Agathis bishopi, a larval parasitoid of false codling moth Thaumatotibia leucotreta: laboratory rearing and effect of adult food on parasitism and longevity
- Zimba, Kennedy J, Moore, Sean D, Heshula, LU, Hill, Martin P
- Authors: Zimba, Kennedy J , Moore, Sean D , Heshula, LU , Hill, Martin P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406985 , vital:70328 , xlink:href="https://hdl.handle.net/10520/EJC185849"
- Description: Agathis bishopi (Nixon) (Hymenoptera: Braconidae) is a koinobiont larval endoparasitoid of false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), a pest of economic importance on citrus in South Africa. In the field Agathis bishopi was found to parasitise up to 34 % of FCM larvae in fruit, reflecting reasonable biocontrol potential. Improving the rearing of A. bishopi would therefore complement the existing biocontrol strategies for FCM. In several parasitic wasps, sugar concentration and feeding duration has been shown to influence parasitism and longevity. However, their effect on parasitism and longevity of A. bishopi is unknown. In the present study a rearing protocol for A. bishopi is described, including evaluation of the effects of honey concentration on parasitoid longevity. On average, 18.2%of FCM larvae in rearing containers were parasitised under the rearing protocol described. Cotton wool, instead of paper towelling, as honey carrier for feeding parasitoids in rearing containers significantly increased parasitism and yield of offspring. Furthermore, longevity significantly increased with higher concentrations of honey. Maximum lifespan duration for male and female parasitoids was achieved when parasitoids were fed on 36 % (w/v) honey. Results from this study indicate that A. bishopi requires a sufficient concentration of sugar, coupled with frequent and prolonged feeding on a cotton wool substrate, in order to achieve maximum parasitism and longevity. Such information provides a basis for optimising mass-rearing and longevity of A. bishopi and parasitism of FCM in orchards.
- Full Text:
- Authors: Zimba, Kennedy J , Moore, Sean D , Heshula, LU , Hill, Martin P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406985 , vital:70328 , xlink:href="https://hdl.handle.net/10520/EJC185849"
- Description: Agathis bishopi (Nixon) (Hymenoptera: Braconidae) is a koinobiont larval endoparasitoid of false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), a pest of economic importance on citrus in South Africa. In the field Agathis bishopi was found to parasitise up to 34 % of FCM larvae in fruit, reflecting reasonable biocontrol potential. Improving the rearing of A. bishopi would therefore complement the existing biocontrol strategies for FCM. In several parasitic wasps, sugar concentration and feeding duration has been shown to influence parasitism and longevity. However, their effect on parasitism and longevity of A. bishopi is unknown. In the present study a rearing protocol for A. bishopi is described, including evaluation of the effects of honey concentration on parasitoid longevity. On average, 18.2%of FCM larvae in rearing containers were parasitised under the rearing protocol described. Cotton wool, instead of paper towelling, as honey carrier for feeding parasitoids in rearing containers significantly increased parasitism and yield of offspring. Furthermore, longevity significantly increased with higher concentrations of honey. Maximum lifespan duration for male and female parasitoids was achieved when parasitoids were fed on 36 % (w/v) honey. Results from this study indicate that A. bishopi requires a sufficient concentration of sugar, coupled with frequent and prolonged feeding on a cotton wool substrate, in order to achieve maximum parasitism and longevity. Such information provides a basis for optimising mass-rearing and longevity of A. bishopi and parasitism of FCM in orchards.
- Full Text:
Host searching and oviposition behaviour of Agathis bishopi (Hymenoptera: Braconidae), a larval parasitoid of false codling moth, Thaumatotibia leucotreta (Lepidoptera: Tortricidae): a potential proxy indicator for fruit infestation
- Zimba, Kennedy J, Heshula, LU, Moore, Sean D, Hill, Martin P
- Authors: Zimba, Kennedy J , Heshula, LU , Moore, Sean D , Hill, Martin P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/407019 , vital:70330 , xlink:href="https://hdl.handle.net/10520/EJC195073"
- Description: Agathis bishopi (Nixon) (Hymenoptera: Braconidae)is an arrhenotokous larval endoparasitoid of Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) (Gendall 2007; Hofmeyr et al. 2015) commonly known as false codling moth (FCM), a major pest of citrus in South Africa (Moore et al. 2004; Malan et al. 2011). Under field conditions, A. bishopi was identified attacking more than 34% of FCM larvae in fruit, showing good biocontrol potential (Gendall 2007). Preference by A. bishopi for parasitising the early instars of its concealed host suggests that the parasitoid has strong natural host location ability (Sishuba 2003; Gendall 2007).
- Full Text:
- Authors: Zimba, Kennedy J , Heshula, LU , Moore, Sean D , Hill, Martin P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/407019 , vital:70330 , xlink:href="https://hdl.handle.net/10520/EJC195073"
- Description: Agathis bishopi (Nixon) (Hymenoptera: Braconidae)is an arrhenotokous larval endoparasitoid of Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) (Gendall 2007; Hofmeyr et al. 2015) commonly known as false codling moth (FCM), a major pest of citrus in South Africa (Moore et al. 2004; Malan et al. 2011). Under field conditions, A. bishopi was identified attacking more than 34% of FCM larvae in fruit, showing good biocontrol potential (Gendall 2007). Preference by A. bishopi for parasitising the early instars of its concealed host suggests that the parasitoid has strong natural host location ability (Sishuba 2003; Gendall 2007).
- Full Text:
Agathis bishopi (Hymenoptera: Braconidae) as a potential tool for detecting oranges infested with Thaumatotibia leucotreta (Lepidoptera: Tortricidae)
- Zimba, Kennedy J, Hill, Martin P, Moore, Sean D, Heshula, Unathi
- Authors: Zimba, Kennedy J , Hill, Martin P , Moore, Sean D , Heshula, Unathi
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423955 , vital:72108 , xlink:href="https://doi.org/10.1007/s10905-015-9526-0"
- Description: In South Africa, Thaumatotibia leucotreta is a key pest of citrus impacting its production and trade. Detection of newly infested fruit by visual inspection is challenging and poses a risk of packing infested with healthy fruit for export. Agathis bishopi is a larval endoparasitoid of T. leucotreta, attacking early larval instars. Understanding how A. bishopi parasitoids locate fruit infested with their host is of interest for developing an efficient detector for T. leucotreta infested fruit. The response of female adult A. bishopi parasitoids to olfactory and visual cues associated with T. leucotreta infested fruit were evaluated using a Y-tube olfactometer and flight tunnel. Agathis bishopi parasitoids were strongly attracted to infested fruit over healthy fruit, either when only olfactory or combinations of visual and olfactory cues were offered. Among the four synthetic compounds tested, D-limonene and ocimene elicited a strong attraction to parasitoids with response rates of 92 % and 72 % respectively. A blend of four synthetic compounds simulating T. leucotreta infested fruit odour equally elicited strong attraction to parasitoids (84 % response rate). Attraction of parasitoids to infested fruit cues was heightened by prior experience, suggesting the occurrence of associative learning. Results from this study indicate that A. bishopi parasitoids mainly rely on olfactory cues in host habitat location and that D-limonene and ocimene are the major attractants in infested fruit volatiles. These findings and the potential for manipulating A. bishopi for detection of infested fruit in the packhouse are discussed.
- Full Text:
- Authors: Zimba, Kennedy J , Hill, Martin P , Moore, Sean D , Heshula, Unathi
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423955 , vital:72108 , xlink:href="https://doi.org/10.1007/s10905-015-9526-0"
- Description: In South Africa, Thaumatotibia leucotreta is a key pest of citrus impacting its production and trade. Detection of newly infested fruit by visual inspection is challenging and poses a risk of packing infested with healthy fruit for export. Agathis bishopi is a larval endoparasitoid of T. leucotreta, attacking early larval instars. Understanding how A. bishopi parasitoids locate fruit infested with their host is of interest for developing an efficient detector for T. leucotreta infested fruit. The response of female adult A. bishopi parasitoids to olfactory and visual cues associated with T. leucotreta infested fruit were evaluated using a Y-tube olfactometer and flight tunnel. Agathis bishopi parasitoids were strongly attracted to infested fruit over healthy fruit, either when only olfactory or combinations of visual and olfactory cues were offered. Among the four synthetic compounds tested, D-limonene and ocimene elicited a strong attraction to parasitoids with response rates of 92 % and 72 % respectively. A blend of four synthetic compounds simulating T. leucotreta infested fruit odour equally elicited strong attraction to parasitoids (84 % response rate). Attraction of parasitoids to infested fruit cues was heightened by prior experience, suggesting the occurrence of associative learning. Results from this study indicate that A. bishopi parasitoids mainly rely on olfactory cues in host habitat location and that D-limonene and ocimene are the major attractants in infested fruit volatiles. These findings and the potential for manipulating A. bishopi for detection of infested fruit in the packhouse are discussed.
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Meso-and axially-modified IrIIItriarylcorroles with tunable electrocatalytic properties
- Zhang, Xifeng, Wang, Yu, Zhu, Weihua, Mack, John, Soy, Rodah C, Nyokong, Tebello, Liang, Xu
- Authors: Zhang, Xifeng , Wang, Yu , Zhu, Weihua , Mack, John , Soy, Rodah C , Nyokong, Tebello , Liang, Xu
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190851 , vital:45034 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.02.040"
- Description: The synthesis of three A2B type Ir(III)triarylcorroles with meso-aryl substituents that provide electron donating (push) and withdrawing (pull) properties and three A3 type IrIIItriphenylcorroles with differing pyridine axial ligands is reported, along with their structural characterization. An analysis of the structure-property relationships in the optical and redox properties has been carried out by comparing their optical spectroscopy and electrochemistry to trends predicted in DFT and TD-DFT calculations. The results demonstrate that A2B type IrIIItriarylcorroles are highly efficient electrocatalyzed oxygen reduction reactions (ORRs) and that their reactivity can be modulated by modulating the electronic structure by changing the nature of the meso-substituent at the B-positions, and even axial pyridine ligands.
- Full Text:
- Authors: Zhang, Xifeng , Wang, Yu , Zhu, Weihua , Mack, John , Soy, Rodah C , Nyokong, Tebello , Liang, Xu
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190851 , vital:45034 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.02.040"
- Description: The synthesis of three A2B type Ir(III)triarylcorroles with meso-aryl substituents that provide electron donating (push) and withdrawing (pull) properties and three A3 type IrIIItriphenylcorroles with differing pyridine axial ligands is reported, along with their structural characterization. An analysis of the structure-property relationships in the optical and redox properties has been carried out by comparing their optical spectroscopy and electrochemistry to trends predicted in DFT and TD-DFT calculations. The results demonstrate that A2B type IrIIItriarylcorroles are highly efficient electrocatalyzed oxygen reduction reactions (ORRs) and that their reactivity can be modulated by modulating the electronic structure by changing the nature of the meso-substituent at the B-positions, and even axial pyridine ligands.
- Full Text:
Exploring patterns of Facebook usage, social capital, loneliness and well-being among a diverse South African student sample:
- Young, Charles, Strelitz, Larry N
- Authors: Young, Charles , Strelitz, Larry N
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143705 , vital:38275 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: There has been much debate over whether the use of social network sites isolate people and truncate their relationships or alternatively, provide beneficial connections with others. This debate has been framed by a growing international literature which explores the triadic relationship between the intensity of use of Facebook to the maintenance of social capital and in turn the relationship between social capital and wellbeing and loneliness. A random list of 1168 Rhodes University students was drawn from the total student body and invited to participate in an online survey. In total, 491 students completed the survey (42% response rate). Hierarchical regression analyses demonstrate that intensity of Facebook usage adds a very small contribution to social capital, is very weakly associated with loneliness, and is not associated with wellbeing. Results contrast with international studies that fail to recognise the extent to which race and class cleavages impact on access to and use of social media.
- Full Text:
- Authors: Young, Charles , Strelitz, Larry N
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143705 , vital:38275 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: There has been much debate over whether the use of social network sites isolate people and truncate their relationships or alternatively, provide beneficial connections with others. This debate has been framed by a growing international literature which explores the triadic relationship between the intensity of use of Facebook to the maintenance of social capital and in turn the relationship between social capital and wellbeing and loneliness. A random list of 1168 Rhodes University students was drawn from the total student body and invited to participate in an online survey. In total, 491 students completed the survey (42% response rate). Hierarchical regression analyses demonstrate that intensity of Facebook usage adds a very small contribution to social capital, is very weakly associated with loneliness, and is not associated with wellbeing. Results contrast with international studies that fail to recognise the extent to which race and class cleavages impact on access to and use of social media.
- Full Text:
A sandbox-based approach to the deobfuscation and dissection of php-based malware
- Wrench, Peter M, Irwin, Barry V W
- Authors: Wrench, Peter M , Irwin, Barry V W
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429258 , vital:72571 , 10.23919/SAIEE.2015.8531886
- Description: The creation and proliferation of PHP-based Remote Access Trojans (or web shells) used in both the compromise and post exploitation of web platforms has fuelled research into automated methods of dissecting and analysing these shells. Current malware tools disguise themselves by making use of obfuscation techniques designed to frustrate any efforts to dissect or reverse engineer the code. Advanced code engineering can even cause malware to behave differently if it detects that it is not running on the system for which it was originally targeted. To combat these defensive techniques, this paper presents a sandbox-based environment that aims to accurately mimic a vulnerable host and is capable of semi-automatic semantic dissection and syntactic deobfuscation of PHP code.
- Full Text:
- Authors: Wrench, Peter M , Irwin, Barry V W
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429258 , vital:72571 , 10.23919/SAIEE.2015.8531886
- Description: The creation and proliferation of PHP-based Remote Access Trojans (or web shells) used in both the compromise and post exploitation of web platforms has fuelled research into automated methods of dissecting and analysing these shells. Current malware tools disguise themselves by making use of obfuscation techniques designed to frustrate any efforts to dissect or reverse engineer the code. Advanced code engineering can even cause malware to behave differently if it detects that it is not running on the system for which it was originally targeted. To combat these defensive techniques, this paper presents a sandbox-based environment that aims to accurately mimic a vulnerable host and is capable of semi-automatic semantic dissection and syntactic deobfuscation of PHP code.
- Full Text:
Condoms in pockets and HIV-free certificates: mother-daughter communication about sex and risk in a time of AIDS epidemic in South Africa
- Authors: Wilbraham, Lindy
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143693 , vital:38274 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Responsive to the perceived high risks of sexual coercion, unwanted pregnancy and HIV-infection of girls in particular, several South African sexual health promotion campaigns have used media targeting parents (mothers in particular) to instruct them on how sex should be talked about with young people to ‘risk-proof’ them. Such an instrumentalist public health discourse posits this intergenerational communication as an ‘ongoing discussion’ of events, feelings, issues and risk-safe practices around heterosexual sex negotiation. A Foucauldian view finds these conversational imperatives pitched against much-talked-about resistances to talking about sex; and the saturation with risk of ambivalent mothers and silent daughters. Mother-daughter communication about sex and sexualities – as an uneasy western ideal of attachment parenting – has tangled roots in psychoanalytic theory and feminisms where sex as the core of modern subjectivity is normalized, capacities for intimacy are trained, and affiliative sexuality is modelled in ways that balance the rights and responsibilities of sexual agency/citizenship. This paper begins with two narrative fragments from a sexual health campaign that addressed mothers and daughters, and recounts how these ‘stories’ produced derisive laughter when introduced into group discussions with young/older women. The paper follows two lines of exploration. Firstly, is western idealized fabrication of inter-subjectivity between mothers and daughters desirable and feasible in post-apartheid conditions of epidemic in South Africa? And secondly, what if the narratives of lives and experiences we offer by way of health education materials provoke uncertainties, gaps and interrogations about sex, mothering and communication, instead of offering homilies and solutions?
- Full Text:
- Authors: Wilbraham, Lindy
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143693 , vital:38274 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Responsive to the perceived high risks of sexual coercion, unwanted pregnancy and HIV-infection of girls in particular, several South African sexual health promotion campaigns have used media targeting parents (mothers in particular) to instruct them on how sex should be talked about with young people to ‘risk-proof’ them. Such an instrumentalist public health discourse posits this intergenerational communication as an ‘ongoing discussion’ of events, feelings, issues and risk-safe practices around heterosexual sex negotiation. A Foucauldian view finds these conversational imperatives pitched against much-talked-about resistances to talking about sex; and the saturation with risk of ambivalent mothers and silent daughters. Mother-daughter communication about sex and sexualities – as an uneasy western ideal of attachment parenting – has tangled roots in psychoanalytic theory and feminisms where sex as the core of modern subjectivity is normalized, capacities for intimacy are trained, and affiliative sexuality is modelled in ways that balance the rights and responsibilities of sexual agency/citizenship. This paper begins with two narrative fragments from a sexual health campaign that addressed mothers and daughters, and recounts how these ‘stories’ produced derisive laughter when introduced into group discussions with young/older women. The paper follows two lines of exploration. Firstly, is western idealized fabrication of inter-subjectivity between mothers and daughters desirable and feasible in post-apartheid conditions of epidemic in South Africa? And secondly, what if the narratives of lives and experiences we offer by way of health education materials provoke uncertainties, gaps and interrogations about sex, mothering and communication, instead of offering homilies and solutions?
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Brown hyena habitat selection varies among sites in a semi-arid region of southern Africa
- Welch, Rebecca J, Tambling, Craig J, Bissett, Charlene, Gaylard, Angela, Müller, Konrad, Slater, Kerry, Strauss, W Maartin, Parker, Daniel M
- Authors: Welch, Rebecca J , Tambling, Craig J , Bissett, Charlene , Gaylard, Angela , Müller, Konrad , Slater, Kerry , Strauss, W Maartin , Parker, Daniel M
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123277 , vital:35423 , https://doi.10.1093/jmammal/gyv189
- Description: In the last 50 years, the human impact on ecosystems has been greater than during any other time period in human history (Millennium Ecosystem Assessment 2003). Large carnivores face anthropogenic threats worldwide, specifically persecution, habitat degradation, and habitat fragmentation (Everatt et al. 2014; Groom et al. 2014; Ripple et al. 2014; Wolfe et al. 2015). Because large carnivores often occupy high trophic levels, their presence influences species at lower levels through trophic cascades (Ripple et al. 2014). Natural experiments, taking advantage of large carnivore management, have shown that large predators provide fundamental ecosystem and economic services that help maintain healthy and diverse ecosystems (Ripple et al. 2014). Additionally, carnivores play an important role in other ecosystem processes, for example, scavenging carnivores may provide regulatory services, such as waste removal, nutrient cycling, and disease regulation. Such services add stability to ecosystems and ensure energy flow through multiple trophic levels (DeVault et al. 2003; Wilson and Wolkovich 2011).
- Full Text:
- Authors: Welch, Rebecca J , Tambling, Craig J , Bissett, Charlene , Gaylard, Angela , Müller, Konrad , Slater, Kerry , Strauss, W Maartin , Parker, Daniel M
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123277 , vital:35423 , https://doi.10.1093/jmammal/gyv189
- Description: In the last 50 years, the human impact on ecosystems has been greater than during any other time period in human history (Millennium Ecosystem Assessment 2003). Large carnivores face anthropogenic threats worldwide, specifically persecution, habitat degradation, and habitat fragmentation (Everatt et al. 2014; Groom et al. 2014; Ripple et al. 2014; Wolfe et al. 2015). Because large carnivores often occupy high trophic levels, their presence influences species at lower levels through trophic cascades (Ripple et al. 2014). Natural experiments, taking advantage of large carnivore management, have shown that large predators provide fundamental ecosystem and economic services that help maintain healthy and diverse ecosystems (Ripple et al. 2014). Additionally, carnivores play an important role in other ecosystem processes, for example, scavenging carnivores may provide regulatory services, such as waste removal, nutrient cycling, and disease regulation. Such services add stability to ecosystems and ensure energy flow through multiple trophic levels (DeVault et al. 2003; Wilson and Wolkovich 2011).
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Characterisation of the HSP70-HSP90 organising protein gene and its link to cancer
- Authors: Weeks, Stacey
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/56006 , vital:26764
- Description: HOP (Heat shock protein 70/ Heat shock protein 90 organising protein) is a co-chaperone essential for client protein transfer from HSP70 to HSP90 within the HSP90 chaperone machine and has been found to be up-regulated in various cancers. However, minimal in vitro information can be found on the regulation of HOP expression. The aim of this study was to analyse the HOP gene structure across known orthologues, identify and characterise the HOP promoter, and identify the regulatory mechanisms influencing the expression of HOP in cancer. We hypothesized that the expression of HOP in cancer cells is likely regulated by oncogenic signalling pathways linked to cis-elements within the HOP promoter. An initial study of the evolution of the HOP gene speciation was performed across identified orthologues using Mega5.2. The evolutionary pathway of the HOP gene was traced from the unicellular organisms to fish, to amphibian and then to land mammal. The synteny across the orthologues was identified and the co-expression profile of HOP analysed. We identified the putative promoter region for HOP in silico and in vitro. Luciferase reporter assays were utilized to demonstrate promoter activity of the upstream region in vitro. Bioinformatic analysis of the active promoter region identified a large CpG island and a range of putative cis-elements. Many of the cis-elements interact with transcription factors which are activated by oncogenic pathways. We therefore tested the regulation of HOP levels by rat sarcoma viral oncogene homologue (RAS). Cancer cell lines were transfected with mutated RAS to observe the effect of constitutively active RAS expression on the production of HOP using qRT-PCR and Western Blot analyses. Additionally, inhibitors of the RAS signalling pathway were utilised to confirm the regulatory effect of mutated RAS on HOP expression. In cancer cell lines containing mutated RAS (Hs578T), HOP was up-regulated via a mechanism involving the MAPK signalling pathway and the ETS-1 and C/EBPβ cis-elements within the HOP promoter. These findings suggest for the first time that Hop expression in cancer may be regulated by RAS activation of the HOP promoter. Additionally, this study allowed us to determine the murine system to be the most suited genetic model organism with which to study the function of human HOP.
- Full Text:
- Authors: Weeks, Stacey
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/56006 , vital:26764
- Description: HOP (Heat shock protein 70/ Heat shock protein 90 organising protein) is a co-chaperone essential for client protein transfer from HSP70 to HSP90 within the HSP90 chaperone machine and has been found to be up-regulated in various cancers. However, minimal in vitro information can be found on the regulation of HOP expression. The aim of this study was to analyse the HOP gene structure across known orthologues, identify and characterise the HOP promoter, and identify the regulatory mechanisms influencing the expression of HOP in cancer. We hypothesized that the expression of HOP in cancer cells is likely regulated by oncogenic signalling pathways linked to cis-elements within the HOP promoter. An initial study of the evolution of the HOP gene speciation was performed across identified orthologues using Mega5.2. The evolutionary pathway of the HOP gene was traced from the unicellular organisms to fish, to amphibian and then to land mammal. The synteny across the orthologues was identified and the co-expression profile of HOP analysed. We identified the putative promoter region for HOP in silico and in vitro. Luciferase reporter assays were utilized to demonstrate promoter activity of the upstream region in vitro. Bioinformatic analysis of the active promoter region identified a large CpG island and a range of putative cis-elements. Many of the cis-elements interact with transcription factors which are activated by oncogenic pathways. We therefore tested the regulation of HOP levels by rat sarcoma viral oncogene homologue (RAS). Cancer cell lines were transfected with mutated RAS to observe the effect of constitutively active RAS expression on the production of HOP using qRT-PCR and Western Blot analyses. Additionally, inhibitors of the RAS signalling pathway were utilised to confirm the regulatory effect of mutated RAS on HOP expression. In cancer cell lines containing mutated RAS (Hs578T), HOP was up-regulated via a mechanism involving the MAPK signalling pathway and the ETS-1 and C/EBPβ cis-elements within the HOP promoter. These findings suggest for the first time that Hop expression in cancer may be regulated by RAS activation of the HOP promoter. Additionally, this study allowed us to determine the murine system to be the most suited genetic model organism with which to study the function of human HOP.
- Full Text:
Seasonal consumption of browse by the African buffalo (Syncerus caffer) in the Thicket Biome of South Africa
- Watermeyer, Jessica P, Carroll, Sarah L, Parker, Daniel M
- Authors: Watermeyer, Jessica P , Carroll, Sarah L , Parker, Daniel M
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126096 , vital:35849 , https://doi.org/10.1111/aje.12214
- Description: The African buffalo (Syncerus caffer Sparrman) is both morphologically and physiologically adapted for grazing (Prins, 1996). However, buffalo populations of the Eastern Cape, South Africa, are confined to reserves dominated by thicket vegetation where grass is sparse (Landman & Kerley, 2001; Tshabalala, Dube & Lent, 2009). Given that the nutritional value of grass deteriorates more rapidly than browse in nonproductive periods (Shipley, 1993), it has been hypothesized that buffalo increase their intake of browse during the dry season (Tshabalala, Dube & Lent, 2009). However, past studies contradict one another (de Graaf, Schulz & van der Walt, 1973; Landman & Kerley, 2001; Tshabalala, Dube & Lent, 2009). de Graaf, Schulz & van der Walt (1973) analysed the rumen contents of buffalo in the Addo Elephant National Park and suggested that buffalo should be considered browsers because of the high proportion of browse in rumen samples. However, their study was restricted to one site during a drought. Landman & Kerley (2001) later found the opposite (grass comprised ~72% of buffalo dung) and criticized the findings of de Graaf, Schulz amp; van der Walt (1973). However, their study was conducted after a period of exceptionally high rainfall. More recently, Tshabalala, Dube & Lent (2009) recorded significantly more browse in the diet of buffalo during the dry season (33%) than the wet season (28%) at the Great Fish River Nature Reserve. We test the assertion that buffalo increase their intake of browse during dry periods, at another site dominated by thicket. We describe the extent to which grass and browse were consumed by buffalo and whether the proportional occurrence changed monthly.
- Full Text:
- Authors: Watermeyer, Jessica P , Carroll, Sarah L , Parker, Daniel M
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126096 , vital:35849 , https://doi.org/10.1111/aje.12214
- Description: The African buffalo (Syncerus caffer Sparrman) is both morphologically and physiologically adapted for grazing (Prins, 1996). However, buffalo populations of the Eastern Cape, South Africa, are confined to reserves dominated by thicket vegetation where grass is sparse (Landman & Kerley, 2001; Tshabalala, Dube & Lent, 2009). Given that the nutritional value of grass deteriorates more rapidly than browse in nonproductive periods (Shipley, 1993), it has been hypothesized that buffalo increase their intake of browse during the dry season (Tshabalala, Dube & Lent, 2009). However, past studies contradict one another (de Graaf, Schulz & van der Walt, 1973; Landman & Kerley, 2001; Tshabalala, Dube & Lent, 2009). de Graaf, Schulz & van der Walt (1973) analysed the rumen contents of buffalo in the Addo Elephant National Park and suggested that buffalo should be considered browsers because of the high proportion of browse in rumen samples. However, their study was restricted to one site during a drought. Landman & Kerley (2001) later found the opposite (grass comprised ~72% of buffalo dung) and criticized the findings of de Graaf, Schulz amp; van der Walt (1973). However, their study was conducted after a period of exceptionally high rainfall. More recently, Tshabalala, Dube & Lent (2009) recorded significantly more browse in the diet of buffalo during the dry season (33%) than the wet season (28%) at the Great Fish River Nature Reserve. We test the assertion that buffalo increase their intake of browse during dry periods, at another site dominated by thicket. We describe the extent to which grass and browse were consumed by buffalo and whether the proportional occurrence changed monthly.
- Full Text:
Preliminary evidence for the organisation of a bacterial community by zooplanktivores at the top of an estuarine planktonic food web
- Wasserman, Ryan J, Matcher, Gwynneth F, Vink, Tim J F, Froneman, P William
- Authors: Wasserman, Ryan J , Matcher, Gwynneth F , Vink, Tim J F , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68237 , vital:29222 , https://doi.org/10.1007/s00248-014-0505-3
- Description: Publisher version , As part of a larger investigation, the effect of apex predation on estuarine bacterial community structure, through trophic cascading, was investigated using experimental in situ mesocosms. Through either the removal (filtration) or addition of specific size classes of planktonic groups, four different trophic scenarios were established using estuarine water and its associated plankton. One such treatment represented a “natural” scenario in which stable apex predatory pressure was qualified. Water samples were collected over time from each of the treatments for bacterial community evaluation. These samples were assessed through pyrosequencing of the variable regions 4 and 5 of the bacterial 16S rRNA gene and analysed at the species operational taxonomic unit (OTU) level using a community procedure. The blue-green group dominated the samples, followed by Proteobacteria and Bacteroidetes. Samples were the most similar among treatments at the commencement of the experiment. While the bacterial communities sampled within each treatment changed over time, the deviation from initial appeared to be linked to the treatment trophic scenarios. The least temporal deviation-from-initial in bacterial community was found within the stable apex predatory pressure treatment. These findings are consistent with trophic cascade theory, whereby predators mediate interactions at multiple lower trophic levels with consequent repercussions for diversity.
- Full Text: false
- Authors: Wasserman, Ryan J , Matcher, Gwynneth F , Vink, Tim J F , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68237 , vital:29222 , https://doi.org/10.1007/s00248-014-0505-3
- Description: Publisher version , As part of a larger investigation, the effect of apex predation on estuarine bacterial community structure, through trophic cascading, was investigated using experimental in situ mesocosms. Through either the removal (filtration) or addition of specific size classes of planktonic groups, four different trophic scenarios were established using estuarine water and its associated plankton. One such treatment represented a “natural” scenario in which stable apex predatory pressure was qualified. Water samples were collected over time from each of the treatments for bacterial community evaluation. These samples were assessed through pyrosequencing of the variable regions 4 and 5 of the bacterial 16S rRNA gene and analysed at the species operational taxonomic unit (OTU) level using a community procedure. The blue-green group dominated the samples, followed by Proteobacteria and Bacteroidetes. Samples were the most similar among treatments at the commencement of the experiment. While the bacterial communities sampled within each treatment changed over time, the deviation from initial appeared to be linked to the treatment trophic scenarios. The least temporal deviation-from-initial in bacterial community was found within the stable apex predatory pressure treatment. These findings are consistent with trophic cascade theory, whereby predators mediate interactions at multiple lower trophic levels with consequent repercussions for diversity.
- Full Text: false
Spawning and nest guarding of the river goby (Glossogobius callidus) from the Eastern Cape province of South Africa
- Wasserman, Ryan J, Vink, Tim J F, Woodford, Darragh J, Froneman, P William
- Authors: Wasserman, Ryan J , Vink, Tim J F , Woodford, Darragh J , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68144 , vital:29203 , https://doi.org/10.1111/aje.12228
- Description: Publisher version , Introduction: The River goby, Glossogobius callidus (Smith 1937), occurs naturally in rivers and the upper reaches of estuaries along the eastern seaboard of southern Africa (Whitfield, 1998; James et al., 2007; Wasserman, Strydom & Wooldridge, 2010). This fish species is among the most abundant of fishes in many river systems of the region and is considered an important predator in these habitats, feeding on invertebrates and small fish (Whitfield, 1998; Strydom & Neira, 2006; Wasserman, 2012; Wasserman et al., 2014). Despite this, ecological information on this goby is sparse and to date, no published records on the biology of the species exist. The urgent need for such information was recently highlighted in a study that identified G. callidus as a potentially invasive species, given its ability to rapidly establish in novel environments (Woodford et al., 2013). The present study therefore endeavoured to determine the reproductive guild to which G. callidus belong and describe aspects of their spawning. This was performed by closely observing wild caught, mature G. callidus in aquaria over a 25-day period.
- Full Text: false
- Authors: Wasserman, Ryan J , Vink, Tim J F , Woodford, Darragh J , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68144 , vital:29203 , https://doi.org/10.1111/aje.12228
- Description: Publisher version , Introduction: The River goby, Glossogobius callidus (Smith 1937), occurs naturally in rivers and the upper reaches of estuaries along the eastern seaboard of southern Africa (Whitfield, 1998; James et al., 2007; Wasserman, Strydom & Wooldridge, 2010). This fish species is among the most abundant of fishes in many river systems of the region and is considered an important predator in these habitats, feeding on invertebrates and small fish (Whitfield, 1998; Strydom & Neira, 2006; Wasserman, 2012; Wasserman et al., 2014). Despite this, ecological information on this goby is sparse and to date, no published records on the biology of the species exist. The urgent need for such information was recently highlighted in a study that identified G. callidus as a potentially invasive species, given its ability to rapidly establish in novel environments (Woodford et al., 2013). The present study therefore endeavoured to determine the reproductive guild to which G. callidus belong and describe aspects of their spawning. This was performed by closely observing wild caught, mature G. callidus in aquaria over a 25-day period.
- Full Text: false
Fish predation regimes modify benthic diatom community structures: experimental evidence from an in situ mesocosm study
- Wasserman, Ryan J, Vink, Tim J F, Dalu, Tatenda, Froneman, P William
- Authors: Wasserman, Ryan J , Vink, Tim J F , Dalu, Tatenda , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68052 , vital:29190 , https://doi.org/10.1111/aec.12255
- Description: Publisher version , Diatoms are important primary producers in shallow water environments. Few studies have assessed the importance of biological interactions in structuring these communities. In the present study, benthic diatom community structure in relation to manipulated food webs was assessed using in situ mesocosms, whereby predator-free environments and environments comprising two different fish species were assessed. Zooplankton abundance, settled algal biomass and the diatom community were monitored over a 12‐day period across each of the three trophic scenarios. Differences among treatments over time were observed in zooplankton abundances, particularly copepods. Similarly, the benthic diatom community structure changed significantly over time across the three trophic treatments. However, no differences in total algal biomass were found among treatments. This was likely the result of non‐diatom phytoplankton contributions. We propose that the benthic diatom community structure within the mesocosms was influenced by trophic cascades and potentially through direct consumption by the fish. The study highlights that not only are organisms at the base of the food web affected by predators at the top of the food web, but that predator identity is potentially an important consideration for predator–prey interaction outcomes with consequences for multiple trophic levels.
- Full Text: false
- Authors: Wasserman, Ryan J , Vink, Tim J F , Dalu, Tatenda , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68052 , vital:29190 , https://doi.org/10.1111/aec.12255
- Description: Publisher version , Diatoms are important primary producers in shallow water environments. Few studies have assessed the importance of biological interactions in structuring these communities. In the present study, benthic diatom community structure in relation to manipulated food webs was assessed using in situ mesocosms, whereby predator-free environments and environments comprising two different fish species were assessed. Zooplankton abundance, settled algal biomass and the diatom community were monitored over a 12‐day period across each of the three trophic scenarios. Differences among treatments over time were observed in zooplankton abundances, particularly copepods. Similarly, the benthic diatom community structure changed significantly over time across the three trophic treatments. However, no differences in total algal biomass were found among treatments. This was likely the result of non‐diatom phytoplankton contributions. We propose that the benthic diatom community structure within the mesocosms was influenced by trophic cascades and potentially through direct consumption by the fish. The study highlights that not only are organisms at the base of the food web affected by predators at the top of the food web, but that predator identity is potentially an important consideration for predator–prey interaction outcomes with consequences for multiple trophic levels.
- Full Text: false
Towards shaping the field: theorising the knowledge in a formal course for academic developers
- Vorster, Jo-Anne, Quinn, Lynn
- Authors: Vorster, Jo-Anne , Quinn, Lynn
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66578 , vital:28966 , https://doi.org/10.1080/07294360.2015.1070126
- Description: publisher version , In recent years there have been calls both for building the knowledge base of academic development (AD) and for systematic induction of newcomers to the field if AD is to advance as a professional and an academic field. Despite the importance and complexity of AD, induction of novice academic developers remains mostly informal and predominantly focuses on the practices of the field. We argue that more-experienced academic developers have an obligation to provide formal and systematic routes into the field and its knowledge base than is currently the case. One way of doing this is through offering a formal course for growing the next generation of academic developers. Such a course could equip newcomers with a more solid and shared knowledge base, thus contributing to shaping the epistemic spine of AD. In this paper, using Maton's Legitimation Code Theory, we offer an analysis of an existing course aimed at equipping novices with the theoretical and practical knowledge to enable them to solve some of the problems in higher education. From this analysis have emerged general principles that could inform the selection, sequencing and pacing of knowledge in a formal course for academic developers.
- Full Text: false
- Authors: Vorster, Jo-Anne , Quinn, Lynn
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66578 , vital:28966 , https://doi.org/10.1080/07294360.2015.1070126
- Description: publisher version , In recent years there have been calls both for building the knowledge base of academic development (AD) and for systematic induction of newcomers to the field if AD is to advance as a professional and an academic field. Despite the importance and complexity of AD, induction of novice academic developers remains mostly informal and predominantly focuses on the practices of the field. We argue that more-experienced academic developers have an obligation to provide formal and systematic routes into the field and its knowledge base than is currently the case. One way of doing this is through offering a formal course for growing the next generation of academic developers. Such a course could equip newcomers with a more solid and shared knowledge base, thus contributing to shaping the epistemic spine of AD. In this paper, using Maton's Legitimation Code Theory, we offer an analysis of an existing course aimed at equipping novices with the theoretical and practical knowledge to enable them to solve some of the problems in higher education. From this analysis have emerged general principles that could inform the selection, sequencing and pacing of knowledge in a formal course for academic developers.
- Full Text: false
'Tell us a new story': a proposal for the transformatory potential of collective memory projects
- Authors: Vincent, Louise
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/${Handle} , vital:38046 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
- Authors: Vincent, Louise
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/${Handle} , vital:38046 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
Restricted physical activity research in older women: does this represent additional risk to health?
- Viljoen, Janet E, Christie, Candice J
- Authors: Viljoen, Janet E , Christie, Candice J
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143682 , vital:38273 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Post-menopausal women are at great risk of developing cardiovascular disease due to the loss of endogenous estrogen at menopause. This risk can be mediated via medication, but this route is costly and carries the risk of side effects which can reduce quality of life experience. The benefit of a lifestyle management approach to such risk, particularly via physical activity, is the emotional wellbeing that accompanies the physical health improvement. Research has not focused on women post-menses in this regard, and the existing science has preferred investigations of low intensity, aerobic type exercise. Our research engaged women, post-menses, in a high frequency, high intensity resistance training programme for 12 weeks in a supervised setting. Apart from clinical health benefits, the participants reported feeling empowered by the intervention. This paper will argue that the predominating research focus has tended to reduce choices for women, and thus restrict independence, individuality and self-confidence.
- Full Text:
Restricted physical activity research in older women: does this represent additional risk to health?
- Authors: Viljoen, Janet E , Christie, Candice J
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143682 , vital:38273 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Post-menopausal women are at great risk of developing cardiovascular disease due to the loss of endogenous estrogen at menopause. This risk can be mediated via medication, but this route is costly and carries the risk of side effects which can reduce quality of life experience. The benefit of a lifestyle management approach to such risk, particularly via physical activity, is the emotional wellbeing that accompanies the physical health improvement. Research has not focused on women post-menses in this regard, and the existing science has preferred investigations of low intensity, aerobic type exercise. Our research engaged women, post-menses, in a high frequency, high intensity resistance training programme for 12 weeks in a supervised setting. Apart from clinical health benefits, the participants reported feeling empowered by the intervention. This paper will argue that the predominating research focus has tended to reduce choices for women, and thus restrict independence, individuality and self-confidence.
- Full Text:
'Feeling at home': institutional culture and the idea of a university
- Authors: Vice, Samantha
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142072 , vital:38047 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
- Authors: Vice, Samantha
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142072 , vital:38047 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
Facile synthesis and biological evaluation of assorted indolyl-3-amides and esters from a single, stable carbonyl nitrile intermediate
- Veale, Clinton G L, Edkins, Adrienne L, de la Mare, Jo-Anne, de Kock, Carmen, Smith, Peter J, Khanye, Setshaba D
- Authors: Veale, Clinton G L , Edkins, Adrienne L , de la Mare, Jo-Anne , de Kock, Carmen , Smith, Peter J , Khanye, Setshaba D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66221 , vital:28919 , https://doi.org/10.1016/j.tetlet.2015.02.090
- Description: publisher version , The synthesis of biologically relevant amides and esters is routinely conducted under complex reaction conditions or requires the use of additional catalysts in order to generate sensitive electrophilic species for attack by a nucleophile. Here we present the synthesis of different indolic esters and amides from indolyl-3-carbonyl nitrile, without the requirement of anhydrous reaction conditions or catalysts. Additionally, we screened these compounds for potential in vitro antimalarial and anticancer activity, revealing 1H-indolyl-3-carboxylic acid 3-(indolyl-3-carboxamide)aminobenzyl ester to have moderate activity against both lines.
- Full Text: false
- Authors: Veale, Clinton G L , Edkins, Adrienne L , de la Mare, Jo-Anne , de Kock, Carmen , Smith, Peter J , Khanye, Setshaba D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66221 , vital:28919 , https://doi.org/10.1016/j.tetlet.2015.02.090
- Description: publisher version , The synthesis of biologically relevant amides and esters is routinely conducted under complex reaction conditions or requires the use of additional catalysts in order to generate sensitive electrophilic species for attack by a nucleophile. Here we present the synthesis of different indolic esters and amides from indolyl-3-carbonyl nitrile, without the requirement of anhydrous reaction conditions or catalysts. Additionally, we screened these compounds for potential in vitro antimalarial and anticancer activity, revealing 1H-indolyl-3-carboxylic acid 3-(indolyl-3-carboxamide)aminobenzyl ester to have moderate activity against both lines.
- Full Text: false
A review of current DNS TTL practices
- Van Zyl, Ignus, Rudman, Lauren, Irwin, Barry V W
- Authors: Van Zyl, Ignus , Rudman, Lauren , Irwin, Barry V W
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427813 , vital:72464 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622760_A_review_of_current_DNS_TTL_practices/links/5b9a16e292851c4ba8181b7f/A-review-of-current-DNS-TTL-practices.pdf
- Description: This paper provides insight into legitimate DNS domain Time to Live (TTL) activity captured over two live caching servers from the period January to June 2014. DNS TTL practices are identified and compared between frequently queried domains, with respect to the caching servers. A breakdown of TTL practices by Resource Record type is also given, as well as an analysis on the TTL choices of the most frequent Top Level Domains. An analysis of anomalous TTL values with respect to the gathered data is also presented.
- Full Text:
- Authors: Van Zyl, Ignus , Rudman, Lauren , Irwin, Barry V W
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427813 , vital:72464 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622760_A_review_of_current_DNS_TTL_practices/links/5b9a16e292851c4ba8181b7f/A-review-of-current-DNS-TTL-practices.pdf
- Description: This paper provides insight into legitimate DNS domain Time to Live (TTL) activity captured over two live caching servers from the period January to June 2014. DNS TTL practices are identified and compared between frequently queried domains, with respect to the caching servers. A breakdown of TTL practices by Resource Record type is also given, as well as an analysis on the TTL choices of the most frequent Top Level Domains. An analysis of anomalous TTL values with respect to the gathered data is also presented.
- Full Text:
Back to the future: revival, relevance and route of an anarchist/syndicalist approach for twenty-first-century left, labour and national liberation movements
- Authors: van der Walt, Lucien
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144812 , vital:38381 , DOI: 10.1080/02589001.2016.1235365
- Description: The failings of classical Marxism, social democracy and anti-imperialist nationalism point to the need for a radical left politics at a distance from the state. This paper examines the impact, revival and promise of the anarchist/syndicalist tradition, a rich, continuous praxis in labour, left, anti-imperialist, anti-racist and egalitarian movements, worldwide, since the 1860s. Outlining its core ideas – anti-hierarchy, anti-capitalism, anti-statism, opposition to social and economic inequality, internationalist class-based mobilisation – and critique of mainstream Marxism and nationalism, it highlights the arguments there is a basic incompatibility between state rule, and bottom-up, egalitarian, democratic, socialist relationships. The anarchist/syndicalist project cannot be reduced to an organising style, protest politics or spontaneism: for it, transition to a just, self-managed society requires organised popular capacity for a revolutionary rupture, developed through prefigurative, class-based, democratic organs of counter-power, including syndicalist unions aiming at collectivised property, and revolutionary counter-culture. Success needs formal organisation, unified strategy and anarchist / syndicalist political organisations.
- Full Text:
- Authors: van der Walt, Lucien
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144812 , vital:38381 , DOI: 10.1080/02589001.2016.1235365
- Description: The failings of classical Marxism, social democracy and anti-imperialist nationalism point to the need for a radical left politics at a distance from the state. This paper examines the impact, revival and promise of the anarchist/syndicalist tradition, a rich, continuous praxis in labour, left, anti-imperialist, anti-racist and egalitarian movements, worldwide, since the 1860s. Outlining its core ideas – anti-hierarchy, anti-capitalism, anti-statism, opposition to social and economic inequality, internationalist class-based mobilisation – and critique of mainstream Marxism and nationalism, it highlights the arguments there is a basic incompatibility between state rule, and bottom-up, egalitarian, democratic, socialist relationships. The anarchist/syndicalist project cannot be reduced to an organising style, protest politics or spontaneism: for it, transition to a just, self-managed society requires organised popular capacity for a revolutionary rupture, developed through prefigurative, class-based, democratic organs of counter-power, including syndicalist unions aiming at collectivised property, and revolutionary counter-culture. Success needs formal organisation, unified strategy and anarchist / syndicalist political organisations.
- Full Text: