Investigating the effects various compilers have on the electromagnetic signature of a cryptographic executable
- Frieslaar, Ibraheem, Irwin, Barry V W
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430207 , vital:72673 , https://doi.org/10.1145/3129416.3129436
- Description: This research investigates changes in the electromagnetic (EM) signatures of a cryptographic binary executable based on compile-time parameters to the GNU and clang compilers. The source code was compiled and executed on a Raspberry Pi 2, which utilizes the ARMv7 CPU. Various optimization flags are enabled at compile-time and the output of the binary executable's EM signatures are captured at run-time. It is demonstrated that GNU and clang compilers produced different EM signature on program execution. The results indicated while utilizing the O3 optimization flag, the EM signature of the program changes. Additionally, the g++ compiler demonstrated fewer instructions were required to run the executable; this related to fewer EM emissions leaked. The EM data from the various compilers under different optimization levels was used as input data for a correlation power analysis attack. The results indicated that partial AES-128 encryption keys was possible. In addition, the fewest subkeys recovered was when the clang compiler was used with level O2 optimization. Finally, the research was able to recover 15 of 16 AES-128 cryptographic algorithm's subkeys, from the the Pi.
- Full Text:
- Date Issued: 2017
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430207 , vital:72673 , https://doi.org/10.1145/3129416.3129436
- Description: This research investigates changes in the electromagnetic (EM) signatures of a cryptographic binary executable based on compile-time parameters to the GNU and clang compilers. The source code was compiled and executed on a Raspberry Pi 2, which utilizes the ARMv7 CPU. Various optimization flags are enabled at compile-time and the output of the binary executable's EM signatures are captured at run-time. It is demonstrated that GNU and clang compilers produced different EM signature on program execution. The results indicated while utilizing the O3 optimization flag, the EM signature of the program changes. Additionally, the g++ compiler demonstrated fewer instructions were required to run the executable; this related to fewer EM emissions leaked. The EM data from the various compilers under different optimization levels was used as input data for a correlation power analysis attack. The results indicated that partial AES-128 encryption keys was possible. In addition, the fewest subkeys recovered was when the clang compiler was used with level O2 optimization. Finally, the research was able to recover 15 of 16 AES-128 cryptographic algorithm's subkeys, from the the Pi.
- Full Text:
- Date Issued: 2017
Investigating the electromagnetic side channel leakage from a raspberry pi
- Frieslaar, Ibraheem, Irwin, Barry V W
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429548 , vital:72621 , https://ieeexplore.ieee.org/abstract/document/8251771
- Description: This research investigates the Electromagnetic (EM) side channel leakage of a Raspberry Pi 2 B+. An evaluation is performed on the EM leakage as the device executes the AES-128 cryptographic algorithm contained in the Crypto++ library in a threaded environment. Four multi-threaded implementations are evaluated. These implementations are Portable Operating System Interface Threads, C++11 threads, Threading Building Blocks, and OpenMP threads. It is demonstrated that the various thread techniques have distinct variations in frequency and shape as EM emanations is leaked from the Raspberry Pi. Additionally, noise is introduced while the cryptographic algorithm executes. The results indicates that tt is still possible to visibly see the execution of the cryptographic algorithm. However, out of 50 occasions the cryptographic execution was not detected 32 times. It was further identified when calculating prime numbers, the cryptographic algorithm becomes hidden. Furthermore, the analysis pointed in the direction that when high prime numbers are calculated there is a window where the cryptographic algorithm can not be seen visibly in the EM spectrum.
- Full Text:
- Date Issued: 2017
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429548 , vital:72621 , https://ieeexplore.ieee.org/abstract/document/8251771
- Description: This research investigates the Electromagnetic (EM) side channel leakage of a Raspberry Pi 2 B+. An evaluation is performed on the EM leakage as the device executes the AES-128 cryptographic algorithm contained in the Crypto++ library in a threaded environment. Four multi-threaded implementations are evaluated. These implementations are Portable Operating System Interface Threads, C++11 threads, Threading Building Blocks, and OpenMP threads. It is demonstrated that the various thread techniques have distinct variations in frequency and shape as EM emanations is leaked from the Raspberry Pi. Additionally, noise is introduced while the cryptographic algorithm executes. The results indicates that tt is still possible to visibly see the execution of the cryptographic algorithm. However, out of 50 occasions the cryptographic execution was not detected 32 times. It was further identified when calculating prime numbers, the cryptographic algorithm becomes hidden. Furthermore, the analysis pointed in the direction that when high prime numbers are calculated there is a window where the cryptographic algorithm can not be seen visibly in the EM spectrum.
- Full Text:
- Date Issued: 2017
Investigating the utilization of the secure hash algorithm to generate electromagnetic noise
- Frieslaar, Ibraheem, Irwin, Barry V W
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430222 , vital:72674 , https://doi.org/10.1145/3163080.3163089
- Description: This research introduces an electromagnetic (EM) noise generator known as the FRIES noise generator to mitigate and obfuscate Side Channel Analysis (SCA) attacks against a Raspberry Pi. The FRIES noise generator utilizes the implementation of the Secure Hash Algorithm (SHA) from OpenSSL to generate white noise within the EM spectrum. This research further contributes to the body of knowledge by demonstrating that the SHA implementation of libcrypto++ and OpenSSL had different EM signatures. It was further revealed that as a more secure implementation of the SHA was executed additional data lines were used, resulting in increased EM emissions. It was demonstrated that the OpenSSL implementations of the SHA was more optimized as opposed to the libcrypto++ implementation by utilizing less resources and not leaving the device in a bottleneck. The FRIES daemon added noise to the EM leakage which prevents the visual location of the AES-128 cryptographic implementation. Finally, the cross-correlation test demonstrated that the EM features of the AES-128 algorithm was not detected within the FRIES noise.
- Full Text:
- Date Issued: 2017
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430222 , vital:72674 , https://doi.org/10.1145/3163080.3163089
- Description: This research introduces an electromagnetic (EM) noise generator known as the FRIES noise generator to mitigate and obfuscate Side Channel Analysis (SCA) attacks against a Raspberry Pi. The FRIES noise generator utilizes the implementation of the Secure Hash Algorithm (SHA) from OpenSSL to generate white noise within the EM spectrum. This research further contributes to the body of knowledge by demonstrating that the SHA implementation of libcrypto++ and OpenSSL had different EM signatures. It was further revealed that as a more secure implementation of the SHA was executed additional data lines were used, resulting in increased EM emissions. It was demonstrated that the OpenSSL implementations of the SHA was more optimized as opposed to the libcrypto++ implementation by utilizing less resources and not leaving the device in a bottleneck. The FRIES daemon added noise to the EM leakage which prevents the visual location of the AES-128 cryptographic implementation. Finally, the cross-correlation test demonstrated that the EM features of the AES-128 algorithm was not detected within the FRIES noise.
- Full Text:
- Date Issued: 2017
Investigation of photophysicochemical properties of zinc phthalocyanines conjugated to metallic nanoparticles
- Dube, Edith, Nwaji, Njemuwa, Oluwole, David O, Mack, John, Nyokong, Tebello
- Authors: Dube, Edith , Nwaji, Njemuwa , Oluwole, David O , Mack, John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233425 , vital:50089 , xlink:href="https://doi.org/10.1016/j.jphotochem.2017.09.020"
- Description: The syntheses of zinc(II) tetra–[3–(4–phenoxy) (propanoic acid) phthalocyanine] (2) and zinc(II) mono–[3–(4–phenoxy) (propanoic acid) phthalocyanine (3) are reported in this work. Compounds 2 and 3 were covalently linked to glutathione capped silver (AgNPs–GSH), gold (AuNPs–GSH) and silver-gold alloy (Ag3Au1NPs–GSH) nanoparticles (NPs) via an amide bond formation to afford the conjugates: 2–AgNPs–GSH, 3–AgNPs–GSH, 2–AuNPs–GSH, 3–AuNPs–GSH, 2-Ag3Au1NPs–GSH and 3-Ag3Au1NPs–GSH. The photophysicochemical behaviours of the compounds and their conjugates with NPs were assessed in solution. The conjugates afforded a decrease in fluorescence quantum yields and lifetimes with improved triplet quantum yields in comparison to the compounds. Accordingly, the AgNPs and AuNPs conjugates with the compounds afforded high singlet quantum yields. On the contrary, the conjugates of the alloy afforded decreased singlet quantum yields probably due to the screening effect. The compounds and their conjugates with NPs could serve as a viable and efficacious photosensitizer for photodynamic therapy.
- Full Text:
- Date Issued: 2017
- Authors: Dube, Edith , Nwaji, Njemuwa , Oluwole, David O , Mack, John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233425 , vital:50089 , xlink:href="https://doi.org/10.1016/j.jphotochem.2017.09.020"
- Description: The syntheses of zinc(II) tetra–[3–(4–phenoxy) (propanoic acid) phthalocyanine] (2) and zinc(II) mono–[3–(4–phenoxy) (propanoic acid) phthalocyanine (3) are reported in this work. Compounds 2 and 3 were covalently linked to glutathione capped silver (AgNPs–GSH), gold (AuNPs–GSH) and silver-gold alloy (Ag3Au1NPs–GSH) nanoparticles (NPs) via an amide bond formation to afford the conjugates: 2–AgNPs–GSH, 3–AgNPs–GSH, 2–AuNPs–GSH, 3–AuNPs–GSH, 2-Ag3Au1NPs–GSH and 3-Ag3Au1NPs–GSH. The photophysicochemical behaviours of the compounds and their conjugates with NPs were assessed in solution. The conjugates afforded a decrease in fluorescence quantum yields and lifetimes with improved triplet quantum yields in comparison to the compounds. Accordingly, the AgNPs and AuNPs conjugates with the compounds afforded high singlet quantum yields. On the contrary, the conjugates of the alloy afforded decreased singlet quantum yields probably due to the screening effect. The compounds and their conjugates with NPs could serve as a viable and efficacious photosensitizer for photodynamic therapy.
- Full Text:
- Date Issued: 2017
Isolation, characterization and antiproliferative activity of new metabolites from the South African endemic red algal species Laurencia alfredensis
- Dziwornu, Godwin A, Caira, Mino R, de la Mare, Jo-Anne, Edkins, Adrienne L, Bolton, John J, Beukes, Denzil R, Sunassee, Suthananda N
- Authors: Dziwornu, Godwin A , Caira, Mino R , de la Mare, Jo-Anne , Edkins, Adrienne L , Bolton, John J , Beukes, Denzil R , Sunassee, Suthananda N
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59963 , vital:27715 , https://doi:10.3390/molecules22040513
- Description: The marine red algae of the genus Laurencia have been widely studied for their structurally diverse and biologically active secondary metabolites. We report here the natural product investigation of the organic extract of a newly identified South African endemic species, Laurencia alfredensis. A sequence of column chromatography, preparative TLC and normal phase HPLC resulted in the isolation of eleven compounds comprising three labdane-type diterpenes (1-3), four polyether triterpenes (4-7), three cholestane-type ecdysteroids (8-10) and a glycolipid (11). Compounds 1-3, 5-8 and 10 have not previously been reported, while compound 9 is reported here for the first time from a natural source and the known compound 11 isolated for the first time from the genus Laurencia. The structural elucidation and the relative configuration assignments of the compounds were accomplished by extensive use of ID- and 2D-NMR, HR-ESI-MS, UV and IR spectroscopic techniques, while the absolute configuration of compound 1 was determined by single-crystal X-ray diffraction analysis. All compounds were evaluated against the MDA-MB-231 breast and HeLa cervical cancer cell lines. Compound 2 exhibited low micromolar antiproliferative activity (IC50 = 9.3 gM) against the triple negative breast carcinoma and compound 7 was similarly active (IC50 = 8.8 gM) against the cervical cancer cell line.
- Full Text:
- Date Issued: 2017
- Authors: Dziwornu, Godwin A , Caira, Mino R , de la Mare, Jo-Anne , Edkins, Adrienne L , Bolton, John J , Beukes, Denzil R , Sunassee, Suthananda N
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59963 , vital:27715 , https://doi:10.3390/molecules22040513
- Description: The marine red algae of the genus Laurencia have been widely studied for their structurally diverse and biologically active secondary metabolites. We report here the natural product investigation of the organic extract of a newly identified South African endemic species, Laurencia alfredensis. A sequence of column chromatography, preparative TLC and normal phase HPLC resulted in the isolation of eleven compounds comprising three labdane-type diterpenes (1-3), four polyether triterpenes (4-7), three cholestane-type ecdysteroids (8-10) and a glycolipid (11). Compounds 1-3, 5-8 and 10 have not previously been reported, while compound 9 is reported here for the first time from a natural source and the known compound 11 isolated for the first time from the genus Laurencia. The structural elucidation and the relative configuration assignments of the compounds were accomplished by extensive use of ID- and 2D-NMR, HR-ESI-MS, UV and IR spectroscopic techniques, while the absolute configuration of compound 1 was determined by single-crystal X-ray diffraction analysis. All compounds were evaluated against the MDA-MB-231 breast and HeLa cervical cancer cell lines. Compound 2 exhibited low micromolar antiproliferative activity (IC50 = 9.3 gM) against the triple negative breast carcinoma and compound 7 was similarly active (IC50 = 8.8 gM) against the cervical cancer cell line.
- Full Text:
- Date Issued: 2017
Isolation, identification and genetic characterisation of a microsporidium isolated from carob moth, Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae)
- Lloyd, Melissa, Knox, Caroline M, Hill, Martin P, Moore, Sean D
- Authors: Lloyd, Melissa , Knox, Caroline M , Hill, Martin P , Moore, Sean D
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59874 , vital:27674 , https://doi.org/10.4001/003.025.0529
- Description: 'Microsporidia' is a term used for organisms belonging to the phylum Microspora, which contains approximately 187 genera and 1500 species (Corradi 2015). They are obligate intracellular parasites with no active metabolic stages of the life cycle occurring outside of the host cells (Franzen & Muller 1999; Garcia 2002; Tsai et al. 2003; Huang et al. 2004). They exhibit eukaryotic characteristics such as a membrane-bound nucleus, an intracytoplasmic membrane system, and chromosome separation occurs on mitotic spindles. However, they also exhibit prokaryotic characteristics such as possession of a 70S ribosome, lack of true mitochondria and peroxisomes, a simple version of the Golgi apparatus, and a small genome which is much less complex than those of most eukaryotes (Franzen & Muller 1999; Garcia 2002). Microspo- ridia are parasitic in all major groups of animals, both vertebrates and invertebrates (Sprague 1977; Franzen & Muller 1999). Microsporidia were first recognised as pathogens in silkworms by Nageli (1857), and now have been found to infect many hosts such as humans, insects, fish and mammals (Stentiford et al. 2016).
- Full Text:
- Date Issued: 2017
- Authors: Lloyd, Melissa , Knox, Caroline M , Hill, Martin P , Moore, Sean D
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59874 , vital:27674 , https://doi.org/10.4001/003.025.0529
- Description: 'Microsporidia' is a term used for organisms belonging to the phylum Microspora, which contains approximately 187 genera and 1500 species (Corradi 2015). They are obligate intracellular parasites with no active metabolic stages of the life cycle occurring outside of the host cells (Franzen & Muller 1999; Garcia 2002; Tsai et al. 2003; Huang et al. 2004). They exhibit eukaryotic characteristics such as a membrane-bound nucleus, an intracytoplasmic membrane system, and chromosome separation occurs on mitotic spindles. However, they also exhibit prokaryotic characteristics such as possession of a 70S ribosome, lack of true mitochondria and peroxisomes, a simple version of the Golgi apparatus, and a small genome which is much less complex than those of most eukaryotes (Franzen & Muller 1999; Garcia 2002). Microspo- ridia are parasitic in all major groups of animals, both vertebrates and invertebrates (Sprague 1977; Franzen & Muller 1999). Microsporidia were first recognised as pathogens in silkworms by Nageli (1857), and now have been found to infect many hosts such as humans, insects, fish and mammals (Stentiford et al. 2016).
- Full Text:
- Date Issued: 2017
Journal development, scholar development and quality
- Rosenberg, Eureta, Togo, Muchaiteyi
- Authors: Rosenberg, Eureta , Togo, Muchaiteyi
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67314 , vital:29072 , https://doi.org/10.4314/SAJEE.V.33I1.1
- Description: publisher version , In reflecting on the contributions to Volume 33, it is evident that a variety of theories about learning and social change inform the scholars in environmental education, ranging from behaviourist, to social behavioural, constructivist and social constructivist learning theories, social and critical realism, and more. What unites these papers is a shared concern about learning in relation to the future well-being of the planet and its people. New scholars entering the field of environmental and sustainability education have the task of mastering not only the social– ecological subject matter of the field, but also their chosen learning theories. In this regard, drawing on the back copies of the SAJEE can be of great value. Much research and writing has already been done on curriculum, education and learning inside and outside of formal institutions, yet many more questions remain. The field is best advanced by noting and building on, challenging and advancing past studies and existing scholarship. The fact that all 33 Volumes of the SAJEE are available online, just a ‘few clicks away’ from any student or supervisor with Internet access, is therefore an enormous boon. We encourage readers and future authors to draw on the work in this and other environmental education journals as they conceptualise, design and reflect on their own studies.
- Full Text:
- Date Issued: 2017
- Authors: Rosenberg, Eureta , Togo, Muchaiteyi
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67314 , vital:29072 , https://doi.org/10.4314/SAJEE.V.33I1.1
- Description: publisher version , In reflecting on the contributions to Volume 33, it is evident that a variety of theories about learning and social change inform the scholars in environmental education, ranging from behaviourist, to social behavioural, constructivist and social constructivist learning theories, social and critical realism, and more. What unites these papers is a shared concern about learning in relation to the future well-being of the planet and its people. New scholars entering the field of environmental and sustainability education have the task of mastering not only the social– ecological subject matter of the field, but also their chosen learning theories. In this regard, drawing on the back copies of the SAJEE can be of great value. Much research and writing has already been done on curriculum, education and learning inside and outside of formal institutions, yet many more questions remain. The field is best advanced by noting and building on, challenging and advancing past studies and existing scholarship. The fact that all 33 Volumes of the SAJEE are available online, just a ‘few clicks away’ from any student or supervisor with Internet access, is therefore an enormous boon. We encourage readers and future authors to draw on the work in this and other environmental education journals as they conceptualise, design and reflect on their own studies.
- Full Text:
- Date Issued: 2017
JSON schema for attribute-based access control for network resource security
- Linklater, Gregory, Smith, Christian, Connan, James, Herbert, Alan, Irwin, Barry V W
- Authors: Linklater, Gregory , Smith, Christian , Connan, James , Herbert, Alan , Irwin, Barry V W
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428368 , vital:72506 , https://researchspace.csir.co.za/dspace/bitstream/handle/10204/9820/Linklater_19660_2017.pdf?sequence=1andisAllowed=y
- Description: Attribute-based Access Control (ABAC) is an access control model where authorization for an action on a resource is determined by evalu-ating attributes of the subject, resource (object) and environment. The attributes are evaluated against boolean rules of varying complexity. ABAC rule languages are often based on serializable object modeling and schema languages as in the case of XACML which is based on XML Schema. XACML is a standard by OASIS, and is the current de facto standard for ABAC. While a JSON profile for XACML exists, it is simply a compatibility layer for using JSON in XACML which caters to the XML object model paradigm, as opposed to the JSON object model paradigm. This research proposes JSON Schema as a modeling lan-guage that caters to the JSON object model paradigm on which to base an ABAC rule language. It continues to demonstrate its viability for the task by comparison against the features provided to XACML by XML Schema.
- Full Text:
- Date Issued: 2017
- Authors: Linklater, Gregory , Smith, Christian , Connan, James , Herbert, Alan , Irwin, Barry V W
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428368 , vital:72506 , https://researchspace.csir.co.za/dspace/bitstream/handle/10204/9820/Linklater_19660_2017.pdf?sequence=1andisAllowed=y
- Description: Attribute-based Access Control (ABAC) is an access control model where authorization for an action on a resource is determined by evalu-ating attributes of the subject, resource (object) and environment. The attributes are evaluated against boolean rules of varying complexity. ABAC rule languages are often based on serializable object modeling and schema languages as in the case of XACML which is based on XML Schema. XACML is a standard by OASIS, and is the current de facto standard for ABAC. While a JSON profile for XACML exists, it is simply a compatibility layer for using JSON in XACML which caters to the XML object model paradigm, as opposed to the JSON object model paradigm. This research proposes JSON Schema as a modeling lan-guage that caters to the JSON object model paradigm on which to base an ABAC rule language. It continues to demonstrate its viability for the task by comparison against the features provided to XACML by XML Schema.
- Full Text:
- Date Issued: 2017
Justin Davy of Burning Museum: an interview
- Authors: Dantas, Nancy
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147070 , vital:38590 , https://www.on-curating.org/issue-32-reader/justin-davy-of-the-burning-museum.html#.Xs0mCmgzbIU
- Description: The Burning Museum is an arts collective based in Cape Town, South Africa. This interview is the result of a three-part Skype conversation between Justin Davy of the Burning Museum and Nancy Dantas, an independent curator and researcher with an interest in recovering the neglected and overlooked exhibition histories and practices of the south.
- Full Text:
- Date Issued: 2017
- Authors: Dantas, Nancy
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147070 , vital:38590 , https://www.on-curating.org/issue-32-reader/justin-davy-of-the-burning-museum.html#.Xs0mCmgzbIU
- Description: The Burning Museum is an arts collective based in Cape Town, South Africa. This interview is the result of a three-part Skype conversation between Justin Davy of the Burning Museum and Nancy Dantas, an independent curator and researcher with an interest in recovering the neglected and overlooked exhibition histories and practices of the south.
- Full Text:
- Date Issued: 2017
Laser induced photodegradation of Orange G using phthalocyanine–cobalt ferrite magnetic nanoparticle conjugates electrospun in polystyrene nanofibers
- Mapukata, Sivuyisiwe, Chindeka, Francis, Sekhosana, Kutloano E, Nyokong, Tebello
- Authors: Mapukata, Sivuyisiwe , Chindeka, Francis , Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188617 , vital:44769 , xlink:href="https://doi.org/10.1016/j.mcat.2017.06.028"
- Description: Conjugates of zinc tetracarboxyphenoxy phthalocyanine (ZnTCPPc) and zinc tetraaminophenoxy phthalocyanine (ZnTAPPc) with amine and carboxyl functionalised cobalt ferrite magnetic nanoparticles (CoFe2O4 MNPs), respectively were electrospun into polystyrene (PS) fibers. The resulting composites; ZnTCPPc-CoFe2O4/PS and ZnTAPPc-CoFe2O4/PS were compared based on their photophysical properties and photocatalytic efficiencies in degrading Orange G (OG) using laser as the photoexcitation source. The photocatalytic efficiencies of ZnTCPPc-CoFe2O4/PS and ZnTAPPc-CoFe2O4/PS were compared based on them having different lengths in the linkage chains between the Pcs and CoFe2O4 MNPs and different sizes. Covalent linkage of the Pcs to the CoFe2O4 MNPs enhanced the singlet oxygen and reactive oxygen species (ROS) production of the Pcs and CoFe2O4, respectively hence ZnTCPPc-CoFe2O4/PS and ZnTAPPc-CoFe2O4/PS were found to be more effective photocatalysts than their respective Pcs and CoFe2O4 MNPs. Moreover, the kinetic analyses of the photodecomposition of OG showed that the degradation was in agreement with both pseudo-first order kinetics and followed the Langmuir–Hinshelwood model.
- Full Text:
- Date Issued: 2017
- Authors: Mapukata, Sivuyisiwe , Chindeka, Francis , Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188617 , vital:44769 , xlink:href="https://doi.org/10.1016/j.mcat.2017.06.028"
- Description: Conjugates of zinc tetracarboxyphenoxy phthalocyanine (ZnTCPPc) and zinc tetraaminophenoxy phthalocyanine (ZnTAPPc) with amine and carboxyl functionalised cobalt ferrite magnetic nanoparticles (CoFe2O4 MNPs), respectively were electrospun into polystyrene (PS) fibers. The resulting composites; ZnTCPPc-CoFe2O4/PS and ZnTAPPc-CoFe2O4/PS were compared based on their photophysical properties and photocatalytic efficiencies in degrading Orange G (OG) using laser as the photoexcitation source. The photocatalytic efficiencies of ZnTCPPc-CoFe2O4/PS and ZnTAPPc-CoFe2O4/PS were compared based on them having different lengths in the linkage chains between the Pcs and CoFe2O4 MNPs and different sizes. Covalent linkage of the Pcs to the CoFe2O4 MNPs enhanced the singlet oxygen and reactive oxygen species (ROS) production of the Pcs and CoFe2O4, respectively hence ZnTCPPc-CoFe2O4/PS and ZnTAPPc-CoFe2O4/PS were found to be more effective photocatalysts than their respective Pcs and CoFe2O4 MNPs. Moreover, the kinetic analyses of the photodecomposition of OG showed that the degradation was in agreement with both pseudo-first order kinetics and followed the Langmuir–Hinshelwood model.
- Full Text:
- Date Issued: 2017
Learning affordances and participation enablers within a primary mathematics in-service community of practice:
- Graven, Mellony, Pausigere, Peter
- Authors: Graven, Mellony , Pausigere, Peter
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144622 , vital:38363 , https://sajce.co.za/index.php/sajce/article/view/551
- Description: This article investigates the participation enablers and learning affordances identified by teachers through participation within an in-service community of practice (CoP) of primary teachers called the Numeracy Inquiry Community of Leader Educators (NICLE) in the Eastern Cape. The article draws on three qualitative sources of data: the annual teacher questionnaires of 42 participating teachers, interview data from 8 of the 42 sampled teachers and reflective journal entries of these 8 teachers over the first 2 years of NICLE. All three data sets point to teachers foregrounding the affordances and enablers of NICLE participation across the fundamental elements of a CoP, namely domain, community and practice. We illuminate the way in which teachers' identification of learning affordances relates to these three structural features of a CoP. In concluding, we argue that explicit consideration of these structural elements, and their interrelationship in the design of in-service programmes, could enable clearer articulation of programme aspects and support reflection on the coherence between teacher feedback on these as programmes evolve.
- Full Text:
- Date Issued: 2017
- Authors: Graven, Mellony , Pausigere, Peter
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144622 , vital:38363 , https://sajce.co.za/index.php/sajce/article/view/551
- Description: This article investigates the participation enablers and learning affordances identified by teachers through participation within an in-service community of practice (CoP) of primary teachers called the Numeracy Inquiry Community of Leader Educators (NICLE) in the Eastern Cape. The article draws on three qualitative sources of data: the annual teacher questionnaires of 42 participating teachers, interview data from 8 of the 42 sampled teachers and reflective journal entries of these 8 teachers over the first 2 years of NICLE. All three data sets point to teachers foregrounding the affordances and enablers of NICLE participation across the fundamental elements of a CoP, namely domain, community and practice. We illuminate the way in which teachers' identification of learning affordances relates to these three structural features of a CoP. In concluding, we argue that explicit consideration of these structural elements, and their interrelationship in the design of in-service programmes, could enable clearer articulation of programme aspects and support reflection on the coherence between teacher feedback on these as programmes evolve.
- Full Text:
- Date Issued: 2017
Listening and the ambiguities of voice in South African journalism:
- Garman, Anthea, Malila, Vanessa
- Authors: Garman, Anthea , Malila, Vanessa
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158394 , vital:40180 , https://doi.org/10.1080/02500167.2016.1226914
- Description: Political theorists like Bickford (1996) and media theorists like Couldry (2006) have introduced the concept of listening as a complement to long-standing discussions about voice in democracies and in the media which serve the democratic project. This enhanced understanding of voice goes beyond just hearing into giving serious attention to, in particular, marginalised voices. This article reports on an investigation into the ways in which mainstream and community media in the Eastern Cape, South Africa, understand listening as an important part of their role as journalists. Interviews probed the attitudes of journalists and editors towards listening, and also interrogated their own understandings of their role in South Africa, particularly in relation to young people who are finding their political “voice”.
- Full Text:
- Date Issued: 2017
- Authors: Garman, Anthea , Malila, Vanessa
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158394 , vital:40180 , https://doi.org/10.1080/02500167.2016.1226914
- Description: Political theorists like Bickford (1996) and media theorists like Couldry (2006) have introduced the concept of listening as a complement to long-standing discussions about voice in democracies and in the media which serve the democratic project. This enhanced understanding of voice goes beyond just hearing into giving serious attention to, in particular, marginalised voices. This article reports on an investigation into the ways in which mainstream and community media in the Eastern Cape, South Africa, understand listening as an important part of their role as journalists. Interviews probed the attitudes of journalists and editors towards listening, and also interrogated their own understandings of their role in South Africa, particularly in relation to young people who are finding their political “voice”.
- Full Text:
- Date Issued: 2017
Local knowledge on the uses, habitat, and change in abundance of multipurpose mimusops species in Benin
- Sinasson Gisèle K, Shackleton, Charlie M, Assogbadjo, Achille E, Sinsin, Brice
- Authors: Sinasson Gisèle K , Shackleton, Charlie M , Assogbadjo, Achille E , Sinsin, Brice
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181105 , vital:43699 , xlink:href="https://doi.org/10.1007/s12231-017-9370-6"
- Description: Multipurpose NTFP species typically experience higher harvest demand because of their multiple uses, which, when combined with unsustainable land use practices, may threaten population viability. We assessed local knowledge on the uses, habitat, and population status of Mimusops andongensis and Mimusops kummel, both multipurpose NTFP species in Benin, to promote their valorization and conservation and thus sustain local knowledge on their uses for domestication issues. One hundred households were randomly selected for structured interviews for M. andongensis and 500 for M. kummel. The relationship between age, sex, and ethnic groups and the species uses was assessed using comparison and correspondence analyses. Nearly all organs of the species were used. Both species were mainly exploited for medicinal purposes but also in construction and as firewood. We found similarities in some uses of the species organs, although the species occur in different ecological zones and are used by different ethnic groups. This result should be considered for the valorization of the species. Most informants reported that populations of M. andongensis were decreasing, although some felt that they were increasing, whereas less than one-third said that M. kummel was decreasing. There were strong relationships between gender, age, and ethnic affiliation of the users and the exploited organs of both species. Potential uses exist based on both the past and current uses of the species and in comparison to other countries where they are exploited. Local ethnoecological knowledge and practices will help to valorize and conserve the species. However, further research on the species’ seed germination and propagation ability are also necessary.
- Full Text:
- Date Issued: 2017
- Authors: Sinasson Gisèle K , Shackleton, Charlie M , Assogbadjo, Achille E , Sinsin, Brice
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181105 , vital:43699 , xlink:href="https://doi.org/10.1007/s12231-017-9370-6"
- Description: Multipurpose NTFP species typically experience higher harvest demand because of their multiple uses, which, when combined with unsustainable land use practices, may threaten population viability. We assessed local knowledge on the uses, habitat, and population status of Mimusops andongensis and Mimusops kummel, both multipurpose NTFP species in Benin, to promote their valorization and conservation and thus sustain local knowledge on their uses for domestication issues. One hundred households were randomly selected for structured interviews for M. andongensis and 500 for M. kummel. The relationship between age, sex, and ethnic groups and the species uses was assessed using comparison and correspondence analyses. Nearly all organs of the species were used. Both species were mainly exploited for medicinal purposes but also in construction and as firewood. We found similarities in some uses of the species organs, although the species occur in different ecological zones and are used by different ethnic groups. This result should be considered for the valorization of the species. Most informants reported that populations of M. andongensis were decreasing, although some felt that they were increasing, whereas less than one-third said that M. kummel was decreasing. There were strong relationships between gender, age, and ethnic affiliation of the users and the exploited organs of both species. Potential uses exist based on both the past and current uses of the species and in comparison to other countries where they are exploited. Local ethnoecological knowledge and practices will help to valorize and conserve the species. However, further research on the species’ seed germination and propagation ability are also necessary.
- Full Text:
- Date Issued: 2017
Local people and conservation officials’ perceptions on relationships and conflicts in South African protected areas
- Thondhlana, Gladman, Cundill, Georgina
- Authors: Thondhlana, Gladman , Cundill, Georgina
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68640 , vital:29300 , https://doi.org/10.1080/21513732.2017.1315742
- Description: Protected areas (PAs) are often conflict-ridden, but conflict resolution mechanisms are often constrained by little appreciation of the perceptions of the principal agents (PA managers and local communities) about such conflicts. Getting local people’s support in PA management efforts is considered important for achieving conservation and livelihood goals. Using data from 13 nature reserves in South Africa, this study explores the perceptions of reserve managers and local communities about their relationships and the existence and underlying causes of conflicts. The findings showed sharp contrasts in perceptions between reserve managers and local communities. Reserve managers generally perceived that there were no conflicts with local communities and that their relationship with them was positive while local communities thought otherwise, claiming conflicts were centred around restricted access to PAs, lack of benefits from PAs and communication problems. These findings have profound implications for conservation, especially considering the importance of getting local people’s support in PA management.
- Full Text:
- Date Issued: 2017
- Authors: Thondhlana, Gladman , Cundill, Georgina
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68640 , vital:29300 , https://doi.org/10.1080/21513732.2017.1315742
- Description: Protected areas (PAs) are often conflict-ridden, but conflict resolution mechanisms are often constrained by little appreciation of the perceptions of the principal agents (PA managers and local communities) about such conflicts. Getting local people’s support in PA management efforts is considered important for achieving conservation and livelihood goals. Using data from 13 nature reserves in South Africa, this study explores the perceptions of reserve managers and local communities about their relationships and the existence and underlying causes of conflicts. The findings showed sharp contrasts in perceptions between reserve managers and local communities. Reserve managers generally perceived that there were no conflicts with local communities and that their relationship with them was positive while local communities thought otherwise, claiming conflicts were centred around restricted access to PAs, lack of benefits from PAs and communication problems. These findings have profound implications for conservation, especially considering the importance of getting local people’s support in PA management.
- Full Text:
- Date Issued: 2017
Local setting influences the quantity of household food waste in mid-sized South African towns
- Chakona, Gamuchirai, Shackleton, Charlie M
- Authors: Chakona, Gamuchirai , Shackleton, Charlie M
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60866 , vital:27847 , https://doi.org/10.1371/journal.pone.0189407
- Description: The world faces a food security challenge with approximately 868 million people undernourished and about two billion people suffering from the negative health consequences of micronutrient deficiencies. Yet, it is believed that at least 33% of food produced for human consumption is lost or wasted along the food chain. As food waste has a negative effect on food security, the present study sought to quantify household food waste along the ruralurban continuum in three South African mid-sized towns situated along an agro-ecological gradient. We quantified the types of foods and drinks that households threw away in the previous 48 hours and identified the causes of household food waste in the three sites. More households wasted prepared food (27%) than unprepared food (15%) and drinks (8%). However, households threw away greater quantities of unprepared food in the 48-hour recall period (268.6±610.1 g, 90% confidence interval: 175.5 to 361.7 g) compared to prepared food (121.0±132.4 g, 90% confidence interval: 100.8 to 141.3 g) and drinks (77.0±192.5 ml, 90% confidence interval: 47.7 to 106.4 ml). The estimated per capita food waste (5±10 kg of unprepared food waste, 3±4 kg of prepared food waste and 1±3 litres of drinks waste per person per year) overlaps with that estimated for other developing countries, but lower than most developed countries. However, the estimated average amount of food waste per person per year for this study (12.35 kg) was higher relative to that estimated for developing countries (8.5 kg per person per year). Household food waste was mainly a result of consumer behavior concerning food preparation and storage. Integrated approaches are required to address this developmental issue affecting South African societies, which include promoting sound food management to decrease household food waste. Also, increased awareness and educational campaigns for household food waste reduction interventions are discussed.
- Full Text:
- Date Issued: 2017
- Authors: Chakona, Gamuchirai , Shackleton, Charlie M
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60866 , vital:27847 , https://doi.org/10.1371/journal.pone.0189407
- Description: The world faces a food security challenge with approximately 868 million people undernourished and about two billion people suffering from the negative health consequences of micronutrient deficiencies. Yet, it is believed that at least 33% of food produced for human consumption is lost or wasted along the food chain. As food waste has a negative effect on food security, the present study sought to quantify household food waste along the ruralurban continuum in three South African mid-sized towns situated along an agro-ecological gradient. We quantified the types of foods and drinks that households threw away in the previous 48 hours and identified the causes of household food waste in the three sites. More households wasted prepared food (27%) than unprepared food (15%) and drinks (8%). However, households threw away greater quantities of unprepared food in the 48-hour recall period (268.6±610.1 g, 90% confidence interval: 175.5 to 361.7 g) compared to prepared food (121.0±132.4 g, 90% confidence interval: 100.8 to 141.3 g) and drinks (77.0±192.5 ml, 90% confidence interval: 47.7 to 106.4 ml). The estimated per capita food waste (5±10 kg of unprepared food waste, 3±4 kg of prepared food waste and 1±3 litres of drinks waste per person per year) overlaps with that estimated for other developing countries, but lower than most developed countries. However, the estimated average amount of food waste per person per year for this study (12.35 kg) was higher relative to that estimated for developing countries (8.5 kg per person per year). Household food waste was mainly a result of consumer behavior concerning food preparation and storage. Integrated approaches are required to address this developmental issue affecting South African societies, which include promoting sound food management to decrease household food waste. Also, increased awareness and educational campaigns for household food waste reduction interventions are discussed.
- Full Text:
- Date Issued: 2017
Looking after freedom?:
- Authors: Dantas, Nancy
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147081 , vital:38591 , https://www.buala.org/en/ill-visit/looking-after-freedom
- Description: Did freedom come to South Africa in 1994? Should it be marked and set in time, or is it a fragile process, an ambition and a becoming? Do we see ourselves coming closer to this ideal, or desperately receding from it as an invisible rip current pulls us away? To think of freedom as a given, a day in the year or a landmark on the horizon is to neglect that liberty from bondage and oppression, in all its disastrous and fatidic forms requires vigilance, nurturing and a spirit of insatiable demand. When our freedom becomes commodified, transformed into a mark on annual calendars, a mere commemoration; something we think have obtained and cannot possibly stand to loose, we are all in for trouble.
- Full Text:
- Date Issued: 2017
- Authors: Dantas, Nancy
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147081 , vital:38591 , https://www.buala.org/en/ill-visit/looking-after-freedom
- Description: Did freedom come to South Africa in 1994? Should it be marked and set in time, or is it a fragile process, an ambition and a becoming? Do we see ourselves coming closer to this ideal, or desperately receding from it as an invisible rip current pulls us away? To think of freedom as a given, a day in the year or a landmark on the horizon is to neglect that liberty from bondage and oppression, in all its disastrous and fatidic forms requires vigilance, nurturing and a spirit of insatiable demand. When our freedom becomes commodified, transformed into a mark on annual calendars, a mere commemoration; something we think have obtained and cannot possibly stand to loose, we are all in for trouble.
- Full Text:
- Date Issued: 2017
Looking underneath: deconstruction in Hogarth's Industry and Idleness
- Authors: Herbst, Michael
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147803 , vital:38674 , https://doi.org/10.1080/00043389.2003.11877010
- Description: In Hogarth's engraved series Industry and Idleness two young men from lower-class backgrounds are apprenticed to Mr West, a weaver. The first plate (1) lays bare the two apprentices' marked difference in temperament: Francis Goodchild works contentedly at his well-lit loom with his 'Prentice's Guide- a standard manual of instruction and advice for London apprentices in various trades - open on the floor below him. In the gloomy foreground Thomas Idle snores crassly at his loom, oblivious of his 'Prentice's Guide, which has apparently been reduced to tatters by the cat that now toys with the abandoned shuttle.
- Full Text:
- Date Issued: 2017
- Authors: Herbst, Michael
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147803 , vital:38674 , https://doi.org/10.1080/00043389.2003.11877010
- Description: In Hogarth's engraved series Industry and Idleness two young men from lower-class backgrounds are apprenticed to Mr West, a weaver. The first plate (1) lays bare the two apprentices' marked difference in temperament: Francis Goodchild works contentedly at his well-lit loom with his 'Prentice's Guide- a standard manual of instruction and advice for London apprentices in various trades - open on the floor below him. In the gloomy foreground Thomas Idle snores crassly at his loom, oblivious of his 'Prentice's Guide, which has apparently been reduced to tatters by the cat that now toys with the abandoned shuttle.
- Full Text:
- Date Issued: 2017
Lost and found: the value of a little known bilingual dictionary towards the intellectualization of Ndau
- Sithole, Emmanuel, Nkomo, Dion
- Authors: Sithole, Emmanuel , Nkomo, Dion
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67537 , vital:29109 , http://dx.doi.org/10.5788/27-1-1411
- Description: Publisher version , This article critically evaluates the ChiNdau–English and English–ChiNdau Vocabulary: With Grammatical Notes, a bilingual dictionary published in 1915 by the American Board Mission (Rhodesian Branch), with a view of determining its suitability for use as a point of departure for modern Ndau lexicography. More than a century after its publication, it remains the only dictionary in the language. The language has been treated as a dialect of Shona for close to a century, until its emergence as one of the country's sixteen officially-recognized languages in the 2013 Constitution of Zimbabwe. This landmark development requires practical work that can transform Ndau into a fully-fledged and intellectualized language. Lexicography is one of the key intellectual enterprises that can contribute in this regard. It is therefore the contention of this article that the existing dictionary be considered as a vital point of reference for future lexicographic work in Ndau. An analysis of various aspects of the dictionary indicate that, notwithstanding some limitations, this dictionary indeed managed to set some standards that may be incorporated in current and future lexicographic works in this less documented language.
- Full Text:
- Date Issued: 2017
- Authors: Sithole, Emmanuel , Nkomo, Dion
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67537 , vital:29109 , http://dx.doi.org/10.5788/27-1-1411
- Description: Publisher version , This article critically evaluates the ChiNdau–English and English–ChiNdau Vocabulary: With Grammatical Notes, a bilingual dictionary published in 1915 by the American Board Mission (Rhodesian Branch), with a view of determining its suitability for use as a point of departure for modern Ndau lexicography. More than a century after its publication, it remains the only dictionary in the language. The language has been treated as a dialect of Shona for close to a century, until its emergence as one of the country's sixteen officially-recognized languages in the 2013 Constitution of Zimbabwe. This landmark development requires practical work that can transform Ndau into a fully-fledged and intellectualized language. Lexicography is one of the key intellectual enterprises that can contribute in this regard. It is therefore the contention of this article that the existing dictionary be considered as a vital point of reference for future lexicographic work in Ndau. An analysis of various aspects of the dictionary indicate that, notwithstanding some limitations, this dictionary indeed managed to set some standards that may be incorporated in current and future lexicographic works in this less documented language.
- Full Text:
- Date Issued: 2017
MD-TASK: a software suite for analyzing molecular dynamics trajectories
- Brown, David K, Penkler, David L, Amamuddy, Olivier S, Ross, Caroline J, Atilgan, Ali R, Atilgan, Canan, Tastan Bishop, Özlem
- Authors: Brown, David K , Penkler, David L , Amamuddy, Olivier S , Ross, Caroline J , Atilgan, Ali R , Atilgan, Canan , Tastan Bishop, Özlem
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125138 , vital:35735 , https://doi.10.1093/bioinformatics/btx349
- Description: Molecular dynamics (MD) determines the physical motions of atoms of a biological macromolecule in a cell-like environment and is an important method in structural bioinformatics. Traditionally, measurements such as root mean square deviation, root mean square fluctuation, radius of gyration, and various energy measures have been used to analyze MD simulations. Here, we present MD-TASK, a novel software suite that employs graph theory techniques, perturbation response scanning, and dynamic cross-correlation to provide unique ways for analyzing MD trajectories.
- Full Text:
- Date Issued: 2017
- Authors: Brown, David K , Penkler, David L , Amamuddy, Olivier S , Ross, Caroline J , Atilgan, Ali R , Atilgan, Canan , Tastan Bishop, Özlem
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125138 , vital:35735 , https://doi.10.1093/bioinformatics/btx349
- Description: Molecular dynamics (MD) determines the physical motions of atoms of a biological macromolecule in a cell-like environment and is an important method in structural bioinformatics. Traditionally, measurements such as root mean square deviation, root mean square fluctuation, radius of gyration, and various energy measures have been used to analyze MD simulations. Here, we present MD-TASK, a novel software suite that employs graph theory techniques, perturbation response scanning, and dynamic cross-correlation to provide unique ways for analyzing MD trajectories.
- Full Text:
- Date Issued: 2017
Minimum dietary diversity scores for women indicate micronutrient adequacy and food insecurity status in South African towns
- Chakona, Gamuchirai, Shackleton, Charlie M
- Authors: Chakona, Gamuchirai , Shackleton, Charlie M
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60930 , vital:27892 , http://dx.doi.org/10.3390/nu9080812
- Description: The lack of dietary diversity is a severe problem experienced by most poor households globally. In particular; women of reproductive age (WRA) are at high risk of inadequate intake of micronutrients resulting from diets dominated by starchy staples. The present study considered the diets, dietary diversity, and food security of women aged 15-49 years along the rural-urban continuum in three South African towns situated along an agro-ecological gradient. A 48 h dietary recall was conducted across two seasons with 554 women from rural, peri-urban, and urban locations of Richards Bay, Dundee, and Harrismith. Minimum Dietary Diversity for WRA (MDD-W) were calculated and a dichotomous indicator based on a set of ten food groups was used to determine if women had consumed at least five food groups the previous 48 h to achieve minimum dietary intake for women. The mean (±sd) MDD-W for Richards Bay (3.78 ± 0.07) was significantly higher than at Dundee (3.21 ± 0.08) and Harrismith (3.36 ± 0.07). Food security and MDD-W were significantly higher in urban locations than in peri-urban or rural ones. There was lower dependence on food purchasing in Richards Bay compared to Dundee and Harrismith. The majority of women in Richards Bay practiced subsistence agriculture, produced a surplus for sale, and collected wild foods which improved dietary intake and food security. The peri-urban populations had limited dietary intake and were more food insecure because of high levels of poverty, unemployment, and lack of land. Peri-urban dwellers are therefore more sensitive to changes in incomes and food prices because they lack safety nets to absorb income or price shocks as they purchase more, rather than growing their own food. This compromises dietary diversity as they have limited access to diverse foods.
- Full Text:
- Date Issued: 2017
- Authors: Chakona, Gamuchirai , Shackleton, Charlie M
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60930 , vital:27892 , http://dx.doi.org/10.3390/nu9080812
- Description: The lack of dietary diversity is a severe problem experienced by most poor households globally. In particular; women of reproductive age (WRA) are at high risk of inadequate intake of micronutrients resulting from diets dominated by starchy staples. The present study considered the diets, dietary diversity, and food security of women aged 15-49 years along the rural-urban continuum in three South African towns situated along an agro-ecological gradient. A 48 h dietary recall was conducted across two seasons with 554 women from rural, peri-urban, and urban locations of Richards Bay, Dundee, and Harrismith. Minimum Dietary Diversity for WRA (MDD-W) were calculated and a dichotomous indicator based on a set of ten food groups was used to determine if women had consumed at least five food groups the previous 48 h to achieve minimum dietary intake for women. The mean (±sd) MDD-W for Richards Bay (3.78 ± 0.07) was significantly higher than at Dundee (3.21 ± 0.08) and Harrismith (3.36 ± 0.07). Food security and MDD-W were significantly higher in urban locations than in peri-urban or rural ones. There was lower dependence on food purchasing in Richards Bay compared to Dundee and Harrismith. The majority of women in Richards Bay practiced subsistence agriculture, produced a surplus for sale, and collected wild foods which improved dietary intake and food security. The peri-urban populations had limited dietary intake and were more food insecure because of high levels of poverty, unemployment, and lack of land. Peri-urban dwellers are therefore more sensitive to changes in incomes and food prices because they lack safety nets to absorb income or price shocks as they purchase more, rather than growing their own food. This compromises dietary diversity as they have limited access to diverse foods.
- Full Text:
- Date Issued: 2017