Photodynamic antimicrobial chemotherapy activity of (5,10,15,20-tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III)
- Managa, Muthumuni, Amuhaya, Edith, Nyokong, Tebello
- Authors: Managa, Muthumuni , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Authors: Managa, Muthumuni , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
Photophysical studies of newly derivatized mono substituted phthalocyanines grafted onto silica nanoparticles via click chemistry
- Fashina, Adedayo, Amuhaya, Edith, Nyokong, Tebello
- Authors: Fashina, Adedayo , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7272 , http://hdl.handle.net/10962/d1020287 , Original publication is available at http://dx.doi.org/10.1016/j.saa.2014.12.070
- Description: This work reports on the synthesis, characterization and photophysical studies of newly derived phthalocyanine complexes and the phthalocyanine–silica nanoparticles conjugates. The derived phthalocyanine complexes have one terminal alkyne group. The derived phthalocyanine complexes showed improved photophysical properties (ФF, ФT, ΦΔ and τT) compared to the respective phthalocyanine complexes from which they were derived. The derived phthalocyanine complexes were conjugated to the surface of an azide functionalized silica nanoparticles via copper (1) catalyzed cyclo-addition reaction. All the conjugates showed lower triplet quantum yields ranging from 0.37 to 0.44 compared to the free phthalocyanine complexes. The triplet lifetimes ranged from 352 to 484 μs for the conjugates and from 341 to 366 μs for the free phthalocyanine complexes.
- Full Text: false
- Authors: Fashina, Adedayo , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7272 , http://hdl.handle.net/10962/d1020287 , Original publication is available at http://dx.doi.org/10.1016/j.saa.2014.12.070
- Description: This work reports on the synthesis, characterization and photophysical studies of newly derived phthalocyanine complexes and the phthalocyanine–silica nanoparticles conjugates. The derived phthalocyanine complexes have one terminal alkyne group. The derived phthalocyanine complexes showed improved photophysical properties (ФF, ФT, ΦΔ and τT) compared to the respective phthalocyanine complexes from which they were derived. The derived phthalocyanine complexes were conjugated to the surface of an azide functionalized silica nanoparticles via copper (1) catalyzed cyclo-addition reaction. All the conjugates showed lower triplet quantum yields ranging from 0.37 to 0.44 compared to the free phthalocyanine complexes. The triplet lifetimes ranged from 352 to 484 μs for the conjugates and from 341 to 366 μs for the free phthalocyanine complexes.
- Full Text: false
Physicochemical and photodynamic antimicrobial chemotherapy studies of mono- and tetra-pyridyloxy substituted indium(III) phthalocyanines
- Osifeko, Olawale L, Durmuş, Mahmut, Nyokong, Tebello
- Authors: Osifeko, Olawale L , Durmuş, Mahmut , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7255 , http://hdl.handle.net/10962/d1020264 , http://dx.doi.org/10.1016/j.jphotochem.2014.12.011
- Description: The synthesis and photophysicochemical properties of mono- and tetra-pyridyloxy substituted indium(III) phthalocyanines (InPcs) are presented in this study. General trends are described for quantum yields of fluorescence, triplet, singlet oxygen and photodegradation as well as lifetimes of fluorescence and triplet state of these compounds. The complexes exhibited high singlet oxygen quantum yields (ФΔ) ranging from 0.44 to 0.66 in DMF, and from 0.44 to 0.69 in DMSO and ФΔ = 0.31 for the quartenized tetra substituted InPc which is soluble in water. The triplet quantum yields (ФT) ranged from 0.77 to 0.95 in DMF and from 0.77 to 0.94) in DMSO. The tetra substituted photosensitizers do not differ in their inactivation of bacteria with over 8 log reduction of viable bacteria when compared with the mono substituted photosensitizer which could only manage a 1 log reduction. , Original publication is available at http://dx.doi.org/10.1016/j.jphotochem.2014.12.011
- Full Text: false
- Authors: Osifeko, Olawale L , Durmuş, Mahmut , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7255 , http://hdl.handle.net/10962/d1020264 , http://dx.doi.org/10.1016/j.jphotochem.2014.12.011
- Description: The synthesis and photophysicochemical properties of mono- and tetra-pyridyloxy substituted indium(III) phthalocyanines (InPcs) are presented in this study. General trends are described for quantum yields of fluorescence, triplet, singlet oxygen and photodegradation as well as lifetimes of fluorescence and triplet state of these compounds. The complexes exhibited high singlet oxygen quantum yields (ФΔ) ranging from 0.44 to 0.66 in DMF, and from 0.44 to 0.69 in DMSO and ФΔ = 0.31 for the quartenized tetra substituted InPc which is soluble in water. The triplet quantum yields (ФT) ranged from 0.77 to 0.95 in DMF and from 0.77 to 0.94) in DMSO. The tetra substituted photosensitizers do not differ in their inactivation of bacteria with over 8 log reduction of viable bacteria when compared with the mono substituted photosensitizer which could only manage a 1 log reduction. , Original publication is available at http://dx.doi.org/10.1016/j.jphotochem.2014.12.011
- Full Text: false
Physicochemical behavior of nanohybrids of mono and tetra substituted carboxyphenoxy phthalocyanine covalently linked to GSH–CdTe/CdS/ZnS quantum dots
- Oluwole, David O, Nyokong, Tebello
- Authors: Oluwole, David O , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7266 , http://hdl.handle.net/10962/d1020275 , http://dx.doi.org/10.1016/j.poly.2014.10.024
- Description: Zinc monocarboxyphenoxy and tetracarboxyphenoxy phthalocyanines were covalently linked with three different sizes of glutathione capped core/shell/shell {CdTe/CdS/ZnS(4.2), CdTe/CdS/ZnS(5.1) and CdTe/CdS/ZnS(6.7)}; a core shell {CdTe/CdS(3.1)} and core {CdTe(2.4)} quantum dots. The physicochemical behavior and Förster resonance energy transfer (FRET) processes of the nanohybrids were investigated. The highest FRET efficiency was observed with CdTe/CdS/ZnS(6.7) nanohybrids with 98% and the least efficiency was observed with CdTe(2.4) nanohybrids with 85%. The CdTe/CdS/ZnS(6.7) also showed the best physicochemical behavior. These good physicochemical properties make the synthesized nanohybrids viable photosensitizers. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.10.024
- Full Text: false
- Authors: Oluwole, David O , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7266 , http://hdl.handle.net/10962/d1020275 , http://dx.doi.org/10.1016/j.poly.2014.10.024
- Description: Zinc monocarboxyphenoxy and tetracarboxyphenoxy phthalocyanines were covalently linked with three different sizes of glutathione capped core/shell/shell {CdTe/CdS/ZnS(4.2), CdTe/CdS/ZnS(5.1) and CdTe/CdS/ZnS(6.7)}; a core shell {CdTe/CdS(3.1)} and core {CdTe(2.4)} quantum dots. The physicochemical behavior and Förster resonance energy transfer (FRET) processes of the nanohybrids were investigated. The highest FRET efficiency was observed with CdTe/CdS/ZnS(6.7) nanohybrids with 98% and the least efficiency was observed with CdTe(2.4) nanohybrids with 85%. The CdTe/CdS/ZnS(6.7) also showed the best physicochemical behavior. These good physicochemical properties make the synthesized nanohybrids viable photosensitizers. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.10.024
- Full Text: false
Public foetal images and the regulation of middle-class pregnancy in the online media : a view from South Africa
- Macleod, Catriona I, Howell, Simon
- Authors: Macleod, Catriona I , Howell, Simon
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6307 , http://hdl.handle.net/10962/d1018803 , http://www.tandfonline.com/doi/full/10.1080/13691058.2015.1046138
- Description: Ultrasonography images and their derivatives have been taken up in a range of ‘public’ spaces, including medical textbooks, the media, anti-abortion material, advertising, the Internet and public health facilities. Feminists have critiqued the personification of the foetus, the bifurcation of the woman’s body and the reduction of the pregnant woman to a disembodied womb. What has received less attention is how these images frequently intersect with race, class, gender and heteronormativity in the creation of idealised and normative understandings of pregnancy. This paper focuses on the discursive positioning of pregnant women as ‘mothers’ and foetuses as ‘babies’ in online media targeted at a South African audience, where race and class continue to intersect in complex ways. We show how the ontologically specific understandings of ‘mummies’ and ‘babies’ emerge through the use of foetal images to construct specific understandings of the ‘ideal’ pregnancy. In the process, pregnant women are made responsible for ensuring that their pregnancy conforms to these ideals, which includes the purchasing of the various goods advertised by the websites. Not only does this point to a commodification of pregnancy, but also serves to reinforce a cultural understanding of White, middle-class pregnancy as constituting the normative ‘correct’ form of pregnancy. , Full text access on publisher website: http://www.tandfonline.com/doi/full/10.1080/13691058.2015.1046138
- Full Text: false
- Authors: Macleod, Catriona I , Howell, Simon
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6307 , http://hdl.handle.net/10962/d1018803 , http://www.tandfonline.com/doi/full/10.1080/13691058.2015.1046138
- Description: Ultrasonography images and their derivatives have been taken up in a range of ‘public’ spaces, including medical textbooks, the media, anti-abortion material, advertising, the Internet and public health facilities. Feminists have critiqued the personification of the foetus, the bifurcation of the woman’s body and the reduction of the pregnant woman to a disembodied womb. What has received less attention is how these images frequently intersect with race, class, gender and heteronormativity in the creation of idealised and normative understandings of pregnancy. This paper focuses on the discursive positioning of pregnant women as ‘mothers’ and foetuses as ‘babies’ in online media targeted at a South African audience, where race and class continue to intersect in complex ways. We show how the ontologically specific understandings of ‘mummies’ and ‘babies’ emerge through the use of foetal images to construct specific understandings of the ‘ideal’ pregnancy. In the process, pregnant women are made responsible for ensuring that their pregnancy conforms to these ideals, which includes the purchasing of the various goods advertised by the websites. Not only does this point to a commodification of pregnancy, but also serves to reinforce a cultural understanding of White, middle-class pregnancy as constituting the normative ‘correct’ form of pregnancy. , Full text access on publisher website: http://www.tandfonline.com/doi/full/10.1080/13691058.2015.1046138
- Full Text: false
Public reproductive health and ‘unintended’ pregnancies: introducing the construct ‘supportability’
- Authors: Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6313 , http://hdl.handle.net/10962/d1019881 , https://academic.oup.com/jpubhealth/article-lookup/doi/10.1093/pubmed/fdv123
- Description: In this Perspectives paper, I outline the limitations of the concept of ‘intentionality’ in public reproductive health understandings of pregnancy. ‘Intentionality’, ‘plannedness’, ‘wantedness’ and ‘timing’ place individual cognitions, psychology and/or behaviors at the center of public health conceptualizations of pregnancies, thereby leaving the underlying social and structural dynamics under-examined. I propose a model that places ‘supportability’ at the center of thinking about pregnancies and that allows for an analysis of the intersection of individual cognitions, emotions and behavior with micro-level interactive spaces and macro-level issues. , Full text access on Publisher website: https://academic.oup.com/jpubhealth/article-lookup/doi/10.1093/pubmed/fdv123
- Full Text: false
- Authors: Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6313 , http://hdl.handle.net/10962/d1019881 , https://academic.oup.com/jpubhealth/article-lookup/doi/10.1093/pubmed/fdv123
- Description: In this Perspectives paper, I outline the limitations of the concept of ‘intentionality’ in public reproductive health understandings of pregnancy. ‘Intentionality’, ‘plannedness’, ‘wantedness’ and ‘timing’ place individual cognitions, psychology and/or behaviors at the center of public health conceptualizations of pregnancies, thereby leaving the underlying social and structural dynamics under-examined. I propose a model that places ‘supportability’ at the center of thinking about pregnancies and that allows for an analysis of the intersection of individual cognitions, emotions and behavior with micro-level interactive spaces and macro-level issues. , Full text access on Publisher website: https://academic.oup.com/jpubhealth/article-lookup/doi/10.1093/pubmed/fdv123
- Full Text: false
Sexual socialisation in Life Orientation manuals versus popular music: responsibilisation versus pleasure, tension and complexity
- Macleod, Catriona I, Moodley, Dale, Saville Young, Lisa
- Authors: Macleod, Catriona I , Moodley, Dale , Saville Young, Lisa
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6309 , http://hdl.handle.net/10962/d1018866
- Description: This paper compares two forms of sexual socialisation to which learners are exposed: the sexuality education components of the Life Orientation (LO) manuals and the lyrical content and videos of popular songs. We performed a textual analysis of the sexual subject positions made available in, first, the LO manuals used in Grade 10 classes and, second, the two songs voted most popular by the Grade 10 learners of two diverse schools in the Eastern Cape. Of interest in this paper is whether and how these two forms of sexual socialisation – one representing state-sanctioned sexual socialisation and the other learners’ chosen cultural expression that represents informal sexual socialisation – dovetail or diverge. Against a backdrop of heterosexuality and an assumption of the ‘adolescent-in-transition’ discourse, the main sexual subject positions featured in the LO manuals are the responsible sexual subject and the sexual victim. A number of sexualised subject positions are portrayed in the songs, with these subject positions depicting sex as a site of pleasure, tension and complexity. Although these two modes of sexual socialisation use different genres of communication, we argue that learners’ choice of songs that depict fluid sexual subject positions can help to inform LO sexuality education in ways that takes learners’ preferred cultural expression seriously and that moves away from the imperative of responsibilisation.
- Full Text:
- Authors: Macleod, Catriona I , Moodley, Dale , Saville Young, Lisa
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6309 , http://hdl.handle.net/10962/d1018866
- Description: This paper compares two forms of sexual socialisation to which learners are exposed: the sexuality education components of the Life Orientation (LO) manuals and the lyrical content and videos of popular songs. We performed a textual analysis of the sexual subject positions made available in, first, the LO manuals used in Grade 10 classes and, second, the two songs voted most popular by the Grade 10 learners of two diverse schools in the Eastern Cape. Of interest in this paper is whether and how these two forms of sexual socialisation – one representing state-sanctioned sexual socialisation and the other learners’ chosen cultural expression that represents informal sexual socialisation – dovetail or diverge. Against a backdrop of heterosexuality and an assumption of the ‘adolescent-in-transition’ discourse, the main sexual subject positions featured in the LO manuals are the responsible sexual subject and the sexual victim. A number of sexualised subject positions are portrayed in the songs, with these subject positions depicting sex as a site of pleasure, tension and complexity. Although these two modes of sexual socialisation use different genres of communication, we argue that learners’ choice of songs that depict fluid sexual subject positions can help to inform LO sexuality education in ways that takes learners’ preferred cultural expression seriously and that moves away from the imperative of responsibilisation.
- Full Text:
South African crime fiction: sleuthing the State post-1994, African Identities
- Authors: Naidu, Samantha
- Date: 2015
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10962/53912 , vital:26357 , http://dx.doi.org/10.1080/14725843.2015.1009621 , https://orcid.org/0000-0001-9456-8657
- Description: In this essay we demonstrate how the burgeoning field of South African crime fiction has responded to the birth and development of a democratic, post-apartheid South African state. First, an overview of South African crime fiction in the last 20 years is presented. Then the essay presents an argument for South African crime fiction to be regarded as the ‘new political novel’, based on its capacity for socio-political analysis. We use Deon Meyer, arguably South Africa’s most popular and successful crime fiction author, as an exemplar for our argument. In the following section, the genresnob debate and the resurgence of such terms as ‘lowbrow’ and ‘highbrow’ are considered in relation to crime fiction and the role it plays in the socio-cultural arena of post-apartheid South Africa. We conclude with a comment on the significance of popular literary genres for democracy and critical discourses which underpin that democracy. The essay shows that crime fiction is a strong tool for socio-political analysis in a democratic South Africa, because it promotes critical discourse in society, despite being deemed lowbrow or ideologically ambiguous.
- Full Text: false
- Authors: Naidu, Samantha
- Date: 2015
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10962/53912 , vital:26357 , http://dx.doi.org/10.1080/14725843.2015.1009621 , https://orcid.org/0000-0001-9456-8657
- Description: In this essay we demonstrate how the burgeoning field of South African crime fiction has responded to the birth and development of a democratic, post-apartheid South African state. First, an overview of South African crime fiction in the last 20 years is presented. Then the essay presents an argument for South African crime fiction to be regarded as the ‘new political novel’, based on its capacity for socio-political analysis. We use Deon Meyer, arguably South Africa’s most popular and successful crime fiction author, as an exemplar for our argument. In the following section, the genresnob debate and the resurgence of such terms as ‘lowbrow’ and ‘highbrow’ are considered in relation to crime fiction and the role it plays in the socio-cultural arena of post-apartheid South Africa. We conclude with a comment on the significance of popular literary genres for democracy and critical discourses which underpin that democracy. The essay shows that crime fiction is a strong tool for socio-political analysis in a democratic South Africa, because it promotes critical discourse in society, despite being deemed lowbrow or ideologically ambiguous.
- Full Text: false
Stigma resistance in online child free communities : the limitations of choice rhetoric
- Morison, Tracy, Macleod, Catriona I, Lynch, Ingrid, Mijas, Magda, Shivakumar, Seemanthini T
- Authors: Morison, Tracy , Macleod, Catriona I , Lynch, Ingrid , Mijas, Magda , Shivakumar, Seemanthini T
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6311 , http://hdl.handle.net/10962/d1019799 , http://journals.sagepub.com/doi/10.1177/0361684315603657
- Description: People who are voluntarily childless, or ‘‘childfree,’’ face considerable stigma. Researchers have begun to explore how these individuals respond to stigma, usually focusing on interpersonal stigma management strategies. We explored participants’ responses to stigma in a way that is cognisant of broader social norms and gender power relations. Using a feminist discursive psychology framework, we analysed women’s and men’s computer-assisted communication about their childfree status. Our analysis draws attention to ‘‘identity work’’ in the context of stigma. We show how the strategic use of ‘‘choice’’ rhetoric allowed participants to avoid stigmatised identities and was used in two contradictory ways. On the one hand, participants drew on a ‘‘childfree-by-choice script,’’ which enabled them to hold a positive identity of themselves as autonomous, rational, and responsible decision makers. On the other hand, they mobilised a ‘‘disavowal of choice script’’ that allowed a person who is unable to choose childlessness (for various reasons) to hold a blameless identity regarding deviation from the norm of parenthood. We demonstrate how choice rhetoric allowed participants to resist stigma and challenge pronatalism to some extent; we discuss the political potential of these scripts for reproductive freedom.
- Full Text:
- Authors: Morison, Tracy , Macleod, Catriona I , Lynch, Ingrid , Mijas, Magda , Shivakumar, Seemanthini T
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6311 , http://hdl.handle.net/10962/d1019799 , http://journals.sagepub.com/doi/10.1177/0361684315603657
- Description: People who are voluntarily childless, or ‘‘childfree,’’ face considerable stigma. Researchers have begun to explore how these individuals respond to stigma, usually focusing on interpersonal stigma management strategies. We explored participants’ responses to stigma in a way that is cognisant of broader social norms and gender power relations. Using a feminist discursive psychology framework, we analysed women’s and men’s computer-assisted communication about their childfree status. Our analysis draws attention to ‘‘identity work’’ in the context of stigma. We show how the strategic use of ‘‘choice’’ rhetoric allowed participants to avoid stigmatised identities and was used in two contradictory ways. On the one hand, participants drew on a ‘‘childfree-by-choice script,’’ which enabled them to hold a positive identity of themselves as autonomous, rational, and responsible decision makers. On the other hand, they mobilised a ‘‘disavowal of choice script’’ that allowed a person who is unable to choose childlessness (for various reasons) to hold a blameless identity regarding deviation from the norm of parenthood. We demonstrate how choice rhetoric allowed participants to resist stigma and challenge pronatalism to some extent; we discuss the political potential of these scripts for reproductive freedom.
- Full Text:
Structural and optical properties of alloyed quaternary CdSeTeS core and CdSeTeS/ZnS core–shell quantum dots
- Adegoke, Oluwasesan, Nyokong, Tebello, Forbes, Patricia B C
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7244 , http://hdl.handle.net/10962/d1020248
- Description: Synthesis of fluorescent alloyed quantum dots (QDs) with unique optical properties suitable for a wide array of chemical, physical and biological applications is of research interest. In this work, highly luminescent and photostable alloyed quaternary CdSeTeS core QDs of two different sizes were fabricated via the organometallic hot-injection synthetic route. Characterization of the nanocrystals were performed using TEM, XRD, UV/vis and fluorescence spectrophotometric techniques. We have demonstrated in this work that the well fabricated alloyed quaternary CdSeTeS core QDs possess unique optical properties that are advantageous over conventional core/shell systems. Formation of the CdSeTeS/ZnS core/shell with the desired optical properties comes with a number of challenges, hence the advantages of the quaternary alloyed core over the core/shell QDs are (i) avoidance of the challenging process of determining the proper shell thickness which can provide the desired optical properties in the core/shell system and (ii) avoidance of the lattice-induced mismatch between the core and the shell material which can either lead to incomplete exciton confinement or dislocation at the core/shell interface. , Original publication is available at http://dx.doi.org/10.1016/j.jallcom.2015.05.083
- Full Text: false
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7244 , http://hdl.handle.net/10962/d1020248
- Description: Synthesis of fluorescent alloyed quantum dots (QDs) with unique optical properties suitable for a wide array of chemical, physical and biological applications is of research interest. In this work, highly luminescent and photostable alloyed quaternary CdSeTeS core QDs of two different sizes were fabricated via the organometallic hot-injection synthetic route. Characterization of the nanocrystals were performed using TEM, XRD, UV/vis and fluorescence spectrophotometric techniques. We have demonstrated in this work that the well fabricated alloyed quaternary CdSeTeS core QDs possess unique optical properties that are advantageous over conventional core/shell systems. Formation of the CdSeTeS/ZnS core/shell with the desired optical properties comes with a number of challenges, hence the advantages of the quaternary alloyed core over the core/shell QDs are (i) avoidance of the challenging process of determining the proper shell thickness which can provide the desired optical properties in the core/shell system and (ii) avoidance of the lattice-induced mismatch between the core and the shell material which can either lead to incomplete exciton confinement or dislocation at the core/shell interface. , Original publication is available at http://dx.doi.org/10.1016/j.jallcom.2015.05.083
- Full Text: false
The development of Palladium(II)-specific amine-functionalized silica-based microparticles : adsorption and column separation studies
- Fayemi, Omolola E, Ogunlaja, Adeniyi S, Antunes, Edith M, Nyokong, Tebello, Tshentu, Zenixole R
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7270 , http://hdl.handle.net/10962/d1020285
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7270 , http://hdl.handle.net/10962/d1020285
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
The Development of Palladium(II)-Specific Amine-Functionalized Silica-Based Microparticles: Adsorption and Column Separation Studies
- Fayemi, Omolola E, Ogunlaja, Adeniyi S, Antunes, Edith M, Nyokong, Tebello, Tshentu, Zenixole R
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7269 , http://hdl.handle.net/10962/d1020278
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7269 , http://hdl.handle.net/10962/d1020278
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
The first world’s third world expert: self-exoticization in Khaled Hosseini's The Kite Runner
- Authors: Naidu, Samantha
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:26358 , http://hdl.handle.net/10962/53922 , http://jcpcsonline.com/contents/ns-v03n1.html , https://orcid.org/0000-0001-9456-8657
- Description: A literary criticism of the book "The Kite Runner" by Khaled Hosseini is presented. It outlines the characters and explores the symbolic significance of these characters. It explores the aspects of contemporary literature among neo-Orientalist representations of the Middle East and the Muslim world. It notes on the contribution of the Euro-American intervention in military and cultural identities of Middle East Orientalists. An overview of the story is also given.
- Full Text: false
- Authors: Naidu, Samantha
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:26358 , http://hdl.handle.net/10962/53922 , http://jcpcsonline.com/contents/ns-v03n1.html , https://orcid.org/0000-0001-9456-8657
- Description: A literary criticism of the book "The Kite Runner" by Khaled Hosseini is presented. It outlines the characters and explores the symbolic significance of these characters. It explores the aspects of contemporary literature among neo-Orientalist representations of the Middle East and the Muslim world. It notes on the contribution of the Euro-American intervention in military and cultural identities of Middle East Orientalists. An overview of the story is also given.
- Full Text: false
The law of divorce and dissolution of life partnerships in South Africa: book review
- Authors: Kruuse, Helen
- Date: 2015
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54129 , vital:26394 , http://scholar.ufs.ac.za:8080/xmlui/handle/11660/2454
- Description: Jackie Heaton’s latest contribution to the family law domain is formidable – 777 pages of carefully crafted opinions and discussions of the law affecting divorce and dissolution of life partnerships. Given the range, diversity and depth of issues in this area, it is no wonder that she calls on those being among the best in their field to assist her in writing up the book.
- Full Text:
- Authors: Kruuse, Helen
- Date: 2015
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54129 , vital:26394 , http://scholar.ufs.ac.za:8080/xmlui/handle/11660/2454
- Description: Jackie Heaton’s latest contribution to the family law domain is formidable – 777 pages of carefully crafted opinions and discussions of the law affecting divorce and dissolution of life partnerships. Given the range, diversity and depth of issues in this area, it is no wonder that she calls on those being among the best in their field to assist her in writing up the book.
- Full Text:
The relationship between concurrently measured SASS (South African Scoring System) and turbidity data archived in the South African River Health Programme’s Rivers Database
- Gordon, Andrew K, Griffin, Neil J, Palmer, Carolyn G
- Authors: Gordon, Andrew K , Griffin, Neil J , Palmer, Carolyn G
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7098 , http://hdl.handle.net/10962/d1015956
- Description: The need for monitoring the biological impacts of instream sediments has long been recognised, yet robust and scientifically defensible tools for doing so are still in the early stages of development because of the difficulties experienced by researchers in characterising the complicated mechanisms of biological effect elicited by sediment particles. Biological monitoring is one such tool, and this paper reports on the initial stages of a study to determine the most applicable approach for measuring the effects of instream sediments on aquatic macroinvertebrates in the South African context. In this first instance, the suitability of the rapid macroinvertebrate biomonitoring tool (the South African Scoring System) was investigated by determining the extent of the correlation between concurrently measured SASS metrics and turbidity data collected for the South African River Health Programme. All three SASS metrics – SASS score, number of taxa (NOT), and average score per taxon (ASPT) – were found to be significantly negatively correlated with turbidity, although variation in the data was high. Turbidity was found to be the major driver of change in ASPT. In contrast, electrical conductivity was the major driver of SASS scores and NOT, with turbidity a close second. When combined, electrical conductivity and turbidity accounted for 80 percent (SASS score) and 75 percent (NOT) of the variation in the regression model. Consequently, SASS metrics are a crude, but reliable, indicator of the negative biological implications of excessive instream sedimentation as measured by turbidity. A number of other potential biomonitoring approaches for detecting the impacts of fine sediment exposure are identified for further investigation: spatial analyses of macroinvertebrate assemblages; and the use of structural and functional metrics.
- Full Text:
- Authors: Gordon, Andrew K , Griffin, Neil J , Palmer, Carolyn G
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7098 , http://hdl.handle.net/10962/d1015956
- Description: The need for monitoring the biological impacts of instream sediments has long been recognised, yet robust and scientifically defensible tools for doing so are still in the early stages of development because of the difficulties experienced by researchers in characterising the complicated mechanisms of biological effect elicited by sediment particles. Biological monitoring is one such tool, and this paper reports on the initial stages of a study to determine the most applicable approach for measuring the effects of instream sediments on aquatic macroinvertebrates in the South African context. In this first instance, the suitability of the rapid macroinvertebrate biomonitoring tool (the South African Scoring System) was investigated by determining the extent of the correlation between concurrently measured SASS metrics and turbidity data collected for the South African River Health Programme. All three SASS metrics – SASS score, number of taxa (NOT), and average score per taxon (ASPT) – were found to be significantly negatively correlated with turbidity, although variation in the data was high. Turbidity was found to be the major driver of change in ASPT. In contrast, electrical conductivity was the major driver of SASS scores and NOT, with turbidity a close second. When combined, electrical conductivity and turbidity accounted for 80 percent (SASS score) and 75 percent (NOT) of the variation in the regression model. Consequently, SASS metrics are a crude, but reliable, indicator of the negative biological implications of excessive instream sedimentation as measured by turbidity. A number of other potential biomonitoring approaches for detecting the impacts of fine sediment exposure are identified for further investigation: spatial analyses of macroinvertebrate assemblages; and the use of structural and functional metrics.
- Full Text:
Visible light transformation of Rhodamine 6G using tetracarbazole zinc phthalocyanine when embedded in electrospun fibers and in the presence of ZnO and Ag particles
- Khoza, Phindile, Nyokong, Tebello
- Authors: Khoza, Phindile , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7246 , http://hdl.handle.net/10962/d1020251
- Description: Herein, we report the photocatalytic transformation of Rhodamine 6G (Rh 6G) using tetracarbazole zinc phthalocyanine (TCbZnPc) when alone or when conjugated with ZnO macroparticles (ZnOMPs) and silver nanoparticles (AgNPs), represented as TCbZnPc–ZnOMPs and TCbZnPc–AgNPs, respectively. The photocatalysts were supported onto electrospun polystyrene fibers. The efficiency of TCbZnPc was improved by the presence of both ZnOMPs and AgNPs. HPLC equipped with UV–vis was used to study phototransformation products. The mechanism of transformation was via the N-de-ethylation of Rh 6G. , Original publication is available at http://dx.doi.org/10.1080/00958972.2015.1013944
- Full Text: false
- Authors: Khoza, Phindile , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7246 , http://hdl.handle.net/10962/d1020251
- Description: Herein, we report the photocatalytic transformation of Rhodamine 6G (Rh 6G) using tetracarbazole zinc phthalocyanine (TCbZnPc) when alone or when conjugated with ZnO macroparticles (ZnOMPs) and silver nanoparticles (AgNPs), represented as TCbZnPc–ZnOMPs and TCbZnPc–AgNPs, respectively. The photocatalysts were supported onto electrospun polystyrene fibers. The efficiency of TCbZnPc was improved by the presence of both ZnOMPs and AgNPs. HPLC equipped with UV–vis was used to study phototransformation products. The mechanism of transformation was via the N-de-ethylation of Rh 6G. , Original publication is available at http://dx.doi.org/10.1080/00958972.2015.1013944
- Full Text: false
When is it legitimate to use images in moral arguments? The use of foetal imagery in anti-abortion campaigns as an exemplar of an illegitimate instance of a legitimate practice
- Kelland, Lindsay, Macleod, Catriona I
- Authors: Kelland, Lindsay , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6305 , http://hdl.handle.net/10962/d1016146
- Description: We aim to interrogate when the use of images in moral persuasion is legitimate. First, we put forward a number of accounts which purport to show that we can use tools other than logical argumentation to convince others, that such tools evoke affective responses and that these responses have authority in the moral domain. Second, we turn to Sarah McGrath’s account, which focuses on the use of imagery as a means to morally persuade. McGrath discusses 4 objections to the use of imagery, and outlines responses that may be used to legitimate the use of imagery in moral arguments. Assuming that we accept her account and that the invocation of affect has authority in the moral domain, we, using McGrath’s responses, examine whether the use of foetal imagery in anti-abortion campaigns is a legitimate instance of this practice.
- Full Text:
- Authors: Kelland, Lindsay , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6305 , http://hdl.handle.net/10962/d1016146
- Description: We aim to interrogate when the use of images in moral persuasion is legitimate. First, we put forward a number of accounts which purport to show that we can use tools other than logical argumentation to convince others, that such tools evoke affective responses and that these responses have authority in the moral domain. Second, we turn to Sarah McGrath’s account, which focuses on the use of imagery as a means to morally persuade. McGrath discusses 4 objections to the use of imagery, and outlines responses that may be used to legitimate the use of imagery in moral arguments. Assuming that we accept her account and that the invocation of affect has authority in the moral domain, we, using McGrath’s responses, examine whether the use of foetal imagery in anti-abortion campaigns is a legitimate instance of this practice.
- Full Text:
‘… a huge monster that should be feared and not done’: lessons learned in sexuality education classes in South Africa
- Shefer, Tamara, Kruger, Lou-Marie, Macleod, Catriona I, Baxen, Jean, Vincent, Louise
- Authors: Shefer, Tamara , Kruger, Lou-Marie , Macleod, Catriona I , Baxen, Jean , Vincent, Louise
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6314 , http://hdl.handle.net/10962/d1020933 , http://www.mrc.ac.za/crime/aspj/2015/AhugeMonster.pdf
- Description: Research has foregrounded the way in which heterosexual practices for many young people are not infrequently bound up with violence and unequal transactional power relations. The Life Orientation sexuality education curriculum in South African schools has been viewed as a potentially valuable space to work with young people on issues of reproductive health, gender and sexual norms and relations. Yet, research has illustrated that such work may not only be failing to impact on more equitable sexual practices between young men and women, but may also serve to reproduce the very discourses and practices that the work aims to challenge. Cultures of violence in youth sexuality are closely connected to prevailing gender norms and practices which, for example, render women as passive victims who are incapable of exercising sexual agency and men as inherently sexually predatory. This paper analyses the talk of Grade 10 learners in nine diverse schools in two South African provinces, the Eastern Cape and the Western Cape, to highlight what ‘lessons’ these young people seem to be learning about sexuality in Life Orientation classes. We find that these lessons foreground cautionary, negative and punitive messages, which reinforce, rather than challenge, normative gender roles. ‘Scare’ messages of danger, damage and disease give rise to presumptions of gendered responsibility for risk and the requirement of female restraint in the face of the assertion of masculine desire and predation. We conclude that the role which sexuality education could play in enabling young women in particular to more successfully negotiate their sexual relationships to serve their own needs, reproductive health and safety, is undermined by regulatory messages directed at controlling young people, and young women in particular – and that instead, young people’s sexual agency has to be acknowledged in any processes of change aimed at gender equality, anti-violence, health and well-being.
- Full Text:
- Authors: Shefer, Tamara , Kruger, Lou-Marie , Macleod, Catriona I , Baxen, Jean , Vincent, Louise
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6314 , http://hdl.handle.net/10962/d1020933 , http://www.mrc.ac.za/crime/aspj/2015/AhugeMonster.pdf
- Description: Research has foregrounded the way in which heterosexual practices for many young people are not infrequently bound up with violence and unequal transactional power relations. The Life Orientation sexuality education curriculum in South African schools has been viewed as a potentially valuable space to work with young people on issues of reproductive health, gender and sexual norms and relations. Yet, research has illustrated that such work may not only be failing to impact on more equitable sexual practices between young men and women, but may also serve to reproduce the very discourses and practices that the work aims to challenge. Cultures of violence in youth sexuality are closely connected to prevailing gender norms and practices which, for example, render women as passive victims who are incapable of exercising sexual agency and men as inherently sexually predatory. This paper analyses the talk of Grade 10 learners in nine diverse schools in two South African provinces, the Eastern Cape and the Western Cape, to highlight what ‘lessons’ these young people seem to be learning about sexuality in Life Orientation classes. We find that these lessons foreground cautionary, negative and punitive messages, which reinforce, rather than challenge, normative gender roles. ‘Scare’ messages of danger, damage and disease give rise to presumptions of gendered responsibility for risk and the requirement of female restraint in the face of the assertion of masculine desire and predation. We conclude that the role which sexuality education could play in enabling young women in particular to more successfully negotiate their sexual relationships to serve their own needs, reproductive health and safety, is undermined by regulatory messages directed at controlling young people, and young women in particular – and that instead, young people’s sexual agency has to be acknowledged in any processes of change aimed at gender equality, anti-violence, health and well-being.
- Full Text:
“Peer pressure” and “Peer normalization” : discursive resources that justify gendered youth sexualities
- Macleod, Catriona I, Jearey-Graham, Nicola
- Authors: Macleod, Catriona I , Jearey-Graham, Nicola
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6312 , http://hdl.handle.net/10962/d1019877 , https://link.springer.com/article/10.1007/s13178-015-0207-8
- Description: “Peer pressure” is associated in the scientific literature with a range of risky sexual behaviors and with undermining public sexual health messages. Interventions are instituted encouraging young people to resist peer pressure or to model positive peer norms. Taking a discursive psychology perspective, we show how young people themselves use the discourses of “peer pressure to have sex” and “peer normalization of sex” to explain and justify youth sexual activity. Using data from focus group discussions about youth sexualities with students at a South African further education and training college, we show how participants outlined a need for young people to be socially recognizable through engaging in, and talking about, sex and how they implicated peer norms in governing individual sexual behavior. Both discourses pointed to a gendering of peer-endorsed sexual norms: masculine virility, the avoidance of shameful virgin or gay positions, and multiple sexual partners were emphasized for men, while the necessity of keeping a boyfriend and avoiding a “slut” position were foregrounded for women. These discourses potentially undermine the aims of public sexual health programs targeting youth. Nuanced engagement with peer group narratives, especially how sexual activity is explained and justified in a gendered fashion, is indicated. , Full text access on Publisher website: https://link.springer.com/article/10.1007/s13178-015-0207-8
- Full Text: false
- Authors: Macleod, Catriona I , Jearey-Graham, Nicola
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6312 , http://hdl.handle.net/10962/d1019877 , https://link.springer.com/article/10.1007/s13178-015-0207-8
- Description: “Peer pressure” is associated in the scientific literature with a range of risky sexual behaviors and with undermining public sexual health messages. Interventions are instituted encouraging young people to resist peer pressure or to model positive peer norms. Taking a discursive psychology perspective, we show how young people themselves use the discourses of “peer pressure to have sex” and “peer normalization of sex” to explain and justify youth sexual activity. Using data from focus group discussions about youth sexualities with students at a South African further education and training college, we show how participants outlined a need for young people to be socially recognizable through engaging in, and talking about, sex and how they implicated peer norms in governing individual sexual behavior. Both discourses pointed to a gendering of peer-endorsed sexual norms: masculine virility, the avoidance of shameful virgin or gay positions, and multiple sexual partners were emphasized for men, while the necessity of keeping a boyfriend and avoiding a “slut” position were foregrounded for women. These discourses potentially undermine the aims of public sexual health programs targeting youth. Nuanced engagement with peer group narratives, especially how sexual activity is explained and justified in a gendered fashion, is indicated. , Full text access on Publisher website: https://link.springer.com/article/10.1007/s13178-015-0207-8
- Full Text: false
Spatial variation in the macrobenthic assemblages of intertidal seagrass along the long axis of an estuary
- Barnes, R S K, Ellwood, M D F
- Authors: Barnes, R S K , Ellwood, M D F
- Date: 2014-05-29
- Language: English
- Type: Article
- Identifier: vital:6870 , http://hdl.handle.net/10962/d1011513
- Description: Invertebrate macrofaunal biodiversity within intertidal seagrass meadows was investigated over a salinity gradient of <5–35 in the Knysna estuarine system (Garden Route National Park, South Africa). Rather than the classic gradual decline in species richness with distance from the mouth there were zones of considerable faunal stability separated by relatively sharp discontinuities. At the point upstream at which salinity regularly falls below 30, the rich, diverse and highly spatially variable downstream faunal assemblage changed to a less rich, less diverse and more uniform one that dominated the upstream stretch without any further upstream reduction in richness. Nevertheless, without loss of overall richness, assemblage composition changed, again rapidly, in the upper region of the upstream stretch to a zone dominated by the microgastropod Hydrobia, which otherwise occurs in the Knysna system only in highly sheltered regions of the downstream stretch where it is also dominant. The upstream faunal assemblage was a subset of that in the marine-influenced downstream region not a different replacing one. Position along the estuarine gradient accounted for 29% of total assemblage variation. Overall faunal abundance declined with distance upstream until the Hydrobia zone where it rose sharply, but there was no evidence of increase in density of those species remaining on putative release from competition.
- Full Text:
- Authors: Barnes, R S K , Ellwood, M D F
- Date: 2014-05-29
- Language: English
- Type: Article
- Identifier: vital:6870 , http://hdl.handle.net/10962/d1011513
- Description: Invertebrate macrofaunal biodiversity within intertidal seagrass meadows was investigated over a salinity gradient of <5–35 in the Knysna estuarine system (Garden Route National Park, South Africa). Rather than the classic gradual decline in species richness with distance from the mouth there were zones of considerable faunal stability separated by relatively sharp discontinuities. At the point upstream at which salinity regularly falls below 30, the rich, diverse and highly spatially variable downstream faunal assemblage changed to a less rich, less diverse and more uniform one that dominated the upstream stretch without any further upstream reduction in richness. Nevertheless, without loss of overall richness, assemblage composition changed, again rapidly, in the upper region of the upstream stretch to a zone dominated by the microgastropod Hydrobia, which otherwise occurs in the Knysna system only in highly sheltered regions of the downstream stretch where it is also dominant. The upstream faunal assemblage was a subset of that in the marine-influenced downstream region not a different replacing one. Position along the estuarine gradient accounted for 29% of total assemblage variation. Overall faunal abundance declined with distance upstream until the Hydrobia zone where it rose sharply, but there was no evidence of increase in density of those species remaining on putative release from competition.
- Full Text: