Evaluating the multi-threading countermeasure
- Frieslaar, Ibrahim, Irwin, Barry V W
- Authors: Frieslaar, Ibrahim , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428352 , vital:72505 , https://researchspace.csir.co.za/dspace/bitstream/handle/10204/9041/Frieslaar_2016.pdf?sequence=1andisAllowed=y
- Description: This research investigates the resistance of the multi-threaded coun-termeasure to side channel analysis (SCA) attacks. The multi-threaded countermeasure is attacked using the Correlation Power Analysis (CPA) and template attacks. Additionally, it is compared to the existing hiding countermeasure. Furthermore, additional signal processing techniques are used to increase the attack success ratio. It is demon-strated that the multi-threaded countermeasure is able to outperform the existing countermeasures by withstanding the CPA and template at-tacks. Furthermore, the multi-threaded countermeasure is unaffected by the elastic alignment and filtering techniques as opposed to the existing countermeasures. The research concludes that the multithreaded coun-termeasure is indeed a secure implementation to mitigate SCA attacks.
- Full Text:
- Authors: Frieslaar, Ibrahim , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428352 , vital:72505 , https://researchspace.csir.co.za/dspace/bitstream/handle/10204/9041/Frieslaar_2016.pdf?sequence=1andisAllowed=y
- Description: This research investigates the resistance of the multi-threaded coun-termeasure to side channel analysis (SCA) attacks. The multi-threaded countermeasure is attacked using the Correlation Power Analysis (CPA) and template attacks. Additionally, it is compared to the existing hiding countermeasure. Furthermore, additional signal processing techniques are used to increase the attack success ratio. It is demon-strated that the multi-threaded countermeasure is able to outperform the existing countermeasures by withstanding the CPA and template at-tacks. Furthermore, the multi-threaded countermeasure is unaffected by the elastic alignment and filtering techniques as opposed to the existing countermeasures. The research concludes that the multithreaded coun-termeasure is indeed a secure implementation to mitigate SCA attacks.
- Full Text:
Fat in a time of slim: the reinscription of race in the framing of fat desirability in post-apartheid South Africa
- Authors: Vincent, Louise
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141591 , vital:37988 , DOI: 10.1177/1363460716640730
- Description: This article critically examines the way in which the reported sexual desire of black African men for fat women is contained and managed in South African media representations of fat. While sexual desire for fat women represents a potential challenge to the dominant framing of fat as diseased/dysfunctional/disgusting, the article shows how the reduction of this desire to one of two (racialized) ‘explanations’ – either evidence of racial primitivism or a (black male) strategy to avoid infection with HIV – emasculates the potentially powerful oppositional framing of fat as sexy. It is a mark of the dominant frame’s influence that it is capable of co-opting oppositional frames and recasting them in its own image. From the point of view of critiques of the fat-as-disease orthodoxy, the claim to the existence of an alternative norm of fat as sexually desirable in ‘black culture’ emerges as a problematic oppositional frame – saturated with raced assumptions in the way in which it is reported. The counter framing of the (black) fat body as sexually desirable is given column space to be derided and dismissed as an instance of deviant black sexuality, as a mistaken belief in need of ‘correction’, or it is subsumed under a medicalized frame as a strategy for the avoidance of disease rather than an expression of genuine sexual desire.
- Full Text:
- Authors: Vincent, Louise
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141591 , vital:37988 , DOI: 10.1177/1363460716640730
- Description: This article critically examines the way in which the reported sexual desire of black African men for fat women is contained and managed in South African media representations of fat. While sexual desire for fat women represents a potential challenge to the dominant framing of fat as diseased/dysfunctional/disgusting, the article shows how the reduction of this desire to one of two (racialized) ‘explanations’ – either evidence of racial primitivism or a (black male) strategy to avoid infection with HIV – emasculates the potentially powerful oppositional framing of fat as sexy. It is a mark of the dominant frame’s influence that it is capable of co-opting oppositional frames and recasting them in its own image. From the point of view of critiques of the fat-as-disease orthodoxy, the claim to the existence of an alternative norm of fat as sexually desirable in ‘black culture’ emerges as a problematic oppositional frame – saturated with raced assumptions in the way in which it is reported. The counter framing of the (black) fat body as sexually desirable is given column space to be derided and dismissed as an instance of deviant black sexuality, as a mistaken belief in need of ‘correction’, or it is subsumed under a medicalized frame as a strategy for the avoidance of disease rather than an expression of genuine sexual desire.
- Full Text:
Festival fringe production and the long tail
- Authors: Snowball, Jeanette D
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68855 , vital:29332 , http://www.econrsa.org/node/1170
- Description: Publisher version , In the past 15 years, there has been a worldwide proliferation of arts festivals, including so-called "fringe" festivals, which encouraged more experimental and avant-garde productions. While fringe festival productions had the potential to generate significant income for producers, their aims were primarily related to artistic innovation and it is well known that putting on a fringe show is highly unlikely to provide financial gain for most producers. This is what is referred to in statistics and marketing as a "long tail" distribution, in which a minority of producers in a particular market earn the vast majority of industry income. However, for individual producers of live theatre, such a distribution represents high risks and potentially large financial losses. This article uses producer data from two different fringe festivals in South Africa to explore determinants of ticket sales and box-office income. Included in the analysis is a consideration of the impact of genre and pricing strategies on the probability (Logit model) of shows being in the top 10%, 30% and 50% of best-selling and earning productions. Results support the long tail hypothesis.
- Full Text:
- Authors: Snowball, Jeanette D
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68855 , vital:29332 , http://www.econrsa.org/node/1170
- Description: Publisher version , In the past 15 years, there has been a worldwide proliferation of arts festivals, including so-called "fringe" festivals, which encouraged more experimental and avant-garde productions. While fringe festival productions had the potential to generate significant income for producers, their aims were primarily related to artistic innovation and it is well known that putting on a fringe show is highly unlikely to provide financial gain for most producers. This is what is referred to in statistics and marketing as a "long tail" distribution, in which a minority of producers in a particular market earn the vast majority of industry income. However, for individual producers of live theatre, such a distribution represents high risks and potentially large financial losses. This article uses producer data from two different fringe festivals in South Africa to explore determinants of ticket sales and box-office income. Included in the analysis is a consideration of the impact of genre and pricing strategies on the probability (Logit model) of shows being in the top 10%, 30% and 50% of best-selling and earning productions. Results support the long tail hypothesis.
- Full Text:
Fluorescence behavior of nanoconjugates of graphene quantum dots and zinc phthalocyanines
- Achadu, Ojodomo John, Uddin, Imran, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188777 , vital:44784 , xlink:href="https://doi.org/10.1016/j.jphotochem.2015.11.006"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanines interactions in different modes (covalent and non-covalent) are reported in this study. GQDs were covalently attached to the following complexes: zinc tetraamino phthalocyanine (ZnTAPc) via amide coupling, zinc tetracarboxyphenoxy Pc (ZnTCPPc) (π–π interaction) and cationic zinc tetrapyridiloxy Pc (ZnTmPyPc) (ionic interaction). GQDs fluorescence was quenched in the presence of the ZnPc derivatives. The nanoensembles of GQDs–ZnPcs showed stimulated emissions of the ZnPcs. The suggested quenching mechanism is through Förster resonance energy transfer (FRET). These novel nanoensembles hold promise for various optical and luminescence based applications.
- Full Text:
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188777 , vital:44784 , xlink:href="https://doi.org/10.1016/j.jphotochem.2015.11.006"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanines interactions in different modes (covalent and non-covalent) are reported in this study. GQDs were covalently attached to the following complexes: zinc tetraamino phthalocyanine (ZnTAPc) via amide coupling, zinc tetracarboxyphenoxy Pc (ZnTCPPc) (π–π interaction) and cationic zinc tetrapyridiloxy Pc (ZnTmPyPc) (ionic interaction). GQDs fluorescence was quenched in the presence of the ZnPc derivatives. The nanoensembles of GQDs–ZnPcs showed stimulated emissions of the ZnPcs. The suggested quenching mechanism is through Förster resonance energy transfer (FRET). These novel nanoensembles hold promise for various optical and luminescence based applications.
- Full Text:
Fluorescence properties of alloyed ZnSeS quantum dots overcoated with ZnTe and ZnTe/ZnS shells
- Adegoke, Oluwasesan, Mashazi, Philani N, Nyokong, Tebello, Forbes, Patricia B C
- Authors: Adegoke, Oluwasesan , Mashazi, Philani N , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240754 , vital:50868 , xlink:href="https://doi.org/10.1016/j.optmat.2016.02.024"
- Description: Fluorescent alloyed ternary ZnSeS quantum dots (QDs) have been synthesized via the pyrolysis of organometallic precursors. The effects of passivation of ZnTe and ZnTe/ZnS shells on the optical properties of the ternary alloyed ZnSeS core have been studied. A ligand exchange reaction using L-cysteine as a capping ligand was used to obtain water-soluble nanocrystals. The nanocrystals were each characterized by UV/vis absorption and fluorescence spectroscopy, transmission electron microscopy, X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The photoluminescence (PL) quantum yield (QY) of alloyed ZnSeS QDs was 14% and this value increased to 27% when ZnTe was overcoated around the surface but further coating with a ZnS shell decreased the PL QY slightly to 24%. This implies that ZnTe shell suppressed non-radiative recombination exciton states in the alloyed core while further layering with a ZnS shell offered no further improvement in suppressing the defect states. XPS analysis confirmed the presence of the first shell layering but showed a weakened intensity signal of S (2p) and Se (3d) for the ZnSeS/ZnTe/ZnS QDs. Our work demonstrates for the first time that shell passivation of alloyed Zn-based QDs can offer improved optical properties. We hope the optical information presented in this work will be useful in the selection of alloyed Zn-based QDs appropriate for the intended application.
- Full Text:
- Authors: Adegoke, Oluwasesan , Mashazi, Philani N , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240754 , vital:50868 , xlink:href="https://doi.org/10.1016/j.optmat.2016.02.024"
- Description: Fluorescent alloyed ternary ZnSeS quantum dots (QDs) have been synthesized via the pyrolysis of organometallic precursors. The effects of passivation of ZnTe and ZnTe/ZnS shells on the optical properties of the ternary alloyed ZnSeS core have been studied. A ligand exchange reaction using L-cysteine as a capping ligand was used to obtain water-soluble nanocrystals. The nanocrystals were each characterized by UV/vis absorption and fluorescence spectroscopy, transmission electron microscopy, X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The photoluminescence (PL) quantum yield (QY) of alloyed ZnSeS QDs was 14% and this value increased to 27% when ZnTe was overcoated around the surface but further coating with a ZnS shell decreased the PL QY slightly to 24%. This implies that ZnTe shell suppressed non-radiative recombination exciton states in the alloyed core while further layering with a ZnS shell offered no further improvement in suppressing the defect states. XPS analysis confirmed the presence of the first shell layering but showed a weakened intensity signal of S (2p) and Se (3d) for the ZnSeS/ZnTe/ZnS QDs. Our work demonstrates for the first time that shell passivation of alloyed Zn-based QDs can offer improved optical properties. We hope the optical information presented in this work will be useful in the selection of alloyed Zn-based QDs appropriate for the intended application.
- Full Text:
From global to regional and back again: common climate stressors of marine ecosystems relevant for adaptation across five ocean warming hotspots
- Popova, Ekaterina, Yool, Andrew, Byfield, Valborg, Cochrane, Kevern, Coward, Andrew C, Salim, Shyam S, Gasalla, Maria A, Henson, S.A, Hobday, Alistair J, Pecl, Gretta T, Sauer, Warwick H H, Roberts, Michael J
- Authors: Popova, Ekaterina , Yool, Andrew , Byfield, Valborg , Cochrane, Kevern , Coward, Andrew C , Salim, Shyam S , Gasalla, Maria A , Henson, S.A , Hobday, Alistair J , Pecl, Gretta T , Sauer, Warwick H H , Roberts, Michael J
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124514 , vital:35623 , https://doi.10.1111/gcb.13247
- Description: Ocean warming ‘hotspots’ are regions characterized by above-average temperature increases over recent years, for which there are significant consequences for both living marine resources and the societies that depend on them. As such, they represent early warning systems for understanding the impacts of marine climate change, and test-beds for developing adaptation options for coping with those impacts. Here, we examine five hotspots off the coasts of eastern Australia, South Africa, Madagascar, India and Brazil. These particular hotspots have underpinned a large international partnership that is working towards improving community adaptation by characterizing, assessing and projecting the likely future of coastal-marine food resources through the provision and sharing of knowledge. To inform this effort, we employ a high-resolution global ocean model forced by Representative Concentration Pathway 8.5 and simulated to year 2099. In addition to the sea surface temperature, we analyse projected stratification, nutrient supply, primary production, anthropogenic CO2-driven ocean acidification, deoxygenation and ocean circulation. Our simulation finds that the temperature-defined hotspots studied here will continue to experience warming but, with the exception of eastern Australia, may not remain the fastest warming ocean areas over the next century as the strongest warming is projected to occur in the subpolar and polar areas of the Northern Hemisphere. Additionally, we find that recent rapid change in SST is not necessarily an indicator that these areas are also hotspots of the other climatic stressors examined. However, a consistent facet of the hotspots studied here is that they are all strongly influenced by ocean circulation, which has already shown changes in the recent past and is projected to undergo further strong change into the future. In addition to the fast warming, change in local ocean circulation represents a distinct feature of present and future climate change impacting marine ecosystems in these areas.
- Full Text:
- Authors: Popova, Ekaterina , Yool, Andrew , Byfield, Valborg , Cochrane, Kevern , Coward, Andrew C , Salim, Shyam S , Gasalla, Maria A , Henson, S.A , Hobday, Alistair J , Pecl, Gretta T , Sauer, Warwick H H , Roberts, Michael J
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124514 , vital:35623 , https://doi.10.1111/gcb.13247
- Description: Ocean warming ‘hotspots’ are regions characterized by above-average temperature increases over recent years, for which there are significant consequences for both living marine resources and the societies that depend on them. As such, they represent early warning systems for understanding the impacts of marine climate change, and test-beds for developing adaptation options for coping with those impacts. Here, we examine five hotspots off the coasts of eastern Australia, South Africa, Madagascar, India and Brazil. These particular hotspots have underpinned a large international partnership that is working towards improving community adaptation by characterizing, assessing and projecting the likely future of coastal-marine food resources through the provision and sharing of knowledge. To inform this effort, we employ a high-resolution global ocean model forced by Representative Concentration Pathway 8.5 and simulated to year 2099. In addition to the sea surface temperature, we analyse projected stratification, nutrient supply, primary production, anthropogenic CO2-driven ocean acidification, deoxygenation and ocean circulation. Our simulation finds that the temperature-defined hotspots studied here will continue to experience warming but, with the exception of eastern Australia, may not remain the fastest warming ocean areas over the next century as the strongest warming is projected to occur in the subpolar and polar areas of the Northern Hemisphere. Additionally, we find that recent rapid change in SST is not necessarily an indicator that these areas are also hotspots of the other climatic stressors examined. However, a consistent facet of the hotspots studied here is that they are all strongly influenced by ocean circulation, which has already shown changes in the recent past and is projected to undergo further strong change into the future. In addition to the fast warming, change in local ocean circulation represents a distinct feature of present and future climate change impacting marine ecosystems in these areas.
- Full Text:
Geospatial technologies and indigenous Knowledge Systems:
- Authors: Aswani, Shankar
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/145448 , vital:38439 , ISBN 9781315181523 , https://www.taylorfrancis.com/books/e/9781315181523/chapters/10.1201/9781315181523-18
- Description: During the twentieth and twenty-first centuries, pressure on coastal ecosystems has amplified and resulted in the widespread degradation of adjacent marine and terrestrial habitats globally (Burke et al., 2001). The ecosystem services provided by coastal habitats, including coastal protection and food procurement, have been heavily compromised by anthropogenic disturbance such as overfishing, pollution, sedimentation and alteration of coastal vegetation (Costanza et al., 1997; Agardy et al., 2009). In the context of small islands, this continued degradation in tandem with the ongoing effects of climate change is putting the livelihoods of coastal peoples at risk (e.g. Bell et al., 2009). While international efforts at curtailing these negative trends are ongoing, many researchers are working directly with coastal local/ indigenous communities to seek more effective management of coastal terrestrial and marine resources. Among various approaches, researchers are increasingly incorporating local knowledge systems for designing resource management and conservation plans (e.g. Gadgil et al., 1993).
- Full Text:
- Authors: Aswani, Shankar
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/145448 , vital:38439 , ISBN 9781315181523 , https://www.taylorfrancis.com/books/e/9781315181523/chapters/10.1201/9781315181523-18
- Description: During the twentieth and twenty-first centuries, pressure on coastal ecosystems has amplified and resulted in the widespread degradation of adjacent marine and terrestrial habitats globally (Burke et al., 2001). The ecosystem services provided by coastal habitats, including coastal protection and food procurement, have been heavily compromised by anthropogenic disturbance such as overfishing, pollution, sedimentation and alteration of coastal vegetation (Costanza et al., 1997; Agardy et al., 2009). In the context of small islands, this continued degradation in tandem with the ongoing effects of climate change is putting the livelihoods of coastal peoples at risk (e.g. Bell et al., 2009). While international efforts at curtailing these negative trends are ongoing, many researchers are working directly with coastal local/ indigenous communities to seek more effective management of coastal terrestrial and marine resources. Among various approaches, researchers are increasingly incorporating local knowledge systems for designing resource management and conservation plans (e.g. Gadgil et al., 1993).
- Full Text:
Global proliferation of cephalopods
- Doubleday, Zoë A, Prowse, Thomas A A, Arkhipkin, Alexander, Pierce, Graham J, Semmens, Jayson, Steer, Michael, Leporati, Stephen C, Lourenço, Sílvia, Quetglas, Antoni, Sauer, Warwick H H, Gillanders, Bronwyn M
- Authors: Doubleday, Zoë A , Prowse, Thomas A A , Arkhipkin, Alexander , Pierce, Graham J , Semmens, Jayson , Steer, Michael , Leporati, Stephen C , Lourenço, Sílvia , Quetglas, Antoni , Sauer, Warwick H H , Gillanders, Bronwyn M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124560 , vital:35628 , https://doi.10.1016/j.cub.2016.04.002
- Description: Human activities have substantially changed the world’s oceans in recent decades, altering marine food webs, habitats and biogeochemical processes [1]. Cephalopods (squid, cuttlefish and octopuses) have a unique set of biological traits, including rapid growth, short lifespans and strong life-history plasticity, allowing them to adapt quickly to changing environmental conditions [2–4]. There has been growing speculation that cephalopod populations are proliferating in response to a changing environment, a perception fuelled by increasing trends in cephalopod fisheries catch [4,5]. To investigate long-term trends in cephalopod abundance, we assembled global time-series of cephalopod catch rates (catch per unit of fishing or sampling effort). We show that cephalopod populations have increased over the last six decades, a result that was remarkably consistent across a highly diverse set of cephalopod taxa. Positive trends were also evident for both fisheries-dependent and fisheries independent time-series, suggesting that trends are not solely due to factors associated with developing fisheries. Our results suggest that large-scale, directional processes, common to a range of coastal and oceanic environments, are responsible. This study presents the first evidence that cephalopod populations have increased globally, indicating that these ecologically and commercially important invertebrates may have benefited from a changing ocean environment.
- Full Text:
- Authors: Doubleday, Zoë A , Prowse, Thomas A A , Arkhipkin, Alexander , Pierce, Graham J , Semmens, Jayson , Steer, Michael , Leporati, Stephen C , Lourenço, Sílvia , Quetglas, Antoni , Sauer, Warwick H H , Gillanders, Bronwyn M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124560 , vital:35628 , https://doi.10.1016/j.cub.2016.04.002
- Description: Human activities have substantially changed the world’s oceans in recent decades, altering marine food webs, habitats and biogeochemical processes [1]. Cephalopods (squid, cuttlefish and octopuses) have a unique set of biological traits, including rapid growth, short lifespans and strong life-history plasticity, allowing them to adapt quickly to changing environmental conditions [2–4]. There has been growing speculation that cephalopod populations are proliferating in response to a changing environment, a perception fuelled by increasing trends in cephalopod fisheries catch [4,5]. To investigate long-term trends in cephalopod abundance, we assembled global time-series of cephalopod catch rates (catch per unit of fishing or sampling effort). We show that cephalopod populations have increased over the last six decades, a result that was remarkably consistent across a highly diverse set of cephalopod taxa. Positive trends were also evident for both fisheries-dependent and fisheries independent time-series, suggesting that trends are not solely due to factors associated with developing fisheries. Our results suggest that large-scale, directional processes, common to a range of coastal and oceanic environments, are responsible. This study presents the first evidence that cephalopod populations have increased globally, indicating that these ecologically and commercially important invertebrates may have benefited from a changing ocean environment.
- Full Text:
Gradient high performance liquid chromatographic method for the simultaneous analysis of efavirenz, emtricitabine and tenofovir
- Authors: Koekemoer, Sonya Mariana
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54679 , vital:26599
- Description: In 2014, approximately 6.8 million people in South Africa were HIV-positive, and the majority of those affected are aged 15 or older. A fixed-dose combination (FDC) antiretroviral (ARV) dosage form containing one non-nucleotide reverse transcriptase inhibitor (efavirenz) and two nucleotide reverse transcriptase inhibitors (emtricitabine and tenofovir) was licensed in South Africa in April 2013. New consolidated guidelines for HIV management and prevention of mother to child transmission (PMTCT) were published by the South African Department of Health in December 2014 and the FDC is now the recommended first-line treatment for HIV-positive patients. According to these guidelines all such people aged 15 and older, and weighing more than 40 kg, with a CD4 count of ≤ 500/ μl will be eligible for antiretroviral therapy (ART) using the FDC. In addition every pregnant and breastfeeding woman is eligible for lifelong ART regardless of CD4 count and EFV can be used as first-line treatment for pregnant women regardless of the length of gestation state of the pregnancy at that time. The use of this simplified regime is likely to promote much needed and improved adherence to therapy. An investigation into the development of a stability-indicating reversed-phase high performance liquid chromatography (RP-HPLC) method for the simultaneous quantitation of EFV, FTC and TNF was undertaken. Isocratic HPLC analysis was found to be unsuitable due to the highly polar FTC molecule eluting in the void. Therefore a gradient HPLC method was developed and validated. The method was validated according to the International Conference on Harmonisation, now known as International Council for Harmonization (ICH). Correlation coefficients > 0.999 were obtained for each assessment of linearity and FTC, TNF and EFV are linear in the range 0.4-40 μg/ml, 0.6-60 μg/ml and 1.2-120 μg/ml. The equation of the best-fit least squares regression lines for FTC, TNF and EFV were y = 0.0191x+0.0007, y = 0.0163x+0.0116 and y = 0.01x+0.016, respectively. The method is accurate as the y-intercept was < 2% of the detector response for all ARV, and the method is precise in terms of intra- and inter-assay precision as all % RSD < 2%. The stability-indicating nature of the method was demonstrated under acidic, alkaline and oxidative stress in addition to UV exposure and elevated temperatures, and the individual chromatograms were overlaid using Empower® 3 Software to establish whether there was interference with the peaks of interest. The forced degradation studies demonstrated the selectivity of the method for the ARV compounds. The method was applied to assay and in vitro dissolution studies of commercially available tablets. The amount of each active ingredient released from Atripla® was determined and compared to the amount of each drug released from Aspen Efavirenz® and Truvada® (a combination of FTC and TNF). The percent FTC released from Atripla® and Truvada® was similar based on the acceptance criteria for immediate-release BCS class 1 compounds. Statistical analysis was undertaken to compare the dissolution profiles of FTC, TNF and EFV. The percent of these compounds released in these studies indicate that bioequivalence testing would be required to declare these products interchangeable. The validated RP-HPLC and in vitro dissolution test method are suitable for routine quality control testing of solid oral dosage forms containing EFV, FTC and TNF, and as the dissolution method can discriminate between different formulations of the same molecule, these tools can also be used for analysis during formulation development studies. The method is not suitable for the analysis of the ARV plasma due to lack of sensitivity and an inability to quantitate the compounds at the required concentration levels. The use of HPLC with mass spectroscopy for quantitation would enhance the sensitivity of the method and may eliminate the quantitation of the molecules in the presence of interference that was observed when using UV detection. Fixed dose combination tablets are convenient for patient therapy and it is likely that in the future more molecules will be formulated into such dosage forms. However formulations such as these can pose significant difficulties when developing and using analytical methods for the quantitation of all compounds in the dosage form at the same time, in particular when the compounds have vastly different physico-chemical properties that impact the quality of a separation and therefore the analysis. Therefore when embarking on the development of FDC product cognisance of the difficulties of developing single methods for the analyses is required and approaches to overcome these difficulties should be considered.
- Full Text:
- Authors: Koekemoer, Sonya Mariana
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54679 , vital:26599
- Description: In 2014, approximately 6.8 million people in South Africa were HIV-positive, and the majority of those affected are aged 15 or older. A fixed-dose combination (FDC) antiretroviral (ARV) dosage form containing one non-nucleotide reverse transcriptase inhibitor (efavirenz) and two nucleotide reverse transcriptase inhibitors (emtricitabine and tenofovir) was licensed in South Africa in April 2013. New consolidated guidelines for HIV management and prevention of mother to child transmission (PMTCT) were published by the South African Department of Health in December 2014 and the FDC is now the recommended first-line treatment for HIV-positive patients. According to these guidelines all such people aged 15 and older, and weighing more than 40 kg, with a CD4 count of ≤ 500/ μl will be eligible for antiretroviral therapy (ART) using the FDC. In addition every pregnant and breastfeeding woman is eligible for lifelong ART regardless of CD4 count and EFV can be used as first-line treatment for pregnant women regardless of the length of gestation state of the pregnancy at that time. The use of this simplified regime is likely to promote much needed and improved adherence to therapy. An investigation into the development of a stability-indicating reversed-phase high performance liquid chromatography (RP-HPLC) method for the simultaneous quantitation of EFV, FTC and TNF was undertaken. Isocratic HPLC analysis was found to be unsuitable due to the highly polar FTC molecule eluting in the void. Therefore a gradient HPLC method was developed and validated. The method was validated according to the International Conference on Harmonisation, now known as International Council for Harmonization (ICH). Correlation coefficients > 0.999 were obtained for each assessment of linearity and FTC, TNF and EFV are linear in the range 0.4-40 μg/ml, 0.6-60 μg/ml and 1.2-120 μg/ml. The equation of the best-fit least squares regression lines for FTC, TNF and EFV were y = 0.0191x+0.0007, y = 0.0163x+0.0116 and y = 0.01x+0.016, respectively. The method is accurate as the y-intercept was < 2% of the detector response for all ARV, and the method is precise in terms of intra- and inter-assay precision as all % RSD < 2%. The stability-indicating nature of the method was demonstrated under acidic, alkaline and oxidative stress in addition to UV exposure and elevated temperatures, and the individual chromatograms were overlaid using Empower® 3 Software to establish whether there was interference with the peaks of interest. The forced degradation studies demonstrated the selectivity of the method for the ARV compounds. The method was applied to assay and in vitro dissolution studies of commercially available tablets. The amount of each active ingredient released from Atripla® was determined and compared to the amount of each drug released from Aspen Efavirenz® and Truvada® (a combination of FTC and TNF). The percent FTC released from Atripla® and Truvada® was similar based on the acceptance criteria for immediate-release BCS class 1 compounds. Statistical analysis was undertaken to compare the dissolution profiles of FTC, TNF and EFV. The percent of these compounds released in these studies indicate that bioequivalence testing would be required to declare these products interchangeable. The validated RP-HPLC and in vitro dissolution test method are suitable for routine quality control testing of solid oral dosage forms containing EFV, FTC and TNF, and as the dissolution method can discriminate between different formulations of the same molecule, these tools can also be used for analysis during formulation development studies. The method is not suitable for the analysis of the ARV plasma due to lack of sensitivity and an inability to quantitate the compounds at the required concentration levels. The use of HPLC with mass spectroscopy for quantitation would enhance the sensitivity of the method and may eliminate the quantitation of the molecules in the presence of interference that was observed when using UV detection. Fixed dose combination tablets are convenient for patient therapy and it is likely that in the future more molecules will be formulated into such dosage forms. However formulations such as these can pose significant difficulties when developing and using analytical methods for the quantitation of all compounds in the dosage form at the same time, in particular when the compounds have vastly different physico-chemical properties that impact the quality of a separation and therefore the analysis. Therefore when embarking on the development of FDC product cognisance of the difficulties of developing single methods for the analyses is required and approaches to overcome these difficulties should be considered.
- Full Text:
Graphene quantum dots functionalized with 4-amino-2, 2, 6, 6-tetramethylpiperidine-N-oxide as fluorescence “turn-on” nanosensors
- Achadu, Ojodomo J, Britton, Jonathan, Nyokong, Tebello
- Authors: Achadu, Ojodomo J , Britton, Jonathan , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239854 , vital:50773 , xlink:href="https://doi.org/10.1007/s10895-016-1916-y"
- Description: In this study, we report on the fabrication of simple and rapid graphene quantum dots (GQDs)-based fluorescence “turn-ON” nanoprobes for sensitive and selective detection of ascorbic acid (AA). Pristine GQDs and S and N co-doped-GQDs (SN-GQDs) were functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4-amino-TEMPO, a nitroxide free radical). The nitroxide free radicals efficiently quenched the fluorescence of the GQDs and upon interaction of the nanoconjugates with ascorbic acid, the quenched fluorescence was restored. The linear ranges recorded were 0.5–5.7 μM and 0.1–5.5 μM for GQDs-4-amino-TEMPO and SN-GQDs-4amino-TEMPO nanoprobes, respectively. Limits of detection were found to be 60 nM and 84 nM for SN-GQDS-4-amino-TEMPO and GQDs-4-amino-TEMPO for AA detection, respectively. This novel fluorescence “turn-ON” technique showed to be highly rapid and selective towards AA detection.
- Full Text:
- Authors: Achadu, Ojodomo J , Britton, Jonathan , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239854 , vital:50773 , xlink:href="https://doi.org/10.1007/s10895-016-1916-y"
- Description: In this study, we report on the fabrication of simple and rapid graphene quantum dots (GQDs)-based fluorescence “turn-ON” nanoprobes for sensitive and selective detection of ascorbic acid (AA). Pristine GQDs and S and N co-doped-GQDs (SN-GQDs) were functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4-amino-TEMPO, a nitroxide free radical). The nitroxide free radicals efficiently quenched the fluorescence of the GQDs and upon interaction of the nanoconjugates with ascorbic acid, the quenched fluorescence was restored. The linear ranges recorded were 0.5–5.7 μM and 0.1–5.5 μM for GQDs-4-amino-TEMPO and SN-GQDs-4amino-TEMPO nanoprobes, respectively. Limits of detection were found to be 60 nM and 84 nM for SN-GQDS-4-amino-TEMPO and GQDs-4-amino-TEMPO for AA detection, respectively. This novel fluorescence “turn-ON” technique showed to be highly rapid and selective towards AA detection.
- Full Text:
HealthMessenger: an e-Health service to support ICT deployments in poor areas
- Gremu, Chikumbutso, Terzoli, Alfredo, Tsietsi, Mosiuoa
- Authors: Gremu, Chikumbutso , Terzoli, Alfredo , Tsietsi, Mosiuoa
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430609 , vital:72703 , 10.1109/ISTAFRICA.2016.7530632
- Description: Development and implementation of appropriate e-services as well as revenue generation are key to deploying and sustaining ICT installa-tions in poor areas in developing countries. The area of e-Health is a promising area for e-Services that are important to populations in poor areas and health service organisations that are already spending mon-ey on different health initiatives in these areas. This paper discusses an e-Health service that facilitates dissemination of health information to people living in poor areas and that is subsequently used to generate revenue to support deployment and development of ICT in the areas. The tool was developed within the context of the Siyakhula Living Lab (SLL), a multi-stakeholder operation that promotes ICT for Development in the Eastern Cape Province of South Africa. Creation of health con-tent for the e-health service and its subsequent consumption happen in two different environments from a technological and social point of view. To enable this to happen, the e-service comprises two component applications that run in a peer-to-peer fashion. The component that is used to disseminate content for end-user consumption is called the HealthMessenger. The HealthMessenger is hosted on an environment called TeleWeaver, an application integration platform developed within the SLL to host software applications targeting people living in poor ar-eas. The platform is customised to support services with a revenue generation component.
- Full Text:
- Authors: Gremu, Chikumbutso , Terzoli, Alfredo , Tsietsi, Mosiuoa
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430609 , vital:72703 , 10.1109/ISTAFRICA.2016.7530632
- Description: Development and implementation of appropriate e-services as well as revenue generation are key to deploying and sustaining ICT installa-tions in poor areas in developing countries. The area of e-Health is a promising area for e-Services that are important to populations in poor areas and health service organisations that are already spending mon-ey on different health initiatives in these areas. This paper discusses an e-Health service that facilitates dissemination of health information to people living in poor areas and that is subsequently used to generate revenue to support deployment and development of ICT in the areas. The tool was developed within the context of the Siyakhula Living Lab (SLL), a multi-stakeholder operation that promotes ICT for Development in the Eastern Cape Province of South Africa. Creation of health con-tent for the e-health service and its subsequent consumption happen in two different environments from a technological and social point of view. To enable this to happen, the e-service comprises two component applications that run in a peer-to-peer fashion. The component that is used to disseminate content for end-user consumption is called the HealthMessenger. The HealthMessenger is hosted on an environment called TeleWeaver, an application integration platform developed within the SLL to host software applications targeting people living in poor ar-eas. The platform is customised to support services with a revenue generation component.
- Full Text:
Heterogeneity in virulence relationships between Cryptophlebia leucotreta granulovirus isolates and geographically distinct host populations: Lessons from codling moth resistance to CpGV-M
- Opoku-Debrah, John K, Hill, Martin P, Knox, Caroline M, Moore, Sean D
- Authors: Opoku-Debrah, John K , Hill, Martin P , Knox, Caroline M , Moore, Sean D
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417998 , vital:71500 , xlink:href="https://doi.org/10.1007/s10526-016-9728-1"
- Description: In South Africa, the baculovirus Cryptophlebia leucotreta granulovirus (CrleGV) is used to control the citrus pest Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). However, the risk associated with continuous application of a single active ingredient is resistance. In order to manage resistance should it occur in field populations of T. leucotreta in South Africa, five new CrleGV genotypes from geographically distinct insect populations which were shown to exhibit some degree of phenotypic variation were recovered and genetically characterized. In droplet bioassays using seven CrleGV isolates against five T. leucotreta populations, some isolates were found to show higher virulence to some host populations than others. There were marked differences in the LD50 values of isolates and the number of occlusion bodies required per larva ranged between 0.79 and 3.12. The significance of these findings with respect to the application of CrleGV biopesticides and the management of resistance is discussed.
- Full Text:
- Authors: Opoku-Debrah, John K , Hill, Martin P , Knox, Caroline M , Moore, Sean D
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417998 , vital:71500 , xlink:href="https://doi.org/10.1007/s10526-016-9728-1"
- Description: In South Africa, the baculovirus Cryptophlebia leucotreta granulovirus (CrleGV) is used to control the citrus pest Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). However, the risk associated with continuous application of a single active ingredient is resistance. In order to manage resistance should it occur in field populations of T. leucotreta in South Africa, five new CrleGV genotypes from geographically distinct insect populations which were shown to exhibit some degree of phenotypic variation were recovered and genetically characterized. In droplet bioassays using seven CrleGV isolates against five T. leucotreta populations, some isolates were found to show higher virulence to some host populations than others. There were marked differences in the LD50 values of isolates and the number of occlusion bodies required per larva ranged between 0.79 and 3.12. The significance of these findings with respect to the application of CrleGV biopesticides and the management of resistance is discussed.
- Full Text:
Ideas of poetic form: aspects of the Romantic-Symbolist tradition
- Authors: Oldert, David
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/54554 , vital:26587
- Description: The subject of the work is some of the formal and technical developments of modern poetry in the Romantic-Symbolist tradition. These developments were stimulated partly by the ideas of the non-intellectual Symbol inherited from the Romantics and the idea that poetry could be a musical medium inherited from some of the French Symbolists. Their combined influence led to a number of technical problems in the structuring of imagery and the handling of syntax. The work begins, therefore, by tracing the philosophical assumptions behind the ideas of the Symbol and of the musical analogy. I then go on to examine two of the difficulties that these ideas produced. One is the tension between the analogical structure of a poem’s imagery and its metaphorical texture: quite simply, the more compressed and complex a poet’s metaphors become, the more they tend to disrupt the poem’s structure of imagery. The other problem is obscurity, which is caused by insufficient objectification of private images in a symbolic structure, and by fused metaphor, which is essentially a metaphor with an obscured ground of resemblance. Finally, I show how these difficulties were solved by poets outside the tradition who used a more articulate kind of syntax, yet who also managed to combine that syntax with the ideal of symbolic form. The implicit argument, then, is that the Romantic-Symbolist ideas of form, and the New Critics’ theories of form which were largely based on them, are able to elucidate an essentially different kind of poetry, and thus have some degree of truth and use beyond the tradition that generated them.
- Full Text:
- Authors: Oldert, David
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/54554 , vital:26587
- Description: The subject of the work is some of the formal and technical developments of modern poetry in the Romantic-Symbolist tradition. These developments were stimulated partly by the ideas of the non-intellectual Symbol inherited from the Romantics and the idea that poetry could be a musical medium inherited from some of the French Symbolists. Their combined influence led to a number of technical problems in the structuring of imagery and the handling of syntax. The work begins, therefore, by tracing the philosophical assumptions behind the ideas of the Symbol and of the musical analogy. I then go on to examine two of the difficulties that these ideas produced. One is the tension between the analogical structure of a poem’s imagery and its metaphorical texture: quite simply, the more compressed and complex a poet’s metaphors become, the more they tend to disrupt the poem’s structure of imagery. The other problem is obscurity, which is caused by insufficient objectification of private images in a symbolic structure, and by fused metaphor, which is essentially a metaphor with an obscured ground of resemblance. Finally, I show how these difficulties were solved by poets outside the tradition who used a more articulate kind of syntax, yet who also managed to combine that syntax with the ideal of symbolic form. The implicit argument, then, is that the Romantic-Symbolist ideas of form, and the New Critics’ theories of form which were largely based on them, are able to elucidate an essentially different kind of poetry, and thus have some degree of truth and use beyond the tradition that generated them.
- Full Text:
Identification of potential novel roles for Hsp70/Hsp90 organising protein (Hop) using proteomic analysis in human cells
- Authors: Wingate, Ianthe
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64758 , vital:28598
- Description: Expected release date-May 2018
- Full Text:
- Authors: Wingate, Ianthe
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64758 , vital:28598
- Description: Expected release date-May 2018
- Full Text:
Impacts of HIV/AIDS on food consumption and wild food use in rural South Africa
- Ncube, Keitometsi, Shackleton, Charlie M, Swallow, Brent M, Dassanayake, Wijaya
- Authors: Ncube, Keitometsi , Shackleton, Charlie M , Swallow, Brent M , Dassanayake, Wijaya
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180412 , vital:43385 , xlink:href="https://doi.org/10.1007/s12571-016-0624-4"
- Description: HIV/AIDS can affect household food consumption in many ways, including through reductions in availability and quality of labour, reductions in earned income, and increased expenditure on medications. In rural South Africa, these negative effects can be buffered by social safety net programs provided by government and collection of wild foods. Despite some acknowledgement of the potential safety net role of wild foods, however, their contribution relative to other food sources in the context of HIV/AIDS remains underexplored. Here we report empirical findings from two rural communities in the Eastern Cape province of South Africa. Qualitative and quantitative methods were used to characterise food sources, intake and calories from 68 HIV/AIDS afflicted households and 87 non-afflicted households every quarter over 12 months. Results show that diets were moderately well-balanced though limited in variety, with cereal items contributing 52 % to total calorie intake. The bulk of food consumed by households was purchased, with supplementation from own production, collected wild vegetables and collected wild fruits. Up to 20 % of respondents from both HIV/ AIDS afflicted and non-afflicted households had insufficient daily caloric intake. Multivariate analyses show that, all else equal, individuals living in households afflicted by HIV/AIDS consumed fewer calories, had less diverse diets, and were more dependent on wild foods than those living in non-afflicted households. Given the detrimental effects of HIV/AIDS on income and home production, wild foods represent a free and readily available food source for vulnerable households.
- Full Text:
- Authors: Ncube, Keitometsi , Shackleton, Charlie M , Swallow, Brent M , Dassanayake, Wijaya
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180412 , vital:43385 , xlink:href="https://doi.org/10.1007/s12571-016-0624-4"
- Description: HIV/AIDS can affect household food consumption in many ways, including through reductions in availability and quality of labour, reductions in earned income, and increased expenditure on medications. In rural South Africa, these negative effects can be buffered by social safety net programs provided by government and collection of wild foods. Despite some acknowledgement of the potential safety net role of wild foods, however, their contribution relative to other food sources in the context of HIV/AIDS remains underexplored. Here we report empirical findings from two rural communities in the Eastern Cape province of South Africa. Qualitative and quantitative methods were used to characterise food sources, intake and calories from 68 HIV/AIDS afflicted households and 87 non-afflicted households every quarter over 12 months. Results show that diets were moderately well-balanced though limited in variety, with cereal items contributing 52 % to total calorie intake. The bulk of food consumed by households was purchased, with supplementation from own production, collected wild vegetables and collected wild fruits. Up to 20 % of respondents from both HIV/ AIDS afflicted and non-afflicted households had insufficient daily caloric intake. Multivariate analyses show that, all else equal, individuals living in households afflicted by HIV/AIDS consumed fewer calories, had less diverse diets, and were more dependent on wild foods than those living in non-afflicted households. Given the detrimental effects of HIV/AIDS on income and home production, wild foods represent a free and readily available food source for vulnerable households.
- Full Text:
Improvement of nonlinear optical properties of phthalocyanine bearing diethyleneglycole chains
- Britton, Jonathan, Martynov, Alexander G, Oluwole, David O, Gorbunova, Yulia G, Tsivadze, Yulia G, Nyokong, Tebello
- Authors: Britton, Jonathan , Martynov, Alexander G , Oluwole, David O , Gorbunova, Yulia G , Tsivadze, Yulia G , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239812 , vital:50769 , xlink:href="https://doi.org/10.1142/S1088424616501042"
- Description: This paper reports the successful synthesis of the low symmetry phthalocyanines: metal-free 2,3-bis[2′-(2′′-hydroxyethoxy)ethoxy]-9,10,16,17,23,24-hexa-nn-butoxyphthalocyanine 1H22 and its zinc complex 1Zn along with their nonlinear optical (NLO) behavior in solution and in thin films. 1H NMR investigations evidenced of higher dissymmetry of electronic density in 1H22 in comparison with 1Zn. This dissymmetry is responsible for unusually higher values of Im[χ(3)χ(3)]/αα, βeffβeff, and γγ for 1H22in contrast to 1Zn, where the notable effect of heavy-metal enhancement of ISC was expected. Both compounds showed Im[χ(3)χ(3)]/αα values of the order of 10−11−11 in chloroform which are higher in comparison to the symmetrical octabutoxyphthalocyanine H2[(BuO)8Pc]. NLO properties of 1H22 were improved via its incorporation into polycarbonate polymeric matrix together with CdSe@CdS-TOPO quantum dots. In such composite the value of Im[χ(3)χ(3)]/αα was almost three times higher in comparison with 1H22 solution in chloroform. The obtained composites are expected to be perspective components of optical materials, capable of protection against strong light irradiation
- Full Text:
- Authors: Britton, Jonathan , Martynov, Alexander G , Oluwole, David O , Gorbunova, Yulia G , Tsivadze, Yulia G , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239812 , vital:50769 , xlink:href="https://doi.org/10.1142/S1088424616501042"
- Description: This paper reports the successful synthesis of the low symmetry phthalocyanines: metal-free 2,3-bis[2′-(2′′-hydroxyethoxy)ethoxy]-9,10,16,17,23,24-hexa-nn-butoxyphthalocyanine 1H22 and its zinc complex 1Zn along with their nonlinear optical (NLO) behavior in solution and in thin films. 1H NMR investigations evidenced of higher dissymmetry of electronic density in 1H22 in comparison with 1Zn. This dissymmetry is responsible for unusually higher values of Im[χ(3)χ(3)]/αα, βeffβeff, and γγ for 1H22in contrast to 1Zn, where the notable effect of heavy-metal enhancement of ISC was expected. Both compounds showed Im[χ(3)χ(3)]/αα values of the order of 10−11−11 in chloroform which are higher in comparison to the symmetrical octabutoxyphthalocyanine H2[(BuO)8Pc]. NLO properties of 1H22 were improved via its incorporation into polycarbonate polymeric matrix together with CdSe@CdS-TOPO quantum dots. In such composite the value of Im[χ(3)χ(3)]/αα was almost three times higher in comparison with 1H22 solution in chloroform. The obtained composites are expected to be perspective components of optical materials, capable of protection against strong light irradiation
- Full Text:
Improving Fidelity in Internet Simulation through Packet Injection
- Koorn, Craig, Irwin, Barry V W, Herbert, Alan
- Authors: Koorn, Craig , Irwin, Barry V W , Herbert, Alan
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427786 , vital:72462 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622877_Improving_Fidelity_in_Internet_Simulation_through_Packet_Injection/links/5b9a1a47458515310583fd8a/Improving-Fidelity-in-Internet-Simulation-through-Packet-Injection.pdf
- Description: This paper describes the of extension implemented to the NKM Internet simulation system, which allows for the improved of injection of packet traffic at arbitrary nodes, and the replay of previously recorded streams. The latter function allows for the relatively easy implementation of Internet Background Radiation (IBR) within the simulated portion of the Internet. This feature thereby enhances the degree of realism of the simulation, and allows for certain pre-determined traffic, such as scanning activity, to be injected and observed by client systems connected to the simulator.
- Full Text:
- Authors: Koorn, Craig , Irwin, Barry V W , Herbert, Alan
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427786 , vital:72462 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622877_Improving_Fidelity_in_Internet_Simulation_through_Packet_Injection/links/5b9a1a47458515310583fd8a/Improving-Fidelity-in-Internet-Simulation-through-Packet-Injection.pdf
- Description: This paper describes the of extension implemented to the NKM Internet simulation system, which allows for the improved of injection of packet traffic at arbitrary nodes, and the replay of previously recorded streams. The latter function allows for the relatively easy implementation of Internet Background Radiation (IBR) within the simulated portion of the Internet. This feature thereby enhances the degree of realism of the simulation, and allows for certain pre-determined traffic, such as scanning activity, to be injected and observed by client systems connected to the simulator.
- Full Text:
In search of the African voice in higher education: the language question
- Authors: Kaschula, Russell H
- Date: 2016
- Subjects: African languages -- Study and teaching (Higher) -- South Africa , Educational change -- South Africa , Education, Higher -- South Africa , Multiligualism , Language and languages -- Study and teaching
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59274 , vital:27539 , http://dx.doi.org/10.5842/49-0-658
- Description: This article seeks to understand what South African universities are doing by making use of language as a tool or as an enabling voice towards Africanisation and transformation with particular reference to Rhodes University, which serves as a case study. Although many universities now have language policies in place and are part of an enabling policy environment, when it comes to using language as part of transformation and asserting an African voice, there are still policy implementation challenges. It is argued in this article that implementation of policy, including university language policies, is now a key indicator for two levels of transformation; namely the more superficially visible or visual representation transformation, as well as deeper curriculum transformation through appropriate language usage. It is the latter form of transformation that largely eludes the contemporary South African university, whether these are historically black universities (HBUs) or historically white universities (HWUs). With the exception of a few best practices that are highlighted in this article, it is argued that transformation of the curriculum remains a long-term process, in the same way that language policy implementation is an ongoing process and requires commitment at all levels of university managerial and academic culture. The African voice in higher education remains an elusive one; though it is gaining ground, as evidenced by the recent removal of the Cecil John Rhodes Statue at the University of Cape Town. Furthermore, there is evidence of selected ongoing curriculum and pedagogic transformation, as presented in this article.
- Full Text:
- Authors: Kaschula, Russell H
- Date: 2016
- Subjects: African languages -- Study and teaching (Higher) -- South Africa , Educational change -- South Africa , Education, Higher -- South Africa , Multiligualism , Language and languages -- Study and teaching
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59274 , vital:27539 , http://dx.doi.org/10.5842/49-0-658
- Description: This article seeks to understand what South African universities are doing by making use of language as a tool or as an enabling voice towards Africanisation and transformation with particular reference to Rhodes University, which serves as a case study. Although many universities now have language policies in place and are part of an enabling policy environment, when it comes to using language as part of transformation and asserting an African voice, there are still policy implementation challenges. It is argued in this article that implementation of policy, including university language policies, is now a key indicator for two levels of transformation; namely the more superficially visible or visual representation transformation, as well as deeper curriculum transformation through appropriate language usage. It is the latter form of transformation that largely eludes the contemporary South African university, whether these are historically black universities (HBUs) or historically white universities (HWUs). With the exception of a few best practices that are highlighted in this article, it is argued that transformation of the curriculum remains a long-term process, in the same way that language policy implementation is an ongoing process and requires commitment at all levels of university managerial and academic culture. The African voice in higher education remains an elusive one; though it is gaining ground, as evidenced by the recent removal of the Cecil John Rhodes Statue at the University of Cape Town. Furthermore, there is evidence of selected ongoing curriculum and pedagogic transformation, as presented in this article.
- Full Text:
Incorporation of environmental issues in South Africa’s municipal Integrated Development Plans
- Ruwanza, Sheunesu, Shackleton, Charlie M
- Authors: Ruwanza, Sheunesu , Shackleton, Charlie M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180481 , vital:43393 , xlink:href="https://doi.org/10.1080/13504509.2015.1062161"
- Description: The transition to full democracy in South Africa in 1994 saw local government becoming the focal point for dealing with socio-economic development needs of communities. The Integrated Development Plan (IDP) has been used as the tool for guiding local development objectives, balanced against environmental demands within a sustainable development paradigm. Here we examine the extent to which this is being achieved through an analysis of IDPs from 35 different municipalities at three scales. We test the hypothesis that the metropolitan municipalities are better at mainstreaming environmental issues into their IDPs than local and district municipalities. Results indicate that mainstreaming environmental issues in IDPs is still low. The hypothesis that metropoles are better at mainstreaming environmental issues than district and local municipalities was not accepted since there were no significant differences between municipalities. There was low relative budget allocations and inclusion of vision and mission statements that mainstream environmental issues in all municipalities. For mainstreaming of environmental issues to be effective in IDPs, both proactive approaches and multi-faceted bottom-up and top-down approaches are suggested.
- Full Text:
- Authors: Ruwanza, Sheunesu , Shackleton, Charlie M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180481 , vital:43393 , xlink:href="https://doi.org/10.1080/13504509.2015.1062161"
- Description: The transition to full democracy in South Africa in 1994 saw local government becoming the focal point for dealing with socio-economic development needs of communities. The Integrated Development Plan (IDP) has been used as the tool for guiding local development objectives, balanced against environmental demands within a sustainable development paradigm. Here we examine the extent to which this is being achieved through an analysis of IDPs from 35 different municipalities at three scales. We test the hypothesis that the metropolitan municipalities are better at mainstreaming environmental issues into their IDPs than local and district municipalities. Results indicate that mainstreaming environmental issues in IDPs is still low. The hypothesis that metropoles are better at mainstreaming environmental issues than district and local municipalities was not accepted since there were no significant differences between municipalities. There was low relative budget allocations and inclusion of vision and mission statements that mainstream environmental issues in all municipalities. For mainstreaming of environmental issues to be effective in IDPs, both proactive approaches and multi-faceted bottom-up and top-down approaches are suggested.
- Full Text:
Infecting the city: site-situational performance and ambulatory hermeneutics
- Authors: Simbao, Ruth K
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146156 , vital:38500 , DOI: 10.1080/09528822.2016.1266776
- Description: This article proposes the term ‘site-situational’ art or performance as a meaningful shift beyond ‘site-specificity’ and as a way to develop forward-moving and relational understandings of place. While place falls prey to Western, modernist stereotypes of closed, territorial geographic systems, site-situational readings, radical forms of ‘recognition’ and ambulatory hermeneutics enable an understanding of place as a wandering signifier, a trickster figure, and an in-the-moment conversation between environments and living beings. Through an analysis of the 2009 Infecting the City performing arts festival in South Africa, the article links site-situational performance to situational understandings of identification in the context of migration and xenophobia. It connects the participatory creative resistance aspired to by the Situationists that transforms situations rather than just recognises them, to the potential mutuality that can be experienced when one recognises oneself in the face of a ‘foreigner’ as well as the potential culpability that accompanies pro-active recognition-on-the-run.
- Full Text:
- Authors: Simbao, Ruth K
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146156 , vital:38500 , DOI: 10.1080/09528822.2016.1266776
- Description: This article proposes the term ‘site-situational’ art or performance as a meaningful shift beyond ‘site-specificity’ and as a way to develop forward-moving and relational understandings of place. While place falls prey to Western, modernist stereotypes of closed, territorial geographic systems, site-situational readings, radical forms of ‘recognition’ and ambulatory hermeneutics enable an understanding of place as a wandering signifier, a trickster figure, and an in-the-moment conversation between environments and living beings. Through an analysis of the 2009 Infecting the City performing arts festival in South Africa, the article links site-situational performance to situational understandings of identification in the context of migration and xenophobia. It connects the participatory creative resistance aspired to by the Situationists that transforms situations rather than just recognises them, to the potential mutuality that can be experienced when one recognises oneself in the face of a ‘foreigner’ as well as the potential culpability that accompanies pro-active recognition-on-the-run.
- Full Text: