Conjugation of azide-functionalised CdSe/ZnS quantum dots with tetrakis (5-hexyn-oxy) Fe (II) phthalocyanine via click chemistry for electrocatalysis
- Nxele, Siphesihle R, Nyokong, Tebello
- Authors: Nxele, Siphesihle R , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188755 , vital:44782 , xlink:href="https://doi.org/10.1016/j.electacta.2016.01.234"
- Description: In this work, azide-funtionalised CdSe/ZnS QDs are conjugated with tetrakis(5-hexyn-oxy) Fe(II) phthalocyanine for the electrocatalytic detection of paraquat. The conjugate was fully characterised using various techniques to confirm the success of the reaction. They also showed good electrocatalytic ability towards the electroreduction of paraquat with limits of detection (LoD) of 5.9 × 10−9 μM which is a great improvement compared to other reported sensors for this analyte.
- Full Text:
- Authors: Nxele, Siphesihle R , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188755 , vital:44782 , xlink:href="https://doi.org/10.1016/j.electacta.2016.01.234"
- Description: In this work, azide-funtionalised CdSe/ZnS QDs are conjugated with tetrakis(5-hexyn-oxy) Fe(II) phthalocyanine for the electrocatalytic detection of paraquat. The conjugate was fully characterised using various techniques to confirm the success of the reaction. They also showed good electrocatalytic ability towards the electroreduction of paraquat with limits of detection (LoD) of 5.9 × 10−9 μM which is a great improvement compared to other reported sensors for this analyte.
- Full Text:
Constructing a local approach to journalism education: a study of Zambian educators’ conceptualisation of the ideal journalism curriculum
- Authors: Milupi, Mulako
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3552 , http://hdl.handle.net/10962/d1021228
- Description: This research is an investigation of Zambian journalism educators’ conception of the knowledge, competencies and values that should inform their teaching practice. The study establishes how such educators conceptualise of the purpose of journalism education within the Zambian context. As part of this examination, it identifies characteristics of this context that educators regard to be of relevance to their conceptualisation of such purpose. It then identifies what they understand as the implications for the design of the ideal journalism education curriculum. The study assesses the relevance of these perspectives to the teaching of journalism in Zambia, as an example of an African country with a ‘developing’ economy. The study draws for its theoretical framework on journalism studies generally and scholarship about journalism education more specifically. It is argued that a review of the global history of journalism education points to the existence of three main traditions of teaching that have developed internationally. The first of these traditions is described as being dedicated to the project of ‘professionalisation’; the second to the production of ‘critical practitioners’, and the third to the project of ‘social development’. These traditions are based on different understandings with regard to the principles on which journalism education programmes should be based and the kind of knowledge that they should draw on. It is noted that this body of literature does not include extensive research of the way in which particular groups of African journalism educators respond to these traditions. In order to contribute to such research, the empirical component of this study sets out to explore Zambian journalism educators’ conceptualisation of journalism education within their own social context. It does so by means of an exploration of journalism educators based, respectively, at the Evelyn Hone College of Applied Arts (EHC) and the University of Zambia (UNZA)’s Mass Communication Department. The foremost conclusion of the research is that both the professionalising and developmental tradition can be observed to influence the participants’ discussion.
- Full Text:
- Authors: Milupi, Mulako
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3552 , http://hdl.handle.net/10962/d1021228
- Description: This research is an investigation of Zambian journalism educators’ conception of the knowledge, competencies and values that should inform their teaching practice. The study establishes how such educators conceptualise of the purpose of journalism education within the Zambian context. As part of this examination, it identifies characteristics of this context that educators regard to be of relevance to their conceptualisation of such purpose. It then identifies what they understand as the implications for the design of the ideal journalism education curriculum. The study assesses the relevance of these perspectives to the teaching of journalism in Zambia, as an example of an African country with a ‘developing’ economy. The study draws for its theoretical framework on journalism studies generally and scholarship about journalism education more specifically. It is argued that a review of the global history of journalism education points to the existence of three main traditions of teaching that have developed internationally. The first of these traditions is described as being dedicated to the project of ‘professionalisation’; the second to the production of ‘critical practitioners’, and the third to the project of ‘social development’. These traditions are based on different understandings with regard to the principles on which journalism education programmes should be based and the kind of knowledge that they should draw on. It is noted that this body of literature does not include extensive research of the way in which particular groups of African journalism educators respond to these traditions. In order to contribute to such research, the empirical component of this study sets out to explore Zambian journalism educators’ conceptualisation of journalism education within their own social context. It does so by means of an exploration of journalism educators based, respectively, at the Evelyn Hone College of Applied Arts (EHC) and the University of Zambia (UNZA)’s Mass Communication Department. The foremost conclusion of the research is that both the professionalising and developmental tradition can be observed to influence the participants’ discussion.
- Full Text:
Constructions of roles in studio teaching and learning
- Authors: Belluigi, Dina Z
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59792 , vital:27651 , https://doi.org/10.1111/jade.12042
- Description: Various constructions of supervisors and students emerge from education literature on art, design and architecture studio pedagogy. Constructions of the supervisor within the studio and during assessment are considered, with a discussion of the threads which underpin them. This is followed by a discussion of some of the current dominant constructions of the student, and possible effects of these roles and relationships on their engagement with learning. As many of these constructions may be inherited or unconscious, a concern for the agency of those involved to rupture, subvert, rescript or resist such constructions motivates this research, while acknowledging that this may be limited by structural and cultural contexts.
- Full Text: false
- Authors: Belluigi, Dina Z
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59792 , vital:27651 , https://doi.org/10.1111/jade.12042
- Description: Various constructions of supervisors and students emerge from education literature on art, design and architecture studio pedagogy. Constructions of the supervisor within the studio and during assessment are considered, with a discussion of the threads which underpin them. This is followed by a discussion of some of the current dominant constructions of the student, and possible effects of these roles and relationships on their engagement with learning. As many of these constructions may be inherited or unconscious, a concern for the agency of those involved to rupture, subvert, rescript or resist such constructions motivates this research, while acknowledging that this may be limited by structural and cultural contexts.
- Full Text: false
Contesting masculinities: a study of selected texts of resistance to conscription into the South African Defence Force (SADF) in the 1980s
- Authors: Mason, Paul
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2332 , http://hdl.handle.net/10962/d1020842
- Description: The theoretical framework for this thesis and analysis of primary texts revolves around the problem of conscription into the South African Defence Force (SADF) in the 1980s. The ideology of masculinity that underpinned and sustained the practice of conscription is referred to throughout as the hegemonic version. This term is interchangeable with others, namely masculinism and ‗the real man.‘ The aim is to interpret the selected texts for strains of resistance to the practice of conscription and its assumptions as to what to what constitutes the natural or real man. In the Introduction to this thesis I begin by explaining the personal dimension of my role as researcher, after which I motivate my research project and explain its theoretical and methodological orientation, focusing on the concepts that play a significant role in analysis of the primary texts. The Introduction concludes with an outline of the content of Chapters 1–5. Chapter 1 begins with a brief discussion, on the general level, of the practice of conscription and resistance to it, and proceeds to a concern with conscription in 1980s South Africa. Attention is paid to prevailing attitudes towards gender and sexuality within both the SADF and the End Conscription Campaign (ECC). Discussion of gender and sexuality as constructs of identity proceeds to a focus on the conceptual tools for textual analysis provided by theories of masculinity. The final section of this chapter pays attention to specific post-structuralist notions of identity that serve analysis of the primary texts, that is, the notions of the subject, agency and the author. Having engaged mainly with secondary texts in Chapter 1, Chapter 2 presents the first sustained critical engagement with primary texts in which resistance was expressed against the institution of conscription and the hegemonic version of masculinity that underpinned it. These expressions of resistance occurred within a rock music counter-culture of the period, known as the Voëlvry movement. Attention is given to overlaps or links between this counter-culture and that of America in the 1960s, as well echoes between the Vietnam and Border Wars. Analysis of these links is applied to a memoir selected for its appropriateness. Threaded through the chapter is a concern with expressions of masculine identity within the Voëlvry counter-culture, the SADF and the ECC. Chapter 3 focuses on three novels and one collection of short stories, each narrated in the first person and written by gay authors who performed their National Service. Attention is paid to the protagonists‘ perceptions of themselves, their troubled relationships with their fathers, and the struggle to come out within a context that prohibited them from doing so. Chapter 4 concerns three wartime memoirs and two written by men who refused to perform their National Service. Underlying concerns in this chapter are the question of fact versus fiction in the genre of the memoir, authors‘ perceptions of and relationships with women, and expressions of vulnerability. Chapter 5 concentrates on the interviews that comprise the Appendix. The chapter establishes its theoretical ground by focusing on principles of narrative structure and the relation of personal to narrative identity. The chapter pays attention to the displays of power and the vulnerabilities of both veteran soldiers and resisters. Theory deployed in analysis of the primary texts serves the principal concerns articulated in the title to the thesis.
- Full Text:
- Authors: Mason, Paul
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2332 , http://hdl.handle.net/10962/d1020842
- Description: The theoretical framework for this thesis and analysis of primary texts revolves around the problem of conscription into the South African Defence Force (SADF) in the 1980s. The ideology of masculinity that underpinned and sustained the practice of conscription is referred to throughout as the hegemonic version. This term is interchangeable with others, namely masculinism and ‗the real man.‘ The aim is to interpret the selected texts for strains of resistance to the practice of conscription and its assumptions as to what to what constitutes the natural or real man. In the Introduction to this thesis I begin by explaining the personal dimension of my role as researcher, after which I motivate my research project and explain its theoretical and methodological orientation, focusing on the concepts that play a significant role in analysis of the primary texts. The Introduction concludes with an outline of the content of Chapters 1–5. Chapter 1 begins with a brief discussion, on the general level, of the practice of conscription and resistance to it, and proceeds to a concern with conscription in 1980s South Africa. Attention is paid to prevailing attitudes towards gender and sexuality within both the SADF and the End Conscription Campaign (ECC). Discussion of gender and sexuality as constructs of identity proceeds to a focus on the conceptual tools for textual analysis provided by theories of masculinity. The final section of this chapter pays attention to specific post-structuralist notions of identity that serve analysis of the primary texts, that is, the notions of the subject, agency and the author. Having engaged mainly with secondary texts in Chapter 1, Chapter 2 presents the first sustained critical engagement with primary texts in which resistance was expressed against the institution of conscription and the hegemonic version of masculinity that underpinned it. These expressions of resistance occurred within a rock music counter-culture of the period, known as the Voëlvry movement. Attention is given to overlaps or links between this counter-culture and that of America in the 1960s, as well echoes between the Vietnam and Border Wars. Analysis of these links is applied to a memoir selected for its appropriateness. Threaded through the chapter is a concern with expressions of masculine identity within the Voëlvry counter-culture, the SADF and the ECC. Chapter 3 focuses on three novels and one collection of short stories, each narrated in the first person and written by gay authors who performed their National Service. Attention is paid to the protagonists‘ perceptions of themselves, their troubled relationships with their fathers, and the struggle to come out within a context that prohibited them from doing so. Chapter 4 concerns three wartime memoirs and two written by men who refused to perform their National Service. Underlying concerns in this chapter are the question of fact versus fiction in the genre of the memoir, authors‘ perceptions of and relationships with women, and expressions of vulnerability. Chapter 5 concentrates on the interviews that comprise the Appendix. The chapter establishes its theoretical ground by focusing on principles of narrative structure and the relation of personal to narrative identity. The chapter pays attention to the displays of power and the vulnerabilities of both veteran soldiers and resisters. Theory deployed in analysis of the primary texts serves the principal concerns articulated in the title to the thesis.
- Full Text:
Controls on the distribution of manganese in banded iron-formations (BIF) of the palaeoproterozoic transvaal supergroup, South Africa
- Authors: Fryer, Lindi
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2926 , vital:20343
- Description: The 2.65 to 2.05 Ga Transvaal Supergroup comprises one of the best-preserved and largely continuous successions in the world of Banded Iron-Formation (BIF), a chemical sedimentary rock composed of fine (mm to cm scale) interbanded iron-rich and iron-poor bands, developed atop the Archaean Kaapvaal Craton of southern Africa. The Transvaal BIF sequence contains at its upper stratigraphic part, an intriguing interlayered BIF-Mn association, namely the Hotazel Formation in the Kalahari Manganese Field, which constitutes the largest land-based manganese deposit on record. The genesis of the Hotazel deposits, and their exact significance in terms of atmosphere-hydrosphere-biosphere evolution, remain as elusive as they are challenging. In this thesis, an attempt is made to illuminate the origin and diagenesis of the Hotazel Formation and its post-depositional hydrothermal modification, through a highresolution geochemical study of the narrowest of the three BIF-Mn sedimentary cycles present in the Hotazel stratigraphy. This approach is coupled with a preliminary geochemical study of the distribution of Mn in older BIF of the Transvaal Supergroup as well (Kuruman and Griquatown Formations), so as to test recent models that causally link all BIFs in the Transvaal Supergroup under a common and evolving palaeo-environment of deposition. The results indicate that the cyclic deposition of the Hotazel BIF and enveloped Mn-rich sediments would have taken place in a stratified basin with a well-developed chemocline in terms of the vertical distributions of Mn and Fe, much like recent anoxic stratified basins such as the Orca Basin in the Gulf of Mexico. The increased Mn abundances as Mn-bearing ferrous carbonates in the upper part of the Griquatown BIF predating the Hotazel strata, also seems to lend support to the notion that the two BIFs are temporally interlinked as part of a broader sedimentary continuum. Finally, the largely conservative behaviour of Mn and associated elements during hydrothermal alteration of the Hotazel rocks is re-assessed, and renewed emphasis is placed on the possibility that brine metasomatism may have been a key factor in Mn redistribution and residual enrichment.
- Full Text:
- Authors: Fryer, Lindi
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2926 , vital:20343
- Description: The 2.65 to 2.05 Ga Transvaal Supergroup comprises one of the best-preserved and largely continuous successions in the world of Banded Iron-Formation (BIF), a chemical sedimentary rock composed of fine (mm to cm scale) interbanded iron-rich and iron-poor bands, developed atop the Archaean Kaapvaal Craton of southern Africa. The Transvaal BIF sequence contains at its upper stratigraphic part, an intriguing interlayered BIF-Mn association, namely the Hotazel Formation in the Kalahari Manganese Field, which constitutes the largest land-based manganese deposit on record. The genesis of the Hotazel deposits, and their exact significance in terms of atmosphere-hydrosphere-biosphere evolution, remain as elusive as they are challenging. In this thesis, an attempt is made to illuminate the origin and diagenesis of the Hotazel Formation and its post-depositional hydrothermal modification, through a highresolution geochemical study of the narrowest of the three BIF-Mn sedimentary cycles present in the Hotazel stratigraphy. This approach is coupled with a preliminary geochemical study of the distribution of Mn in older BIF of the Transvaal Supergroup as well (Kuruman and Griquatown Formations), so as to test recent models that causally link all BIFs in the Transvaal Supergroup under a common and evolving palaeo-environment of deposition. The results indicate that the cyclic deposition of the Hotazel BIF and enveloped Mn-rich sediments would have taken place in a stratified basin with a well-developed chemocline in terms of the vertical distributions of Mn and Fe, much like recent anoxic stratified basins such as the Orca Basin in the Gulf of Mexico. The increased Mn abundances as Mn-bearing ferrous carbonates in the upper part of the Griquatown BIF predating the Hotazel strata, also seems to lend support to the notion that the two BIFs are temporally interlinked as part of a broader sedimentary continuum. Finally, the largely conservative behaviour of Mn and associated elements during hydrothermal alteration of the Hotazel rocks is re-assessed, and renewed emphasis is placed on the possibility that brine metasomatism may have been a key factor in Mn redistribution and residual enrichment.
- Full Text:
Cosmological structure formation using spectral methods
- Authors: Funcke, Michelle
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2969 , vital:20348
- Description: Numerical simulations are becoming an increasingly important tool for understanding the growth and development of structure in the universe. Common practice is to discretize the space-time using physical variables. The discreteness is embodied by considering the dynamical variables as fields on a fixed spatial and time resolution, or by constructing the matter fields by a large number of particles which interact gravitationally (N-body methods). Recognizing that the physical quantities of interest are related to the spectrum of perturbations, we propose an alternate discretization in the frequency domain, using standard spectral methods. This approach is further aided by periodic boundary conditions which allows a straightforward decomposition of variables in a Fourier basis. Fixed resources require a high-frequency cut-off which lead to aliasing effects in non-linear equations, such as the ones considered here. This thesis describes the implementation of a 3D cosmological model based on Newtonian hydrodynamic equations in an expanding background. Initial data is constructed as a spectrum of perturbations, and evolved in the frequency domain using a pseudo-spectral evolution scheme and an explicit Runge-Kutta time integrator. The code is found to converge for both linear and non-linear evolutions, and the convergence rate is determined. The correct growth rates expected from analytical calculations are recovered in the linear case. In the non-linear model, we observe close correspondence with linear growth and are able to monitor the growth on features associated with the non-linearity. High-frequency aliasing effects were evident in the non-linear evolutions, leading to a study of two potential resolutions to this problem: a boxcar filter which adheres to“Orszag’s two thirds rule” and an exponential window function, the exponential filter suggested by Hou and Li [1], and a shifted version of the exponential filter suggested, which has the potential to alleviate high frequency- ripples resulting from the Gibbs’ phenomenon. We found that the filters were somewhat successful at reducing aliasing effects but that the Gibbs’ phenomenon could not be entirely removed by the choice of filters.
- Full Text:
- Authors: Funcke, Michelle
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2969 , vital:20348
- Description: Numerical simulations are becoming an increasingly important tool for understanding the growth and development of structure in the universe. Common practice is to discretize the space-time using physical variables. The discreteness is embodied by considering the dynamical variables as fields on a fixed spatial and time resolution, or by constructing the matter fields by a large number of particles which interact gravitationally (N-body methods). Recognizing that the physical quantities of interest are related to the spectrum of perturbations, we propose an alternate discretization in the frequency domain, using standard spectral methods. This approach is further aided by periodic boundary conditions which allows a straightforward decomposition of variables in a Fourier basis. Fixed resources require a high-frequency cut-off which lead to aliasing effects in non-linear equations, such as the ones considered here. This thesis describes the implementation of a 3D cosmological model based on Newtonian hydrodynamic equations in an expanding background. Initial data is constructed as a spectrum of perturbations, and evolved in the frequency domain using a pseudo-spectral evolution scheme and an explicit Runge-Kutta time integrator. The code is found to converge for both linear and non-linear evolutions, and the convergence rate is determined. The correct growth rates expected from analytical calculations are recovered in the linear case. In the non-linear model, we observe close correspondence with linear growth and are able to monitor the growth on features associated with the non-linearity. High-frequency aliasing effects were evident in the non-linear evolutions, leading to a study of two potential resolutions to this problem: a boxcar filter which adheres to“Orszag’s two thirds rule” and an exponential window function, the exponential filter suggested by Hou and Li [1], and a shifted version of the exponential filter suggested, which has the potential to alleviate high frequency- ripples resulting from the Gibbs’ phenomenon. We found that the filters were somewhat successful at reducing aliasing effects but that the Gibbs’ phenomenon could not be entirely removed by the choice of filters.
- Full Text:
Creating evidence-based guidelines for healthy eating educational campaigns aimed at low-income South Africans: a case study of Grahamstown
- Authors: Booth, Christopher
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3336 , vital:20485
- Description: Through a literature review and qualitative research, this study explores what a media-centric nutritional intervention needs to include in order to be effective amongst those whose health is most impacted by poor nutrition – poorer and mostly black South Africans. The study sketches the current nutritional landscape of South Africa, and draws on both Behaviour Change Communication and Media Effect theories to hypothesise how a campaign might be devised to change popular understandings of the relationship between health and nutrition, and inspire some change in food consumption behaviours and choices. The study explores the key factors that drive nutritional behaviours (including the environmental constraint of cost, the peer pressure and socialisation of food, and the desire for knowledge and change) and explores how media-based interventions could be more effective. To do this, this study creates three layers of an idealised and hypothetical “Super 7” fruit and vegetable consumption promotion campaign. From this data, and the insights developed, new guidelines for possible future nutritional education campaigns are suggested and developed.
- Full Text:
- Authors: Booth, Christopher
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3336 , vital:20485
- Description: Through a literature review and qualitative research, this study explores what a media-centric nutritional intervention needs to include in order to be effective amongst those whose health is most impacted by poor nutrition – poorer and mostly black South Africans. The study sketches the current nutritional landscape of South Africa, and draws on both Behaviour Change Communication and Media Effect theories to hypothesise how a campaign might be devised to change popular understandings of the relationship between health and nutrition, and inspire some change in food consumption behaviours and choices. The study explores the key factors that drive nutritional behaviours (including the environmental constraint of cost, the peer pressure and socialisation of food, and the desire for knowledge and change) and explores how media-based interventions could be more effective. To do this, this study creates three layers of an idealised and hypothetical “Super 7” fruit and vegetable consumption promotion campaign. From this data, and the insights developed, new guidelines for possible future nutritional education campaigns are suggested and developed.
- Full Text:
Crime travel: a survey of representations of transnational crime in South African crime fiction
- Authors: Naidu, Samantha
- Date: 2016
- Language: English
- Type: Article
- Identifier: vital:26347 , http://hdl.handle.net/10962/53900 , http://jcpcsonline.com/ , https://orcid.org/0000-0001-9456-8657
- Description: The literatures, the histories, the politics, and the arts whose focus, locales, or subjects involve Britain and other European countries and their former colonies, the now decolonized, independent nations in the Americas, Africa, Asia, and the Caribbean, and also Australia, Canada, Ireland, and New Zealand.
- Full Text: false
- Authors: Naidu, Samantha
- Date: 2016
- Language: English
- Type: Article
- Identifier: vital:26347 , http://hdl.handle.net/10962/53900 , http://jcpcsonline.com/ , https://orcid.org/0000-0001-9456-8657
- Description: The literatures, the histories, the politics, and the arts whose focus, locales, or subjects involve Britain and other European countries and their former colonies, the now decolonized, independent nations in the Americas, Africa, Asia, and the Caribbean, and also Australia, Canada, Ireland, and New Zealand.
- Full Text: false
Curriculum in the context of transformation: reframing traditional understandings and practices
- Authors: Voster, Jo-Anne
- Date: 2016
- Language: English
- Type: Book , text
- Identifier: http://hdl.handle.net/10962/59557 , vital:27626
- Description: Curriculum is central to the pedagogic project of the university, and like all aspects of education, it is underpinned by values, beliefs and ideologies. Curriculum choices are made based on what disciplines and professions value and what academic departments and / or individual academics find interesting and believe to be useful for students to learn and know. Decisions about how to teach and assess curriculum knowledge is very often made on the basis of lecturers’ preferences and beliefs about good teaching and learning. At the current conjuncture, academics in South African higher education are also called upon to take into account a number of transformation imperatives when making curriculum choices. The case studies in this collection present examples of how some lecturers at Rhodes University are thinking about curriculum in the context of cur - rent educational concerns and show some of the ways in which they attempt to ensure that greater epistemological access becomes a reality for more students.
- Full Text:
- Authors: Voster, Jo-Anne
- Date: 2016
- Language: English
- Type: Book , text
- Identifier: http://hdl.handle.net/10962/59557 , vital:27626
- Description: Curriculum is central to the pedagogic project of the university, and like all aspects of education, it is underpinned by values, beliefs and ideologies. Curriculum choices are made based on what disciplines and professions value and what academic departments and / or individual academics find interesting and believe to be useful for students to learn and know. Decisions about how to teach and assess curriculum knowledge is very often made on the basis of lecturers’ preferences and beliefs about good teaching and learning. At the current conjuncture, academics in South African higher education are also called upon to take into account a number of transformation imperatives when making curriculum choices. The case studies in this collection present examples of how some lecturers at Rhodes University are thinking about curriculum in the context of cur - rent educational concerns and show some of the ways in which they attempt to ensure that greater epistemological access becomes a reality for more students.
- Full Text:
Cyclodextrin grafted calcium carbonate vaterite particles: efficient system for tailored release of hydrophobic anticancer or hormone drugs
- Lakkakula, Jaya R, Kurapati, Rajendra, Tynga, Ivan, Krause, Rui W M, Abrahamse, Heidi, Raichur, Ashok M
- Authors: Lakkakula, Jaya R , Kurapati, Rajendra , Tynga, Ivan , Krause, Rui W M , Abrahamse, Heidi , Raichur, Ashok M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125435 , vital:35783 , https://doi.org/10.1039/C6RA12951J
- Description: Porous CaCO3 microparticles have been used earlier for sustained drug release of hydrophilic drugs but have certain drawbacks for use with hydrophobic drugs. Hence, to overcome these drawbacks, a novel composite of CaCO3 along with cyclodextrin (CD–CaCO3) for the delivery of hydrophobic drugs was developed. Cyclodextrins (CDs), when incorporated within CaCO3, increased the porosity and surface area of microparticles thereby enhancing the encapsulation efficiency of hydrophobic drugs (5-Fluorouracil or Na-L-thyroxine) by forming inclusion complexes with cyclodextrin. Thermogravimetric and FTIR studies confirmed the interaction between the cyclodextrin and CaCO3 microparticles. Raman spectra confirmed the peak of vaterite crystals before and after loading of hydrophobic drugs within the composite. In vitro release studies when performed at pH 4.8 (5-Fu) and pH 1.2 (Na-L-thy) showed release at low pH as CaCO3 is soluble at acidic pH unlike slower release at basic pH. Release kinetics followed a Higuchi kinetic model at pH 4.8 (5-Fu) and pH 1.2 (Na-L-thy) respectively.
- Full Text:
- Authors: Lakkakula, Jaya R , Kurapati, Rajendra , Tynga, Ivan , Krause, Rui W M , Abrahamse, Heidi , Raichur, Ashok M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125435 , vital:35783 , https://doi.org/10.1039/C6RA12951J
- Description: Porous CaCO3 microparticles have been used earlier for sustained drug release of hydrophilic drugs but have certain drawbacks for use with hydrophobic drugs. Hence, to overcome these drawbacks, a novel composite of CaCO3 along with cyclodextrin (CD–CaCO3) for the delivery of hydrophobic drugs was developed. Cyclodextrins (CDs), when incorporated within CaCO3, increased the porosity and surface area of microparticles thereby enhancing the encapsulation efficiency of hydrophobic drugs (5-Fluorouracil or Na-L-thyroxine) by forming inclusion complexes with cyclodextrin. Thermogravimetric and FTIR studies confirmed the interaction between the cyclodextrin and CaCO3 microparticles. Raman spectra confirmed the peak of vaterite crystals before and after loading of hydrophobic drugs within the composite. In vitro release studies when performed at pH 4.8 (5-Fu) and pH 1.2 (Na-L-thy) showed release at low pH as CaCO3 is soluble at acidic pH unlike slower release at basic pH. Release kinetics followed a Higuchi kinetic model at pH 4.8 (5-Fu) and pH 1.2 (Na-L-thy) respectively.
- Full Text:
Cytotoxic activity of marine sponge extracts from the sub-Antarctic Islands and the Southern Ocean
- Olsen, Elisabeth, De Cerf, Christopher, Dziwornu, Godwin A, Puccinelli, Eleonora, Parker-Nance, Shirley, Ansorge, Isabelle J, Samaai, Toufiek, Dingle, Laura M K, Edkins, Adrienne L, Sunassee, Suthananda N
- Authors: Olsen, Elisabeth , De Cerf, Christopher , Dziwornu, Godwin A , Puccinelli, Eleonora , Parker-Nance, Shirley , Ansorge, Isabelle J , Samaai, Toufiek , Dingle, Laura M K , Edkins, Adrienne L , Sunassee, Suthananda N
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66300 , vital:28931 , https://doi.org/10.17159/sajs.2016/20160202
- Description: publisher version , Over the past 50 years, marine invertebrates, especially sponges, have proven to be a valuable source of new and/or bioactive natural products that have the potential to be further developed as lead compounds for pharmaceutical applications. Although marine benthic invertebrate communities occurring off the coast of South Africa have been explored for their biomedicinal potential, the natural product investigation of marine sponges from the sub-Antarctic Islands in the Southern Ocean for the presence of bioactive secondary metabolites has been relatively unexplored thus far. We report here the results for the biological screening of both aqueous and organic extracts prepared from nine specimens of eight species of marine sponges, collected from around Marion Island and the Prince Edward Islands in the Southern Ocean, for their cytotoxic activity against three cancer cell lines. The results obtained through this multidisciplinary collaborative research effort by exclusively South African institutions has provided an exciting opportunity to discover cytotoxic compounds from sub-Antarctic sponges, whilst contributing to our understanding of the biodiversity and geographic distributions of these cold-water invertebrates. Therefore, we acknowledge here the various contributions of the diverse scientific disciplines that played a pivotal role in providing the necessary platform for the future natural products chemistry investigation of these marine sponges from the sub- Antarctic Islands and the Southern Ocean. Significance: This study will contribute to understanding the biodiversity and geographic distributions of sponges in the Southern Ocean. This multidisciplinary project has enabled the investigation of marine sponges for the presence of cytotoxic compounds. Further investigation will lead to the isolation and identification of cytotoxic compounds present in the active sponge extracts. , University of Cape Town; South African Medical Research Council; National Research Foundation (South Africa); CANSA; Rhodes University; Department of Science and Technology; Department of Environmental Affairs; SANAP
- Full Text:
- Authors: Olsen, Elisabeth , De Cerf, Christopher , Dziwornu, Godwin A , Puccinelli, Eleonora , Parker-Nance, Shirley , Ansorge, Isabelle J , Samaai, Toufiek , Dingle, Laura M K , Edkins, Adrienne L , Sunassee, Suthananda N
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66300 , vital:28931 , https://doi.org/10.17159/sajs.2016/20160202
- Description: publisher version , Over the past 50 years, marine invertebrates, especially sponges, have proven to be a valuable source of new and/or bioactive natural products that have the potential to be further developed as lead compounds for pharmaceutical applications. Although marine benthic invertebrate communities occurring off the coast of South Africa have been explored for their biomedicinal potential, the natural product investigation of marine sponges from the sub-Antarctic Islands in the Southern Ocean for the presence of bioactive secondary metabolites has been relatively unexplored thus far. We report here the results for the biological screening of both aqueous and organic extracts prepared from nine specimens of eight species of marine sponges, collected from around Marion Island and the Prince Edward Islands in the Southern Ocean, for their cytotoxic activity against three cancer cell lines. The results obtained through this multidisciplinary collaborative research effort by exclusively South African institutions has provided an exciting opportunity to discover cytotoxic compounds from sub-Antarctic sponges, whilst contributing to our understanding of the biodiversity and geographic distributions of these cold-water invertebrates. Therefore, we acknowledge here the various contributions of the diverse scientific disciplines that played a pivotal role in providing the necessary platform for the future natural products chemistry investigation of these marine sponges from the sub- Antarctic Islands and the Southern Ocean. Significance: This study will contribute to understanding the biodiversity and geographic distributions of sponges in the Southern Ocean. This multidisciplinary project has enabled the investigation of marine sponges for the presence of cytotoxic compounds. Further investigation will lead to the isolation and identification of cytotoxic compounds present in the active sponge extracts. , University of Cape Town; South African Medical Research Council; National Research Foundation (South Africa); CANSA; Rhodes University; Department of Science and Technology; Department of Environmental Affairs; SANAP
- Full Text:
Decolonising education: visual arts, cohesion, transformation
- Authors: Nsele, Zamansele
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146456 , vital:38527 , https://savah.org.za/2016/01/18/call-for-papers-savah-conference-2016/#more-174
- Description: Rethinking Art History and Visual Culture in a Contemporary Context. The Rhodes Must Fall” and “Fees Must Fall” campaigns which arose in South Africa in the course of 2015, while focused on transformative agendas in a broad sense, also emphasised how various inheritances from the West have played a fundamental role in shaping universities – not only in terms of their curricula but also their institutional cultures more generally. Occurring in a context where the humanities are under threat and where neoliberal forces may upset what we understand as fundamental to the academic project, these recent calls for critical engagement with institutional histories and practices suggest that reconsideration of disciplinary knowledges and understandings have become increasingly urgent.
- Full Text:
- Authors: Nsele, Zamansele
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146456 , vital:38527 , https://savah.org.za/2016/01/18/call-for-papers-savah-conference-2016/#more-174
- Description: Rethinking Art History and Visual Culture in a Contemporary Context. The Rhodes Must Fall” and “Fees Must Fall” campaigns which arose in South Africa in the course of 2015, while focused on transformative agendas in a broad sense, also emphasised how various inheritances from the West have played a fundamental role in shaping universities – not only in terms of their curricula but also their institutional cultures more generally. Occurring in a context where the humanities are under threat and where neoliberal forces may upset what we understand as fundamental to the academic project, these recent calls for critical engagement with institutional histories and practices suggest that reconsideration of disciplinary knowledges and understandings have become increasingly urgent.
- Full Text:
Depth and habitat determine assemblage structure of South Africa’s warm-temperate reef fish
- Heyns-Veale, Elodie R, Bernard, Anthony T F, Richoux, Nicole B, Parker, Daniel M, Langlois, T J, Harvey, E S, Götz, Albrecht
- Authors: Heyns-Veale, Elodie R , Bernard, Anthony T F , Richoux, Nicole B , Parker, Daniel M , Langlois, T J , Harvey, E S , Götz, Albrecht
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/456035 , vital:75477 , xlink:href="https://doi.org/10.1007/s00227-016-2933-8"
- Description: Depth and habitat are important predictors of fish assemblage structure, yet current no-take marine protected area (MPA) networks are generally limited to providing refuge for fish species that inhabit shallow waters and may exclude deep habitats essential to exploited populations. To ensure MPA efficacy at the design, uptake and management levels, baseline data on fish populations associated with deep nearshore reefs are needed. This study employed baited remote underwater stereo-video systems to investigate fish habitat associations at shallow (11–25 m) and deep (45–75 m) reef sites in the Tsitsikamma National Park MPA, South Africa. The compositions of fish assemblages at shallow and deep reef sites were significantly different. Specifically, rare species, juveniles and low trophic level species dominated the shallow reef, while deep reef assemblages were characterised by large, sexually mature and predatory fish. The body size of abundant species was also correlated with depth, with larger individuals being more abundant on deeper reefs. Habitat types were identified according to a habitat classification system established in a previous study, which resulted in four broad depth separated habitat types (defined by macrobenthos and environmental variables). Canonical analysis of principle coordinates (CAP) indicated that habitat type was a good categorical predictor of the observed fish assemblages. The CAP analysis determined that 86 % of the samples were correctly assigned to the habitat type from which they were collected, indicating that specific fish assemblages were associated with distinct habitat types. This study highlights the importance of protecting both shallow and deep reefs, not only to ensure the conservation of particular fish assemblages, but also to provide protection for all stages of the life cycle of fish species.
- Full Text:
- Authors: Heyns-Veale, Elodie R , Bernard, Anthony T F , Richoux, Nicole B , Parker, Daniel M , Langlois, T J , Harvey, E S , Götz, Albrecht
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/456035 , vital:75477 , xlink:href="https://doi.org/10.1007/s00227-016-2933-8"
- Description: Depth and habitat are important predictors of fish assemblage structure, yet current no-take marine protected area (MPA) networks are generally limited to providing refuge for fish species that inhabit shallow waters and may exclude deep habitats essential to exploited populations. To ensure MPA efficacy at the design, uptake and management levels, baseline data on fish populations associated with deep nearshore reefs are needed. This study employed baited remote underwater stereo-video systems to investigate fish habitat associations at shallow (11–25 m) and deep (45–75 m) reef sites in the Tsitsikamma National Park MPA, South Africa. The compositions of fish assemblages at shallow and deep reef sites were significantly different. Specifically, rare species, juveniles and low trophic level species dominated the shallow reef, while deep reef assemblages were characterised by large, sexually mature and predatory fish. The body size of abundant species was also correlated with depth, with larger individuals being more abundant on deeper reefs. Habitat types were identified according to a habitat classification system established in a previous study, which resulted in four broad depth separated habitat types (defined by macrobenthos and environmental variables). Canonical analysis of principle coordinates (CAP) indicated that habitat type was a good categorical predictor of the observed fish assemblages. The CAP analysis determined that 86 % of the samples were correctly assigned to the habitat type from which they were collected, indicating that specific fish assemblages were associated with distinct habitat types. This study highlights the importance of protecting both shallow and deep reefs, not only to ensure the conservation of particular fish assemblages, but also to provide protection for all stages of the life cycle of fish species.
- Full Text:
Depth-related distribution patterns of subtidal macrobenthos in a well-established marine protected area
- Heyns, E R, Bernard, Anthony T F, Richoux, Nicole B, Götz, A
- Authors: Heyns, E R , Bernard, Anthony T F , Richoux, Nicole B , Götz, A
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457230 , vital:75618 , xlink:href="https://doi.org/10.1007/s00227-016-2816-z"
- Description: Effective marine resource management requires knowledge of the distribution of critical habitats that support resource populations and the processes that maintain them. Reefs that host diverse macrobenthic communities are important habitats for fish. However, detailed information on macrobenthic communities is rarely available and is usually limited to SCUBA diving depths. To establish depth-related distribution patterns and drivers that structure reef communities, the macrobenthos situated in a warm-temperate marine protected area (MPA; 34°01′24S; 23°54′09E) was sampled between 2009 and 2012. Comparison of shallow (11–25 m) and deep (45–75 m) sites revealed significantly different communities, sharing only 27.9 % of species. LINKTREE analysis revealed a changeover of species along the depth gradient, resulting in four significantly different assemblage clusters, each associated with particular environmental variables. High light intensity supported benthic algae at shallow depths, and as light availability decreased with depth, algal cover diminished and was eventually absent from the deep reef. Upright growth forms and settled particulate matter were positively related to depth and dominated the deep reef. Reduced wave action and currents on the deep reef can explain the increased settling of suspended particles. Under such conditions, clogging of feeding parts of the encrusting species is expected, and upright growth would be favoured. Considering that most MPAs are restricted to shallow coastal habitats and that macrobenthic communities change significantly with depth, it is probable that many unique deep reef habitats are currently afforded no protection.
- Full Text:
- Authors: Heyns, E R , Bernard, Anthony T F , Richoux, Nicole B , Götz, A
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457230 , vital:75618 , xlink:href="https://doi.org/10.1007/s00227-016-2816-z"
- Description: Effective marine resource management requires knowledge of the distribution of critical habitats that support resource populations and the processes that maintain them. Reefs that host diverse macrobenthic communities are important habitats for fish. However, detailed information on macrobenthic communities is rarely available and is usually limited to SCUBA diving depths. To establish depth-related distribution patterns and drivers that structure reef communities, the macrobenthos situated in a warm-temperate marine protected area (MPA; 34°01′24S; 23°54′09E) was sampled between 2009 and 2012. Comparison of shallow (11–25 m) and deep (45–75 m) sites revealed significantly different communities, sharing only 27.9 % of species. LINKTREE analysis revealed a changeover of species along the depth gradient, resulting in four significantly different assemblage clusters, each associated with particular environmental variables. High light intensity supported benthic algae at shallow depths, and as light availability decreased with depth, algal cover diminished and was eventually absent from the deep reef. Upright growth forms and settled particulate matter were positively related to depth and dominated the deep reef. Reduced wave action and currents on the deep reef can explain the increased settling of suspended particles. Under such conditions, clogging of feeding parts of the encrusting species is expected, and upright growth would be favoured. Considering that most MPAs are restricted to shallow coastal habitats and that macrobenthic communities change significantly with depth, it is probable that many unique deep reef habitats are currently afforded no protection.
- Full Text:
Design of a Configurable Embedded Network Tap Flow Generation using NetFlow v9 and IPFIX Formats
- Pennefather, Sean, Irwin, Barry V W
- Authors: Pennefather, Sean , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427756 , vital:72460 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622779_Design_of_a_Configurable_Embedded_Network_Tap_Flow_Generation_using_NetFlow_v9_and_IPFIX_Formats/links/5b9a19f2299bf14ad4d6a591/Design-of-a-Configurable-Embedded-Network-Tap-Flow-Generation-using-NetFlow-v9-and-IPFIX-Formats.pdf
- Description: This paper describes the design of a $200 hardware apparatus capable of passively monitoring network transmission at wire speeds of 100Mbit/s and generating NetFlow v9 or IPFIX compliant network flows for a downstream monitoring infrastructure. Testing of the apparatus hardware confirmed no network disruptions regardless of operational or power state while still being capable of correctly monitoring network traffic when configured. System testing under situations of heavy load confirmed apparatus capability at monitoring network traffic and correct generation of network flows compliant with either NetFlow v9 or IPFIX standards.
- Full Text:
- Authors: Pennefather, Sean , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427756 , vital:72460 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622779_Design_of_a_Configurable_Embedded_Network_Tap_Flow_Generation_using_NetFlow_v9_and_IPFIX_Formats/links/5b9a19f2299bf14ad4d6a591/Design-of-a-Configurable-Embedded-Network-Tap-Flow-Generation-using-NetFlow-v9-and-IPFIX-Formats.pdf
- Description: This paper describes the design of a $200 hardware apparatus capable of passively monitoring network transmission at wire speeds of 100Mbit/s and generating NetFlow v9 or IPFIX compliant network flows for a downstream monitoring infrastructure. Testing of the apparatus hardware confirmed no network disruptions regardless of operational or power state while still being capable of correctly monitoring network traffic when configured. System testing under situations of heavy load confirmed apparatus capability at monitoring network traffic and correct generation of network flows compliant with either NetFlow v9 or IPFIX standards.
- Full Text:
Detecting derivative malware samples using deobfuscation-assisted similarity analysis
- Authors: Wrench, Peter Mark
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/383 , vital:19954
- Description: The overwhelming popularity of PHP as a hosting platform has made it the language of choice for developers of Remote Access Trojans (RATs or web shells) and other malicious software. These shells are typically used to compromise and monetise web platforms by providing the attacker with basic remote access to the system, including _le transfer, command execution, network reconnaissance, and database connectivity. Once infected, compromised systems can be used to defraud users by hosting phishing sites, performing Distributed Denial of Service attacks, or serving as anonymous platforms for sending spam or other malfeasance. The vast majority of these threats are largely derivative, incorporating core capabilities found in more established RATs such as c99 and r57. Authors of malicious software routinely produce new shell variants by modifying the behaviours of these ubiquitous RATs, either to add desired functionality or to avoid detection by signature-based detection systems. Once these modified shells are eventually identified (or additional functionality is required), the process of shell adaptation begins again. The end result of this iterative process is a web of separate but related shell variants, many of which are at least partially derived from one of the more popular and influential RATs. In response to the problem outlined above, the author set out to design and implement a system capable of circumventing common obfuscation techniques and identifying derivative malware samples in a given collection. To begin with, a decoder component was developed to syntactically deobfuscate and normalise PHP code by detecting and reversing idiomatic obfuscation constructs, and to apply uniform formatting conventions to all system inputs. A unified malware analysis framework, called Viper, was then extended to create a modular similarity analysis system comprised of individual feature extraction modules, modules responsible for batch processing, a matrix module for comparing sample features, and two visualisation modules capable of generating visual representations of shell similarity. The principal conclusion of the research was that the deobfuscation performed by the decoder component prior to analysis dramatically improved the observed levels of similarity between test samples. This in turn allowed the modular similarity analysis system to identify derivative clusters (or families) within a large collection of shells more accurately. Techniques for isolating and re-rendering these clusters were also developed and demonstrated to be effective at increasing the amount of detail available for evaluating the relative magnitudes of the relationships within each cluster.
- Full Text:
- Authors: Wrench, Peter Mark
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/383 , vital:19954
- Description: The overwhelming popularity of PHP as a hosting platform has made it the language of choice for developers of Remote Access Trojans (RATs or web shells) and other malicious software. These shells are typically used to compromise and monetise web platforms by providing the attacker with basic remote access to the system, including _le transfer, command execution, network reconnaissance, and database connectivity. Once infected, compromised systems can be used to defraud users by hosting phishing sites, performing Distributed Denial of Service attacks, or serving as anonymous platforms for sending spam or other malfeasance. The vast majority of these threats are largely derivative, incorporating core capabilities found in more established RATs such as c99 and r57. Authors of malicious software routinely produce new shell variants by modifying the behaviours of these ubiquitous RATs, either to add desired functionality or to avoid detection by signature-based detection systems. Once these modified shells are eventually identified (or additional functionality is required), the process of shell adaptation begins again. The end result of this iterative process is a web of separate but related shell variants, many of which are at least partially derived from one of the more popular and influential RATs. In response to the problem outlined above, the author set out to design and implement a system capable of circumventing common obfuscation techniques and identifying derivative malware samples in a given collection. To begin with, a decoder component was developed to syntactically deobfuscate and normalise PHP code by detecting and reversing idiomatic obfuscation constructs, and to apply uniform formatting conventions to all system inputs. A unified malware analysis framework, called Viper, was then extended to create a modular similarity analysis system comprised of individual feature extraction modules, modules responsible for batch processing, a matrix module for comparing sample features, and two visualisation modules capable of generating visual representations of shell similarity. The principal conclusion of the research was that the deobfuscation performed by the decoder component prior to analysis dramatically improved the observed levels of similarity between test samples. This in turn allowed the modular similarity analysis system to identify derivative clusters (or families) within a large collection of shells more accurately. Techniques for isolating and re-rendering these clusters were also developed and demonstrated to be effective at increasing the amount of detail available for evaluating the relative magnitudes of the relationships within each cluster.
- Full Text:
Detecting derivative malware samples using deobfuscation-assisted similarity analysis
- Wrench, Peter, Irwin, Barry V W
- Authors: Wrench, Peter , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429494 , vital:72617 , 10.23919/SAIEE.2016.8531543
- Description: The abundance of PHP-based Remote Access Trojans (or web shells) found in the wild has led malware researchers to develop systems capable of tracking and analysing these shells. In the past, such shells were ably classified using signature matching, a process that is currently unable to cope with the sheer volume and variety of web-based malware in circulation. Although a large percentage of newly-created webshell software incorporates portions of code derived from seminal shells such as c99 and r57, they are able to disguise this by making extensive use of obfuscation techniques intended to frustrate any attempts to dissect or reverse engineer the code. This paper presents an approach to shell classification and analysis (based on similarity to a body of known malware) in an attempt to create a comprehensive taxonomy of PHP-based web shells. Several different measures of similarity were used in conjunction with clustering algorithms and visualisation techniques in order to achieve this. Furthermore, an auxiliary component capable of syntactically deobfuscating PHP code is described. This was employed to reverse idiomatic obfuscation constructs used by software authors. It was found that this deobfuscation dramatically increased the observed levels of similarity by exposing additional code for analysis.
- Full Text:
- Authors: Wrench, Peter , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429494 , vital:72617 , 10.23919/SAIEE.2016.8531543
- Description: The abundance of PHP-based Remote Access Trojans (or web shells) found in the wild has led malware researchers to develop systems capable of tracking and analysing these shells. In the past, such shells were ably classified using signature matching, a process that is currently unable to cope with the sheer volume and variety of web-based malware in circulation. Although a large percentage of newly-created webshell software incorporates portions of code derived from seminal shells such as c99 and r57, they are able to disguise this by making extensive use of obfuscation techniques intended to frustrate any attempts to dissect or reverse engineer the code. This paper presents an approach to shell classification and analysis (based on similarity to a body of known malware) in an attempt to create a comprehensive taxonomy of PHP-based web shells. Several different measures of similarity were used in conjunction with clustering algorithms and visualisation techniques in order to achieve this. Furthermore, an auxiliary component capable of syntactically deobfuscating PHP code is described. This was employed to reverse idiomatic obfuscation constructs used by software authors. It was found that this deobfuscation dramatically increased the observed levels of similarity by exposing additional code for analysis.
- Full Text:
Detection of plant growth enhancing features in psychrotolerant yeasts from Patagonia (Argentina)
- Mestre, María C, Fontenla, Sonia, Bruzone, Marie C, Fernández, Natalia V, Dames, Joanna F
- Authors: Mestre, María C , Fontenla, Sonia , Bruzone, Marie C , Fernández, Natalia V , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448581 , vital:74744 , https://doi.org/10.1002/jobm.201500728
- Description: This study explores the biotechnological potential for plant production of twelve psychrotolerant yeasts strains from Northwest‐Patagonia. These strains were isolated from different substrates associated with Nothofagus sp. in native forests and Vaccinium sp. in a commercial plantation. Yeasts characterization was performed using in vitro assays to evaluate the production of auxin‐like compounds and siderophores, ability to solubilize inorganic phosphate and to reduce common plant pathogen growth. Strain YF8.3 identified as Aureobasidium pullullans was the main producer of auxin‐like and siderophores compounds. Phosphate solubilization was a characteristic observed by strains L8.12 and CRUB1775 identified as Holtermaniella takashimae and Candida maritima, respectively. Different yeast strains were able to inhibit the growth of Verticillium dahliae PPRI5569 and Pythium aphanidermatum PPRI 9009, but they all failed to inhibit the growth of Fusarium oxysporum PPRI5457. The present study, suggests that yeasts present in different environments in Northwestern‐Patagonian have physiological in vitro features which may influence plant growth. These results are promising for the developing of biological products based on Patagonian yeasts for plant production in cold‐temperate regions.
- Full Text:
- Authors: Mestre, María C , Fontenla, Sonia , Bruzone, Marie C , Fernández, Natalia V , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448581 , vital:74744 , https://doi.org/10.1002/jobm.201500728
- Description: This study explores the biotechnological potential for plant production of twelve psychrotolerant yeasts strains from Northwest‐Patagonia. These strains were isolated from different substrates associated with Nothofagus sp. in native forests and Vaccinium sp. in a commercial plantation. Yeasts characterization was performed using in vitro assays to evaluate the production of auxin‐like compounds and siderophores, ability to solubilize inorganic phosphate and to reduce common plant pathogen growth. Strain YF8.3 identified as Aureobasidium pullullans was the main producer of auxin‐like and siderophores compounds. Phosphate solubilization was a characteristic observed by strains L8.12 and CRUB1775 identified as Holtermaniella takashimae and Candida maritima, respectively. Different yeast strains were able to inhibit the growth of Verticillium dahliae PPRI5569 and Pythium aphanidermatum PPRI 9009, but they all failed to inhibit the growth of Fusarium oxysporum PPRI5457. The present study, suggests that yeasts present in different environments in Northwestern‐Patagonian have physiological in vitro features which may influence plant growth. These results are promising for the developing of biological products based on Patagonian yeasts for plant production in cold‐temperate regions.
- Full Text:
Developing a lean and green manufacturing plan for the newspaper printing industry - considering the Rising Sun Printers
- Authors: Maharaj, Avish
- Date: 2016
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:867 , http://hdl.handle.net/10962/d1021249
- Description: This research is focused on lean and green manufacturing using a printing company in South Africa as a case study focusing on their printing division. The reason for addressing the printing division of the company was to develop a lean and green manufacturing plan to address the concerns of resource utilisation and waste disposal in the printing division. The research looked at the concept of lean and green individually as well as together and by analysing the relationship between the two concepts. The outcome was that environmental “green” waste is embedded in the seven types of lean waste which is overproduction, waiting, transport, inappropriate processing, unnecessary inventory, unnecessary motion and waste due to defects (Moreira, Alves and Sousa, 2010 cited in Pampanelli, Found and Bernardes, 2014). It was found that the company under consideration had not been familiar with these concepts but learnt and understood the value it could bring to the company. The research concludes with the plan using the 5S tool to reduce the seven types of waste linked to lean and green manufacturing.
- Full Text:
- Authors: Maharaj, Avish
- Date: 2016
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:867 , http://hdl.handle.net/10962/d1021249
- Description: This research is focused on lean and green manufacturing using a printing company in South Africa as a case study focusing on their printing division. The reason for addressing the printing division of the company was to develop a lean and green manufacturing plan to address the concerns of resource utilisation and waste disposal in the printing division. The research looked at the concept of lean and green individually as well as together and by analysing the relationship between the two concepts. The outcome was that environmental “green” waste is embedded in the seven types of lean waste which is overproduction, waiting, transport, inappropriate processing, unnecessary inventory, unnecessary motion and waste due to defects (Moreira, Alves and Sousa, 2010 cited in Pampanelli, Found and Bernardes, 2014). It was found that the company under consideration had not been familiar with these concepts but learnt and understood the value it could bring to the company. The research concludes with the plan using the 5S tool to reduce the seven types of waste linked to lean and green manufacturing.
- Full Text:
Developing a Multi Platform Countermeasure to Ensure a Secure Home
- Frieslaar, Ibraheem, Irwin, Barry V W
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427772 , vital:72461 , https://www.researchgate.net/profile/Ibraheem-Fries-laar/publication/312219190_Developing_a_Multi_Platform_Countermeasure_to_Ensure_a_Secure_Home/links/587747d508ae8fce492fb5e2/Developing-a-Multi-Platform-Countermeasure-to-Ensure-a-Secure-Home.pdf
- Description: This research proposes an investigation into the side channel analysis attacks against the AES algorithm on high powered devices. Currently the research field into this aspect is fairly new and there is room for more information to be discovered. This research proposes using a Raspberry Pi in conjunction with a Software Defined Radio to capture electromagnetic emanations in the low and high frequency domains. Two well-known side channel attacks will be used to recover the secret information based on the electromagnetic emanations. Furthermore, this research proposes investigating into a possible software countermeasure by using the high-powered devices features such as multi-threading.
- Full Text:
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427772 , vital:72461 , https://www.researchgate.net/profile/Ibraheem-Fries-laar/publication/312219190_Developing_a_Multi_Platform_Countermeasure_to_Ensure_a_Secure_Home/links/587747d508ae8fce492fb5e2/Developing-a-Multi-Platform-Countermeasure-to-Ensure-a-Secure-Home.pdf
- Description: This research proposes an investigation into the side channel analysis attacks against the AES algorithm on high powered devices. Currently the research field into this aspect is fairly new and there is room for more information to be discovered. This research proposes using a Raspberry Pi in conjunction with a Software Defined Radio to capture electromagnetic emanations in the low and high frequency domains. Two well-known side channel attacks will be used to recover the secret information based on the electromagnetic emanations. Furthermore, this research proposes investigating into a possible software countermeasure by using the high-powered devices features such as multi-threading.
- Full Text: