, employers will be held vicariously liable for the harassment of their employees if it can be shown that the harassment occurred within a valid working relationship, if the harassment actually occurred through a delict, and if the act occurred within the course and scope of employment. The best way for employers to minimize their liability for sexual harassment is the implementation of training and educational policies that serve to make employees aware of what is permissible in the workplace. This will aid the employer in showing that it has done everything possible to reduce the risk of harassment, which will in turn serve to reduce the employer’s liability. To protect against the risk of expensive litigation, many employers are now investigating the matter of liability insurance – they would rather pay increased premiums than suffer alone when their employees take legal action against them. Sexual harassment is a problem that can only be solved through a concerted effort on the part of the legislature, judiciary, employers and employees. Together, these parties must ensure that all of those involved in the world of work are aware of the problem of harassment, as well as taking steps to educate and train employees so as to prevent it. Only in this way will we be able to take action to reduce this terrible problem in our country.
- Full Text:
- Date Issued: 2007
Vice Chancellor New staff welcome address, 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Type: text
- Identifier: vital:7646 , http://hdl.handle.net/10962/d1015774
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Type: text
- Identifier: vital:7646 , http://hdl.handle.net/10962/d1015774
- Full Text:
- Date Issued: 2007
Vice Chancellor's message to the Toronto Old Rhodian Reunion
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7648 , http://hdl.handle.net/10962/d1015776
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7648 , http://hdl.handle.net/10962/d1015776
- Full Text:
- Date Issued: 2007
Vice Chancellor's Oppidan Newspaper message, 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7649 , http://hdl.handle.net/10962/d1015777
- Full Text:
- Date Issued: 2007
- Authors: Badat, Saleem
- Date: 2007
- Subjects: Rhodes University
- Language: English
- Type: text
- Identifier: vital:7649 , http://hdl.handle.net/10962/d1015777
- Full Text:
- Date Issued: 2007
Voltammetric characterisation of the self-assembled monolayers (SAMs) of benzyl-and dodecyl-mercapto tetra substituted metallophthalocyanines complexes
- Agboola, Bolade, Westbroek, Philippe, Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Agboola, Bolade , Westbroek, Philippe , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281414 , vital:55723 , xlink:href="https://doi.org/10.1016/j.elecom.2006.08.047"
- Description: Voltammetric characterisations of cobalt, iron, manganese, nickel and zinc phthalocyanine complexes tetra substituted with benzyl- and dodecyl-mercapto ring substituents and immobilisation on gold electrodes via the self-assembling technique are presented. The self-assembled films are stable and showed blocking characteristics towards the following Faradaic processes; gold surface oxidation, under potential deposition of copper and solution redox chemistry of [Fe(H2O)6 3+ ]/[Fe(H2O)6 2+ ]. The solution chemistry of [Fe(CN)6]−3/[Fe(CN)6]−4 redox process was used to study the orientation of the CoPcs-SAMs and this revealed a possible deviation from flat orientation of the complexes on the gold electrodes when the SAM formation times were greater than 24 h. For SAM formation time at 24 and 48 h, CoTDMPc-SAM showed more inhibition of the [Fe(CN)6]−3/[Fe(CN)6]−4 redox process than the CoTBMPc-SAM counterpart, indicating more blocking characteristics of the dodecylmercapto ring substituents compared to the benzylmercapto counterpart. To avoid SAM desorption, the potential application should be limited to −0.2 to +0.8 V vs. Ag∣AgCl (NaCl, sat’d) in acidic and neutral pH.
- Full Text:
- Date Issued: 2007
- Authors: Agboola, Bolade , Westbroek, Philippe , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281414 , vital:55723 , xlink:href="https://doi.org/10.1016/j.elecom.2006.08.047"
- Description: Voltammetric characterisations of cobalt, iron, manganese, nickel and zinc phthalocyanine complexes tetra substituted with benzyl- and dodecyl-mercapto ring substituents and immobilisation on gold electrodes via the self-assembling technique are presented. The self-assembled films are stable and showed blocking characteristics towards the following Faradaic processes; gold surface oxidation, under potential deposition of copper and solution redox chemistry of [Fe(H2O)6 3+ ]/[Fe(H2O)6 2+ ]. The solution chemistry of [Fe(CN)6]−3/[Fe(CN)6]−4 redox process was used to study the orientation of the CoPcs-SAMs and this revealed a possible deviation from flat orientation of the complexes on the gold electrodes when the SAM formation times were greater than 24 h. For SAM formation time at 24 and 48 h, CoTDMPc-SAM showed more inhibition of the [Fe(CN)6]−3/[Fe(CN)6]−4 redox process than the CoTBMPc-SAM counterpart, indicating more blocking characteristics of the dodecylmercapto ring substituents compared to the benzylmercapto counterpart. To avoid SAM desorption, the potential application should be limited to −0.2 to +0.8 V vs. Ag∣AgCl (NaCl, sat’d) in acidic and neutral pH.
- Full Text:
- Date Issued: 2007
Wave exposure effects on population structure and recruitment in the mussel Perna perna suggest regulation primarily through availability of recruits and food, not space
- McQuaid, Christopher D, Lindsay, Tracy L
- Authors: McQuaid, Christopher D , Lindsay, Tracy L
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6968 , http://hdl.handle.net/10962/d1012033
- Description: Recruitment and population structure of Perna perna in low shore mussel beds were investigated over 15 months at six sites along the south coast of South Africa. Initial, subjective classification of sites as wave exposed or wave sheltered (three of each) was confirmed using the dissolution of cement blocks to measure average water flux and dynamometers for maximum wave force. Recruitment occurred throughout the year, but recruit (1–5 mm) densities were significantly higher from January to April 1996 on both shore types. Recruit densities were positively correlated with adult (>15 mm) densities for both shore types (P < 0.05) but the correlations were extremely weak (r 2 < 0.06 in each case). In areas with 100% cover, adult size (mean and maximum lengths) was greater on exposed sites, but density showed the reverse and was negatively correlated with maximum wave strength (r = −0.84). Despite differences in adult densities and sizes, biomass, which is a product of the two, showed no significant difference between the two shore types (ANOVA P > 0.05). Thus wave exposure dramatically affects density, recruitment and mussel size, but not recruitment timing or biomass where there is 100% cover, and mediates a three-way interaction among food supply, larval supply and intraspecific competition for space. In contrast to shores with saturation recruitment, mussel biomass here appears to be limited by recruit supply and constraints of food, especially on sheltered shores, while density is regulated through intraspecific competition for space primarily on exposed shores and at small spatial scales.
- Full Text:
- Date Issued: 2007
- Authors: McQuaid, Christopher D , Lindsay, Tracy L
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6968 , http://hdl.handle.net/10962/d1012033
- Description: Recruitment and population structure of Perna perna in low shore mussel beds were investigated over 15 months at six sites along the south coast of South Africa. Initial, subjective classification of sites as wave exposed or wave sheltered (three of each) was confirmed using the dissolution of cement blocks to measure average water flux and dynamometers for maximum wave force. Recruitment occurred throughout the year, but recruit (1–5 mm) densities were significantly higher from January to April 1996 on both shore types. Recruit densities were positively correlated with adult (>15 mm) densities for both shore types (P < 0.05) but the correlations were extremely weak (r 2 < 0.06 in each case). In areas with 100% cover, adult size (mean and maximum lengths) was greater on exposed sites, but density showed the reverse and was negatively correlated with maximum wave strength (r = −0.84). Despite differences in adult densities and sizes, biomass, which is a product of the two, showed no significant difference between the two shore types (ANOVA P > 0.05). Thus wave exposure dramatically affects density, recruitment and mussel size, but not recruitment timing or biomass where there is 100% cover, and mediates a three-way interaction among food supply, larval supply and intraspecific competition for space. In contrast to shores with saturation recruitment, mussel biomass here appears to be limited by recruit supply and constraints of food, especially on sheltered shores, while density is regulated through intraspecific competition for space primarily on exposed shores and at small spatial scales.
- Full Text:
- Date Issued: 2007
WET-Roadmap:
- Dada, Rehana, Kotze, Donovan C, Ellery, William F N, Uys, Mary, Breen, Charles, Dini, John, Mitchell, Steve
- Authors: Dada, Rehana , Kotze, Donovan C , Ellery, William F N , Uys, Mary , Breen, Charles , Dini, John , Mitchell, Steve
- Date: 2007
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/176596 , vital:40093 , ISBN 978-1-77005-632-9 , http://www.wrc.org.za/wp-content/uploads/mdocs/TT 321-07.pdf
- Description: The WET-Management Series is a set of integrated tools that can be used to guide well-informed and effective wetland management and rehabilitation. Wetland loss in South Africa has been significant and the need for wetland rehabilitation as part of good wetland stewardship and management is compelling. National policy and legislation provide clear direction and support for rehabilitation, but the very complex links between people and wetlands mean that actions aimed at sustainably rehabilitating and conserving wetlands will depend on the dedication and commitment of all stakeholders, especially landowners and wetland users.
- Full Text:
- Date Issued: 2007
- Authors: Dada, Rehana , Kotze, Donovan C , Ellery, William F N , Uys, Mary , Breen, Charles , Dini, John , Mitchell, Steve
- Date: 2007
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/176596 , vital:40093 , ISBN 978-1-77005-632-9 , http://www.wrc.org.za/wp-content/uploads/mdocs/TT 321-07.pdf
- Description: The WET-Management Series is a set of integrated tools that can be used to guide well-informed and effective wetland management and rehabilitation. Wetland loss in South Africa has been significant and the need for wetland rehabilitation as part of good wetland stewardship and management is compelling. National policy and legislation provide clear direction and support for rehabilitation, but the very complex links between people and wetlands mean that actions aimed at sustainably rehabilitating and conserving wetlands will depend on the dedication and commitment of all stakeholders, especially landowners and wetland users.
- Full Text:
- Date Issued: 2007
Wheat stress responses during Russian wheat aphid and Bird Cherry Oat aphid infestation: an analysis of differential protein regulation during plant biotic stress responses
- Louw, Cassandra Alexandrovna
- Authors: Louw, Cassandra Alexandrovna
- Date: 2007
- Subjects: Russian wheat aphid , Plants, Effect of stress on , Wheat -- Diseases and pests , Rhopalosiphum , Plant proteins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3995 , http://hdl.handle.net/10962/d1004055 , Russian wheat aphid , Plants, Effect of stress on , Wheat -- Diseases and pests , Rhopalosiphum , Plant proteins
- Description: Plants possess a complex and poorly understood network of defence mechanisms that enable them to counteract the effects of abiotic and biotic stress. Aphid phloem feeding is source of biotic stress in plants. Russian wheat aphid and Bird Cherry-Oat aphid feeding cause significant losses in the annual wheat crop, and control by conventional methods such as pesticide application, has proved to be ineffective. Infestation by the Russian wheat aphid has a particularly devastating effect in South Africa. Aphid-resistant wheat cultivars have been identified but an incomplete understanding of the mechanism of the plant’s resistance thwarts the development of improved cultivars. A two-dimensional gel electrophoresis method was developed, partially optimised and validated in order to determine the effect of Russian wheat aphid and Bird Cherry-Oat aphid phloem feeding on the Betta and Betta DN wheat proteome. Differentially expressed proteins that were up or down regulated more than two fold were identified using PDQuest™ Basic software and matched to known wheat proteins stored in the SwissProt protein database on the basis of their molecular mass and isolectric point. Initial analysis of the differential protein expression of Betta and Betta DN wheat in response to Russian wheat aphid and Bird Cherry-Oat aphid phloem feeding at different growth stages revealed that younger plants display higher levels of resistance than older plants. Feeding by the Bird-Cherry Oat aphid does not result in the upregulation of proteins implicated in a defence response, which indicates that the damage incurred by the plant due to feeding by this aphid is not enough to trigger a classic defence response. Feeding by the more damaging Russian wheat aphid resulted in a stress response in susceptible wheat cultivar Betta, and a defence response in resistant wheat cultivar Betta DN. The infestation of Betta DN resulted in the upregulation of putative thaumatins and amylase trypsin inhibitors, indicating that the Betta DN resistance response could be due to the combined effect of protease inhibitors that discourage aphid phloem feeding and the activation of the salicylic acid and jasmonic acid plant defence pathways.
- Full Text:
- Date Issued: 2007
- Authors: Louw, Cassandra Alexandrovna
- Date: 2007
- Subjects: Russian wheat aphid , Plants, Effect of stress on , Wheat -- Diseases and pests , Rhopalosiphum , Plant proteins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3995 , http://hdl.handle.net/10962/d1004055 , Russian wheat aphid , Plants, Effect of stress on , Wheat -- Diseases and pests , Rhopalosiphum , Plant proteins
- Description: Plants possess a complex and poorly understood network of defence mechanisms that enable them to counteract the effects of abiotic and biotic stress. Aphid phloem feeding is source of biotic stress in plants. Russian wheat aphid and Bird Cherry-Oat aphid feeding cause significant losses in the annual wheat crop, and control by conventional methods such as pesticide application, has proved to be ineffective. Infestation by the Russian wheat aphid has a particularly devastating effect in South Africa. Aphid-resistant wheat cultivars have been identified but an incomplete understanding of the mechanism of the plant’s resistance thwarts the development of improved cultivars. A two-dimensional gel electrophoresis method was developed, partially optimised and validated in order to determine the effect of Russian wheat aphid and Bird Cherry-Oat aphid phloem feeding on the Betta and Betta DN wheat proteome. Differentially expressed proteins that were up or down regulated more than two fold were identified using PDQuest™ Basic software and matched to known wheat proteins stored in the SwissProt protein database on the basis of their molecular mass and isolectric point. Initial analysis of the differential protein expression of Betta and Betta DN wheat in response to Russian wheat aphid and Bird Cherry-Oat aphid phloem feeding at different growth stages revealed that younger plants display higher levels of resistance than older plants. Feeding by the Bird-Cherry Oat aphid does not result in the upregulation of proteins implicated in a defence response, which indicates that the damage incurred by the plant due to feeding by this aphid is not enough to trigger a classic defence response. Feeding by the more damaging Russian wheat aphid resulted in a stress response in susceptible wheat cultivar Betta, and a defence response in resistant wheat cultivar Betta DN. The infestation of Betta DN resulted in the upregulation of putative thaumatins and amylase trypsin inhibitors, indicating that the Betta DN resistance response could be due to the combined effect of protease inhibitors that discourage aphid phloem feeding and the activation of the salicylic acid and jasmonic acid plant defence pathways.
- Full Text:
- Date Issued: 2007
Wi-Fi as a last mile access technology and The Tragedy of the Commons
- Brandt, Ingrid, Terzoli, Alfredo, Hodgkinson-Williams, Cheryl
- Authors: Brandt, Ingrid , Terzoli, Alfredo , Hodgkinson-Williams, Cheryl
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431106 , vital:72744 , https://doi.org/10.1007/978-1-4020-6266-7_33
- Description: With an alarmingly low teledensity in South Africa, just 12%, and not much hope of further wired infrastructure at the local loop level, as the costs incurred are high compared to potential revenue, wireless con-nectivity could be a great asset and service in South Africa. However, the use of unlicensed spectrum in building wireless networks can be comparable to “The Tragedy of the Commons”, the result of selfish be-haviour towards common and limited resources. This paper evaluates the use of 802.11 wireless technologies in building a broadband wire-less network and the effects of high amounts of interference on such a network. The paper concludes that for urban areas 802.11 technologies using unlicensed spectrum is not advisable, unless used in point-to-point links, while its use in rapid rural development (where there is less interference) is very promising.
- Full Text:
- Date Issued: 2007
- Authors: Brandt, Ingrid , Terzoli, Alfredo , Hodgkinson-Williams, Cheryl
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431106 , vital:72744 , https://doi.org/10.1007/978-1-4020-6266-7_33
- Description: With an alarmingly low teledensity in South Africa, just 12%, and not much hope of further wired infrastructure at the local loop level, as the costs incurred are high compared to potential revenue, wireless con-nectivity could be a great asset and service in South Africa. However, the use of unlicensed spectrum in building wireless networks can be comparable to “The Tragedy of the Commons”, the result of selfish be-haviour towards common and limited resources. This paper evaluates the use of 802.11 wireless technologies in building a broadband wire-less network and the effects of high amounts of interference on such a network. The paper concludes that for urban areas 802.11 technologies using unlicensed spectrum is not advisable, unless used in point-to-point links, while its use in rapid rural development (where there is less interference) is very promising.
- Full Text:
- Date Issued: 2007
Women living with HIV/AIDS: a phenomenological intergenerational interpretation of their experiences
- Chisaka, Janet Kaemba Chishimba
- Authors: Chisaka, Janet Kaemba Chishimba
- Date: 2007
- Subjects: AIDS (Disease) in women -- South Africa -- Case studies HIV positive women -- South Africa -- Case studies Poor women -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3307 , http://hdl.handle.net/10962/d1003095
- Description: This study deals with the impact of HIV/AIDS on women living in chronic poverty. The question arises: Do we focus on their HIV/AIDS stories only or do we include their other lived experiences? This phenomenological study, on two sets of three generations of women infected and affected by HIV/AIDS and living in poverty, is an attempt at understanding the way the women experience their lifeworlds, not only their HIV/AIDS stories. One set includes a grandmother, her daughter who is living with full-blown AIDS, and her granddaughter, while the other includes a grandmother, her daughter and her granddaughter infected with HIV. The initial focus of the study was on the women’s HIV/AIDS narratives. However as the study progressed, especially during the interviews, it became apparent that the women’s generational poverty or chronic poverty was of greater concern to them than the HIV/AIDS that they were experiencing. Of the six participants, only one woman centred her life story on HIV/AIDS. This finding echoes other studies on HIV/AIDS among poor women: that chronic poverty is more threatening to the women than the risk or reality of AIDS. As a phenomenological researcher my aim was to focus on the participants’ own interpretations of the studied phenomenon. However, this was inadequate in accounting for the role that social structures play in shaping and informing the women’s subjective consciousness and experience. For this reason, I used feminist ideas to understand and interpret the women’s patriarchal experiences.
- Full Text:
- Date Issued: 2007
Women living with HIV/AIDS: a phenomenological intergenerational interpretation of their experiences
- Authors: Chisaka, Janet Kaemba Chishimba
- Date: 2007
- Subjects: AIDS (Disease) in women -- South Africa -- Case studies HIV positive women -- South Africa -- Case studies Poor women -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3307 , http://hdl.handle.net/10962/d1003095
- Description: This study deals with the impact of HIV/AIDS on women living in chronic poverty. The question arises: Do we focus on their HIV/AIDS stories only or do we include their other lived experiences? This phenomenological study, on two sets of three generations of women infected and affected by HIV/AIDS and living in poverty, is an attempt at understanding the way the women experience their lifeworlds, not only their HIV/AIDS stories. One set includes a grandmother, her daughter who is living with full-blown AIDS, and her granddaughter, while the other includes a grandmother, her daughter and her granddaughter infected with HIV. The initial focus of the study was on the women’s HIV/AIDS narratives. However as the study progressed, especially during the interviews, it became apparent that the women’s generational poverty or chronic poverty was of greater concern to them than the HIV/AIDS that they were experiencing. Of the six participants, only one woman centred her life story on HIV/AIDS. This finding echoes other studies on HIV/AIDS among poor women: that chronic poverty is more threatening to the women than the risk or reality of AIDS. As a phenomenological researcher my aim was to focus on the participants’ own interpretations of the studied phenomenon. However, this was inadequate in accounting for the role that social structures play in shaping and informing the women’s subjective consciousness and experience. For this reason, I used feminist ideas to understand and interpret the women’s patriarchal experiences.
- Full Text:
- Date Issued: 2007
Women's perceptions and experiences of antenatal care rendered by midwives
- Authors: Mxoli, Winnifred Nonkonzo
- Date: 2007
- Subjects: Prenatal care -- South Africa -- Eastern Cape , Midwives -- South Africa -- Eastern Cape , Maternal health services -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: vital:10041 , http://hdl.handle.net/10948/575 , Prenatal care -- South Africa -- Eastern Cape , Midwives -- South Africa -- Eastern Cape , Maternal health services -- South Africa -- Eastern Cape
- Description: The general health status of pregnant women depends largely on the quality of the antenatal services available to them. The provision of good antenatal services ensures early detection and prompt management of any complication or disease that may adversely affect pregnancy outcome. In order to ensure high quality care, antenatal services need to be evaluated at regular intervals, both from provider and client perspective, to ensure their effectiveness in improving the health status of pregnant women. The midwife, as the first contact person for most pregnant women attending antenatal clinics in South Africa, has the potential to play a major role in improving the health status of these women. However, for the midwife to be effective in achieving this, antenatal services need to be effectively utilized by women. One of the factors that affect utilization of any service is client satisfaction with the service being rendered. This study, therefore, explores the perceptions that pregnant women have of the care that they receive from midwives at the selected antenatal clinics. The objectives of the study are to: {u100083} Explore and describe the perceptions and experiences of pregnant women attending antenatal clinic regarding the care they receive from midwives. {u100083} Make recommendations to assist registered midwives in optimizing the accompaniment of women during the antenatal period. A qualitative, descriptive, exploratory and contextual design was used for the study. The sample was chosen from the target population by means of purposive sampling and data was collected through unstructured interviews with the participants. Before data collection, permission was obtained from the Eastern Cape Department of Health and the Nursing Service Manager of the Gateway clinic, in the district hospital where the research was conducted. The Nursing Service Manager was acting as a Medical Superintendent at the time of the study. Written, informed consent was obtained from all participants before conducting interviews. Trustworthiness was ensured by means of Guba’s model throughout the study, and the aspects of truth value, applicability, consistency and neutrality were considered. Tesch’s eight steps of data analysis were used to analyze the data collected, and four main themes were identified namely: • Women perceive midwives as considerate and knowledgeable • Women perceive midwives as lazy and rude • Women experience mixed emotions about the care they receive from midwives • Though their experiences, women identified certain needs in the services and care they received at the clinic. Conclusions were drawn and recommendations for midwifery practice made based on the results of the study, with the aim of improving antenatal services rendered to pregnant women.
- Full Text:
- Date Issued: 2007
- Authors: Mxoli, Winnifred Nonkonzo
- Date: 2007
- Subjects: Prenatal care -- South Africa -- Eastern Cape , Midwives -- South Africa -- Eastern Cape , Maternal health services -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: vital:10041 , http://hdl.handle.net/10948/575 , Prenatal care -- South Africa -- Eastern Cape , Midwives -- South Africa -- Eastern Cape , Maternal health services -- South Africa -- Eastern Cape
- Description: The general health status of pregnant women depends largely on the quality of the antenatal services available to them. The provision of good antenatal services ensures early detection and prompt management of any complication or disease that may adversely affect pregnancy outcome. In order to ensure high quality care, antenatal services need to be evaluated at regular intervals, both from provider and client perspective, to ensure their effectiveness in improving the health status of pregnant women. The midwife, as the first contact person for most pregnant women attending antenatal clinics in South Africa, has the potential to play a major role in improving the health status of these women. However, for the midwife to be effective in achieving this, antenatal services need to be effectively utilized by women. One of the factors that affect utilization of any service is client satisfaction with the service being rendered. This study, therefore, explores the perceptions that pregnant women have of the care that they receive from midwives at the selected antenatal clinics. The objectives of the study are to: {u100083} Explore and describe the perceptions and experiences of pregnant women attending antenatal clinic regarding the care they receive from midwives. {u100083} Make recommendations to assist registered midwives in optimizing the accompaniment of women during the antenatal period. A qualitative, descriptive, exploratory and contextual design was used for the study. The sample was chosen from the target population by means of purposive sampling and data was collected through unstructured interviews with the participants. Before data collection, permission was obtained from the Eastern Cape Department of Health and the Nursing Service Manager of the Gateway clinic, in the district hospital where the research was conducted. The Nursing Service Manager was acting as a Medical Superintendent at the time of the study. Written, informed consent was obtained from all participants before conducting interviews. Trustworthiness was ensured by means of Guba’s model throughout the study, and the aspects of truth value, applicability, consistency and neutrality were considered. Tesch’s eight steps of data analysis were used to analyze the data collected, and four main themes were identified namely: • Women perceive midwives as considerate and knowledgeable • Women perceive midwives as lazy and rude • Women experience mixed emotions about the care they receive from midwives • Though their experiences, women identified certain needs in the services and care they received at the clinic. Conclusions were drawn and recommendations for midwifery practice made based on the results of the study, with the aim of improving antenatal services rendered to pregnant women.
- Full Text:
- Date Issued: 2007
Working in the city: the design of a vehicle technology research centre for Volkswagen SA in the Nelson Mandela Metropole
- Authors: Danev, Anton V
- Date: 2007
- Subjects: Volkswagen of South Africa (Firm) , Research institutes -- South Africa -- Port Elizabeth -- Designs and plans , Motor vehicle industry -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , M.Arcitecture
- Identifier: http://hdl.handle.net/10948/52834 , vital:44235
- Description: Volkswagen AG is the second largest vehicle manufacturer worldwide with a factory plant located in the Nelson Mandela Metropole. Major part of their [technological] research has in the last 10 years shifted towards a sustainability outlook along a environmentally friendly end-user products approach. A great market is emerging where environmentally sensitive vehicles and equipment are at the forefront of technological development. Volkswagen currently has a limited number of Vehicle Technology Research facilities worldwide and is looking to establish firm positions locally, in line with its company ethics of sustainability and energy consciousness. Part of this initiative is to locate into the CBD of Port Elizabeth aiming to revitalise derelict [inner-city] urban space and promote environmentally sensitive development. Consequently this thesis seeks to explore the possibility of introducing a ( technology) research facility and office space, as part of a mixed-use development, into Port Elizabeth’s inner city and investigate the architectural challenges thereof.
- Full Text:
- Date Issued: 2007
- Authors: Danev, Anton V
- Date: 2007
- Subjects: Volkswagen of South Africa (Firm) , Research institutes -- South Africa -- Port Elizabeth -- Designs and plans , Motor vehicle industry -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , M.Arcitecture
- Identifier: http://hdl.handle.net/10948/52834 , vital:44235
- Description: Volkswagen AG is the second largest vehicle manufacturer worldwide with a factory plant located in the Nelson Mandela Metropole. Major part of their [technological] research has in the last 10 years shifted towards a sustainability outlook along a environmentally friendly end-user products approach. A great market is emerging where environmentally sensitive vehicles and equipment are at the forefront of technological development. Volkswagen currently has a limited number of Vehicle Technology Research facilities worldwide and is looking to establish firm positions locally, in line with its company ethics of sustainability and energy consciousness. Part of this initiative is to locate into the CBD of Port Elizabeth aiming to revitalise derelict [inner-city] urban space and promote environmentally sensitive development. Consequently this thesis seeks to explore the possibility of introducing a ( technology) research facility and office space, as part of a mixed-use development, into Port Elizabeth’s inner city and investigate the architectural challenges thereof.
- Full Text:
- Date Issued: 2007
Workplace forums in terms of the labour relations act 66 of 1995
- Authors: Pather, Sivalingam
- Date: 2007
- Subjects: Industrial relations -- South Africa , Labor laws and legislation -- South Africa , Works councils -- Law and legislation -- South Africa , Works councils -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10229 , http://hdl.handle.net/10948/845 , Industrial relations -- South Africa , Labor laws and legislation -- South Africa , Works councils -- Law and legislation -- South Africa , Works councils -- South Africa
- Description: The promulgation into law of the concept of workplace forums has been beset with immense criticism and opposition from organized labour and some quarters of organized business. Last ditch efforts by the Ministerial Task Team had won the day for the inclusion of this controversial provision in the new Labour Relations Act.1 Commentators on the Act tend to agree that the fallout with organized labour at the negotiations has probably set the scene as to whether the provisions would be widely used or not. History has shown that the establishment of such forums in workplaces has been low. In some situations where workplace forums had been established, their continuous sustainability was put into doubt. This has led to the de-establishment of some of these forums in some workplaces. Various reasons were provided, but the prime factors for its failure could be traced back to the negotiations at NEDLAC. The unions opposed the original proposal by government that minority unions and even non-union employees can trigger the establishment of a workplace forum and insisted that this be restricted to majority unions. The voluntary nature regarding the establishment of a workplace forum and the trigger that only a majority union can invoke the provisions has still seen unions reluctant to utilize the provisions since it did not serve their purpose. The aims of the provisions, namely to increase workplace democracy, was therefore thwarted in favour of more informal procedures. Although the idea is a noble one, it is argued that the introduction of the provisions was ill-timed and inappropriate. The lesson that the legislature can take is that for any provision to be a success, buy-in from all stakeholders is paramount. Research has shown that there was a steady decline in the establishment of workplace forums. Since December 2004 there was not a single application received by the Commission for Conciliation, mediation and Arbitration. There is also doubt as to whether any of the Forums that were previously established are still functional. What is certain is that statutory workplace forums is not at the forefront as a vehicle for change that was envisaged in the Explanatory Memorandum that accompanied the new Labour Relations Act. What is also certain is that employers and employees are utilizing other forums to ensure workplace participation. These forums, however, only provide a voice to unionized workers. The vast majority of non-union workers remain voiceless. The proposed amendments in 2002 that intimated that the trigger be any union and not only majority unions failed to be passed into law. Perhaps it is that type of catalyst that is required to give life to the provisions. The future of workplace forums in South Africa is bleak and will continue to be if there is no intervention by the parties at NEDLAC to revive it. A complete revamp of the legislation would be required for such a revival. Some commentators have made meaningful suggestions on changes that can be made to the legislation to make workplace forums more attractive. Some have suggested it be scrapped altogether and future workplace participatory structures should be left to the parties to embrace voluntarily. Workplace forums are a novel innovation with great potential to encourage workplace democracy. There is nothing wrong with the concept. The application of such forums in the South African context is what is concerning. Perhaps prior experience and experimentation with similar type forums have tarnished workplace participation. The strategies by the previous regime and some employers have caused such participation to equate to co-option. Perhaps not enough spade work was done to ensure that the climate and attitude of the parties was conducive for its introduction. What is paramount no matter the form it takes is that workplace participation is crucial for economic growth and the introduction of new work methods to improve productivity. Without the establishment of such forums, whether voluntary or statutory, the ‘second channel principle’ that promotes non-adversarial workplace joint decision-making would be lost and conflict based participation could spiral leading to economic disaster.
- Full Text:
- Date Issued: 2007
- Authors: Pather, Sivalingam
- Date: 2007
- Subjects: Industrial relations -- South Africa , Labor laws and legislation -- South Africa , Works councils -- Law and legislation -- South Africa , Works councils -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10229 , http://hdl.handle.net/10948/845 , Industrial relations -- South Africa , Labor laws and legislation -- South Africa , Works councils -- Law and legislation -- South Africa , Works councils -- South Africa
- Description: The promulgation into law of the concept of workplace forums has been beset with immense criticism and opposition from organized labour and some quarters of organized business. Last ditch efforts by the Ministerial Task Team had won the day for the inclusion of this controversial provision in the new Labour Relations Act.1 Commentators on the Act tend to agree that the fallout with organized labour at the negotiations has probably set the scene as to whether the provisions would be widely used or not. History has shown that the establishment of such forums in workplaces has been low. In some situations where workplace forums had been established, their continuous sustainability was put into doubt. This has led to the de-establishment of some of these forums in some workplaces. Various reasons were provided, but the prime factors for its failure could be traced back to the negotiations at NEDLAC. The unions opposed the original proposal by government that minority unions and even non-union employees can trigger the establishment of a workplace forum and insisted that this be restricted to majority unions. The voluntary nature regarding the establishment of a workplace forum and the trigger that only a majority union can invoke the provisions has still seen unions reluctant to utilize the provisions since it did not serve their purpose. The aims of the provisions, namely to increase workplace democracy, was therefore thwarted in favour of more informal procedures. Although the idea is a noble one, it is argued that the introduction of the provisions was ill-timed and inappropriate. The lesson that the legislature can take is that for any provision to be a success, buy-in from all stakeholders is paramount. Research has shown that there was a steady decline in the establishment of workplace forums. Since December 2004 there was not a single application received by the Commission for Conciliation, mediation and Arbitration. There is also doubt as to whether any of the Forums that were previously established are still functional. What is certain is that statutory workplace forums is not at the forefront as a vehicle for change that was envisaged in the Explanatory Memorandum that accompanied the new Labour Relations Act. What is also certain is that employers and employees are utilizing other forums to ensure workplace participation. These forums, however, only provide a voice to unionized workers. The vast majority of non-union workers remain voiceless. The proposed amendments in 2002 that intimated that the trigger be any union and not only majority unions failed to be passed into law. Perhaps it is that type of catalyst that is required to give life to the provisions. The future of workplace forums in South Africa is bleak and will continue to be if there is no intervention by the parties at NEDLAC to revive it. A complete revamp of the legislation would be required for such a revival. Some commentators have made meaningful suggestions on changes that can be made to the legislation to make workplace forums more attractive. Some have suggested it be scrapped altogether and future workplace participatory structures should be left to the parties to embrace voluntarily. Workplace forums are a novel innovation with great potential to encourage workplace democracy. There is nothing wrong with the concept. The application of such forums in the South African context is what is concerning. Perhaps prior experience and experimentation with similar type forums have tarnished workplace participation. The strategies by the previous regime and some employers have caused such participation to equate to co-option. Perhaps not enough spade work was done to ensure that the climate and attitude of the parties was conducive for its introduction. What is paramount no matter the form it takes is that workplace participation is crucial for economic growth and the introduction of new work methods to improve productivity. Without the establishment of such forums, whether voluntary or statutory, the ‘second channel principle’ that promotes non-adversarial workplace joint decision-making would be lost and conflict based participation could spiral leading to economic disaster.
- Full Text:
- Date Issued: 2007
Written medicines information for South African HIV/AIDS patients: does it enhance understanding of co-trimoxazole therapy?
- Mansoor, Leila E, Dowse, Roslind
- Authors: Mansoor, Leila E , Dowse, Roslind
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156860 , vital:40059 , https://0-doi.org.wam.seals.ac.za/10.1093/her/cyl039
- Description: Written information to promote patient education is being increasingly recognized as an integral part of quality health care. The main objective of this study was to evaluate the effect of distributing a patient information leaflet (PIL) on knowledge acquisition and recall. Two different PILs were designed for co-trimoxazole tablets: a simple, shorter PIL that incorporated pictograms and text and a text-only PIL that was longer and more complex. Human immunodeficiency virus-positive participants on chronic co-trimoxazole therapy were enrolled from five local primary health care clinics in Grahamstown, South Africa, and were randomly allocated to a Control Group (no PIL), Group A (text-only PIL) or Group B (simple PIL with pictograms).
- Full Text:
- Date Issued: 2007
- Authors: Mansoor, Leila E , Dowse, Roslind
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156860 , vital:40059 , https://0-doi.org.wam.seals.ac.za/10.1093/her/cyl039
- Description: Written information to promote patient education is being increasingly recognized as an integral part of quality health care. The main objective of this study was to evaluate the effect of distributing a patient information leaflet (PIL) on knowledge acquisition and recall. Two different PILs were designed for co-trimoxazole tablets: a simple, shorter PIL that incorporated pictograms and text and a text-only PIL that was longer and more complex. Human immunodeficiency virus-positive participants on chronic co-trimoxazole therapy were enrolled from five local primary health care clinics in Grahamstown, South Africa, and were randomly allocated to a Control Group (no PIL), Group A (text-only PIL) or Group B (simple PIL with pictograms).
- Full Text:
- Date Issued: 2007
Xylem as well as phloem sustains severe damage due to feeding by the Russian wheat aphid
- Saheed, S A, Liu, Lin, Jonsson, Lisbeth M V, Botha, Christiaan E J
- Authors: Saheed, S A , Liu, Lin , Jonsson, Lisbeth M V , Botha, Christiaan E J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6541 , http://hdl.handle.net/10962/d1005983
- Description: Investigation of comparative effects of feeding damage by the Russian wheat aphid (RWA, biotype SA1, Diuraphis noxia Mordvilko) on leaf blades of susceptible and resistant wheat cultivars (Triticum aestivum L. var Betta and Betta-Dn1 respectively) were carried out to establish the level of ultrastructural damage caused by this aphid and the possible limitation of damage induced which could be ascribed to the resistance gene Dn1 over the susceptible cultivar. Ultrastructurally, Betta-Dn1 sustained less damage to the vascular tissue as well as to the mesophyll during the experimental period. Both inter- and intracellular probes resulted in considerable saliva deposition as the aphids probed for suitable feeding sites. Salivary tracks were observed between and within mesophyll, bundle sheath cells as well as the vascular tissue, including the xylem. Disruption of organelles and cytoplasm resulted from cell probing and sheath deposition. Cell and organelle damage was more evident in the non-resistant Betta cultivar. The aphids probed for and fed from thin-walled sieve tubes preferentially. Few thick-walled sieve tubes showed evidence of either aphid probing or feeding-related damage. Saliva was deposited when the aphids probed inter- and intracellularly for feeding sites. The aphids appeared preferentially to probe for and feed from thin-walled sieve tubes, as few thick-walled sieve tubes showed evidence of damage. Vessels, apparently probed for water, contained watery saliva that encased the secondary walls and sealed pit membranes between probed vessels and xylem parenchyma. The xylem probed by the RWA was rendered non-functional, probably contributing to symptoms of leaf roll, chlorosis and necrosis, which were observed within two weeks of infestation in the susceptible Betta cultivar. This damage was limited in the resistant Betta-Dn1 cultivar during the same time frame.
- Full Text:
- Date Issued: 2007
- Authors: Saheed, S A , Liu, Lin , Jonsson, Lisbeth M V , Botha, Christiaan E J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6541 , http://hdl.handle.net/10962/d1005983
- Description: Investigation of comparative effects of feeding damage by the Russian wheat aphid (RWA, biotype SA1, Diuraphis noxia Mordvilko) on leaf blades of susceptible and resistant wheat cultivars (Triticum aestivum L. var Betta and Betta-Dn1 respectively) were carried out to establish the level of ultrastructural damage caused by this aphid and the possible limitation of damage induced which could be ascribed to the resistance gene Dn1 over the susceptible cultivar. Ultrastructurally, Betta-Dn1 sustained less damage to the vascular tissue as well as to the mesophyll during the experimental period. Both inter- and intracellular probes resulted in considerable saliva deposition as the aphids probed for suitable feeding sites. Salivary tracks were observed between and within mesophyll, bundle sheath cells as well as the vascular tissue, including the xylem. Disruption of organelles and cytoplasm resulted from cell probing and sheath deposition. Cell and organelle damage was more evident in the non-resistant Betta cultivar. The aphids probed for and fed from thin-walled sieve tubes preferentially. Few thick-walled sieve tubes showed evidence of either aphid probing or feeding-related damage. Saliva was deposited when the aphids probed inter- and intracellularly for feeding sites. The aphids appeared preferentially to probe for and feed from thin-walled sieve tubes, as few thick-walled sieve tubes showed evidence of damage. Vessels, apparently probed for water, contained watery saliva that encased the secondary walls and sealed pit membranes between probed vessels and xylem parenchyma. The xylem probed by the RWA was rendered non-functional, probably contributing to symptoms of leaf roll, chlorosis and necrosis, which were observed within two weeks of infestation in the susceptible Betta cultivar. This damage was limited in the resistant Betta-Dn1 cultivar during the same time frame.
- Full Text:
- Date Issued: 2007
Zebra fingerprints: towards a computer-aided identification system for individual zebra
- Foster, Gregory G, Krijer, Hans, Bangay, Shaun D
- Authors: Foster, Gregory G , Krijer, Hans , Bangay, Shaun D
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433482 , vital:72973 , https://doi.org/10.1145/1108590.1108616
- Description: The article presents a study which investigates the development of a computer-aided system for individual zebra identification based on the lateral side stripe pattern. The model proposed for individual animal identification is based on a combination of image processing and fingerprint identification technology. About 20 minutes of zebra footage was filmed at the Amakhala Game Reserve in South Africa. The study indicates that there is sufficient variation in lateral stripe patterns to differentiate individual animals.
- Full Text:
- Date Issued: 2007
- Authors: Foster, Gregory G , Krijer, Hans , Bangay, Shaun D
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433482 , vital:72973 , https://doi.org/10.1145/1108590.1108616
- Description: The article presents a study which investigates the development of a computer-aided system for individual zebra identification based on the lateral side stripe pattern. The model proposed for individual animal identification is based on a combination of image processing and fingerprint identification technology. About 20 minutes of zebra footage was filmed at the Amakhala Game Reserve in South Africa. The study indicates that there is sufficient variation in lateral stripe patterns to differentiate individual animals.
- Full Text:
- Date Issued: 2007