Expansive learning in the leadership development of school learners
- Grant, Carolyn, Kajee, Farhana Amod
- Authors: Grant, Carolyn , Kajee, Farhana Amod
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281072 , vital:55689 , xlink:href="https://doi.org/10.1080/13603124.2020.1836405"
- Description: In many countries across the globe, and on the African continent in particular, young people do not have a voice in matters concerning their schooling. By virtue of their minor status, opportunities for participatory decision-making and leadership in schools are restricted, despite national policies to the contrary. This is all-too-often because leadership is (mis)understood as an adult phenomenon. In this article, we present a formative intervention, ‘Learners Lead’, which aimed at developing learner voice and leadership in learners through collective involvement in school change projects. Formulated as a documentary case study, data were generated from 95 research reports, the written assessments of the students registered for the Educational Leadership and Management elective within a postgraduate qualification in a South African university. Analysis drew on the pyramid of learner voice and the theory of expansive learning to examine if, and how, leadership development in learners occurred. The study found that expansive learning’s seven learning actions provided the necessary additional theoretical tools for understanding and unpacking the stages of leadership development as the school change projects unfolded. Implications for practice and research are discussed.
- Full Text:
- Date Issued: 2020
- Authors: Grant, Carolyn , Kajee, Farhana Amod
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281072 , vital:55689 , xlink:href="https://doi.org/10.1080/13603124.2020.1836405"
- Description: In many countries across the globe, and on the African continent in particular, young people do not have a voice in matters concerning their schooling. By virtue of their minor status, opportunities for participatory decision-making and leadership in schools are restricted, despite national policies to the contrary. This is all-too-often because leadership is (mis)understood as an adult phenomenon. In this article, we present a formative intervention, ‘Learners Lead’, which aimed at developing learner voice and leadership in learners through collective involvement in school change projects. Formulated as a documentary case study, data were generated from 95 research reports, the written assessments of the students registered for the Educational Leadership and Management elective within a postgraduate qualification in a South African university. Analysis drew on the pyramid of learner voice and the theory of expansive learning to examine if, and how, leadership development in learners occurred. The study found that expansive learning’s seven learning actions provided the necessary additional theoretical tools for understanding and unpacking the stages of leadership development as the school change projects unfolded. Implications for practice and research are discussed.
- Full Text:
- Date Issued: 2020
Exploring how a genetic attribution to disease relates to stigma experiences of Xhosa patients with schizophrenia in South Africa
- Matshabane, Olivia P, Campbell, Megan, Faure, Marlyn C, Marshall, Patricia A, Mayosi, Bongani M, Stein, Dan J, Appelbaum, Paul S, de Vries, Jantina
- Authors: Matshabane, Olivia P , Campbell, Megan , Faure, Marlyn C , Marshall, Patricia A , Mayosi, Bongani M , Stein, Dan J , Appelbaum, Paul S , de Vries, Jantina
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302487 , vital:58201 , xlink:href="https://doi.org/10.1007/s00127-020-01875-z"
- Description: Background: Over the past three decades, a range of international stakeholders have highlighted the possibility that genomic research may impact stigma associated with psychiatric disorders. Limited research has been conducted in Africa to investigate this relation. Method In the present study, using focus group discussions, we explored the relation between genetic attribution and stigma among 36 Xhosa people with schizophrenia. We addressed three main questions: (1) What causal beliefs do Xhosa people with schizophrenia use to explain their illness and to what extent do genetic explanations play a role in these beliefs? (2) What are the internalised stigma experiences of Xhosa people with schizophrenia? (3) How do genetic explanations relate to stigma experiences, if at all? Results Most participants were able to define genetics and some linked genetics to disease causation. Despite adequate knowledge of genetics and an emphasis on genetic explanations of schizophrenia in the study, most participants held a multitude of causal explanations including: psychosocial, environmental, and cultural. Moreover, participants rarely mentioned disease cause when describing their stigma experiences. Discussion For this population group, there was no straight-forward relation between a genetic attribution and stigma. Therefore, we did not fnd evidence that genetic attribution may signifcantly increase stigma. Although North American and European literature provides conficting evidence regarding this relation, there is increased consensus that biomedical explanations for psychiatric disorders may reduce blame. This study found evidence supporting that consensus. This study provides an empirical foundation to inform ongoing work on the psychosocial implications of psychiatric genomics research in non-Western contexts.
- Full Text:
- Date Issued: 2020
- Authors: Matshabane, Olivia P , Campbell, Megan , Faure, Marlyn C , Marshall, Patricia A , Mayosi, Bongani M , Stein, Dan J , Appelbaum, Paul S , de Vries, Jantina
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302487 , vital:58201 , xlink:href="https://doi.org/10.1007/s00127-020-01875-z"
- Description: Background: Over the past three decades, a range of international stakeholders have highlighted the possibility that genomic research may impact stigma associated with psychiatric disorders. Limited research has been conducted in Africa to investigate this relation. Method In the present study, using focus group discussions, we explored the relation between genetic attribution and stigma among 36 Xhosa people with schizophrenia. We addressed three main questions: (1) What causal beliefs do Xhosa people with schizophrenia use to explain their illness and to what extent do genetic explanations play a role in these beliefs? (2) What are the internalised stigma experiences of Xhosa people with schizophrenia? (3) How do genetic explanations relate to stigma experiences, if at all? Results Most participants were able to define genetics and some linked genetics to disease causation. Despite adequate knowledge of genetics and an emphasis on genetic explanations of schizophrenia in the study, most participants held a multitude of causal explanations including: psychosocial, environmental, and cultural. Moreover, participants rarely mentioned disease cause when describing their stigma experiences. Discussion For this population group, there was no straight-forward relation between a genetic attribution and stigma. Therefore, we did not fnd evidence that genetic attribution may signifcantly increase stigma. Although North American and European literature provides conficting evidence regarding this relation, there is increased consensus that biomedical explanations for psychiatric disorders may reduce blame. This study found evidence supporting that consensus. This study provides an empirical foundation to inform ongoing work on the psychosocial implications of psychiatric genomics research in non-Western contexts.
- Full Text:
- Date Issued: 2020
Exploring intermolecular contacts in multi-substituted benzaldehyde derivatives: X-ray, Hirshfeld surface and lattice energy analyses
- Hulushe, Siya T, Manyeruke, Meloddy H, Louzada, Marcel, Rigin, Sergei, Hosten, Eric C, Watkins, Gareth M
- Authors: Hulushe, Siya T , Manyeruke, Meloddy H , Louzada, Marcel , Rigin, Sergei , Hosten, Eric C , Watkins, Gareth M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148483 , vital:38743 , DOI: 10.1039/C9RA10752E
- Description: Crystal structures of six benzaldehyde derivatives (1–6) have been determined and their supramolecular networks were established by an X-ray crystallographic study. The study has shown that the compounds are linked by various intermolecular interactions such as weak C–H⋯O hydrogen bonding, and C–H⋯π, π–π and halogen bonding interactions which consolidate and strengthen the formation of these molecular assemblies. The carbonyl group generates diverse synthons in 1–6 via intermolecular C–H⋯O hydrogen bonds. An interplay of C–H⋯O hydrogen bonds, and C–H⋯π and π–π stacking interactions facilitates the formation of multi-dimensional supramolecular networks. Crystal packings in 4 and 5 are further generated by type I halogen⋯halogen bonding interactions. The differences in crystal packing are represented by variation of substitution positions in the compounds. Structure 3 is isomorphous with 4 but there are subtle differences in their crystal packing.
- Full Text:
- Date Issued: 2020
- Authors: Hulushe, Siya T , Manyeruke, Meloddy H , Louzada, Marcel , Rigin, Sergei , Hosten, Eric C , Watkins, Gareth M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148483 , vital:38743 , DOI: 10.1039/C9RA10752E
- Description: Crystal structures of six benzaldehyde derivatives (1–6) have been determined and their supramolecular networks were established by an X-ray crystallographic study. The study has shown that the compounds are linked by various intermolecular interactions such as weak C–H⋯O hydrogen bonding, and C–H⋯π, π–π and halogen bonding interactions which consolidate and strengthen the formation of these molecular assemblies. The carbonyl group generates diverse synthons in 1–6 via intermolecular C–H⋯O hydrogen bonds. An interplay of C–H⋯O hydrogen bonds, and C–H⋯π and π–π stacking interactions facilitates the formation of multi-dimensional supramolecular networks. Crystal packings in 4 and 5 are further generated by type I halogen⋯halogen bonding interactions. The differences in crystal packing are represented by variation of substitution positions in the compounds. Structure 3 is isomorphous with 4 but there are subtle differences in their crystal packing.
- Full Text:
- Date Issued: 2020
F-and F+-band radioluminescence and the influence of annealing on its emission spectra in Al2O3: C, Mg:
- Chithambo, Makaiko L, Kalita, Jitumani M, Finch, A A
- Authors: Chithambo, Makaiko L , Kalita, Jitumani M , Finch, A A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150130 , vital:38942 , https://doi.org/10.1016/j.radmeas.2020.106306
- Description: Radioluminescence spectra of Al2O3:C,Mg monitored at temperatures up to 400 °C is reported. Measurements were made on samples either as received or on ones annealed at 1200 °C. Radioluminescence is observed at 410 nm for the unannealed sample but principally at 330 and 410 nm in the annealed sample with the emission at 330 nm dominant. Both bands are subject to thermal quenching but the change for the F+ band is atypical. Temperature induced effects on these and other bands are discussed, as are complementary measurements of thermoluminescence spectra.
- Full Text:
- Date Issued: 2020
- Authors: Chithambo, Makaiko L , Kalita, Jitumani M , Finch, A A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150130 , vital:38942 , https://doi.org/10.1016/j.radmeas.2020.106306
- Description: Radioluminescence spectra of Al2O3:C,Mg monitored at temperatures up to 400 °C is reported. Measurements were made on samples either as received or on ones annealed at 1200 °C. Radioluminescence is observed at 410 nm for the unannealed sample but principally at 330 and 410 nm in the annealed sample with the emission at 330 nm dominant. Both bands are subject to thermal quenching but the change for the F+ band is atypical. Temperature induced effects on these and other bands are discussed, as are complementary measurements of thermoluminescence spectra.
- Full Text:
- Date Issued: 2020
Fabrication of dye-sensitized solar cells based on push-pull asymmetrical substituted zinc and copper phthalocyanines and reduced graphene oxide nanosheet:
- Chindeka, Francis, Mashazi, Philani N, Britton, Jonathan, Oluwole, David O, Mapukata, Sivuyisiwe, Nyokong, Tebello
- Authors: Chindeka, Francis , Mashazi, Philani N , Britton, Jonathan , Oluwole, David O , Mapukata, Sivuyisiwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149076 , vital:38802 , https://doi.org/10.1016/j.jphotochem.2020.112612
- Description: Dye sensitized solar cells (DSSCs) were fabricated by using 2(3,5-biscarboxyphenoxy), 9(10), 16(17), 23(24)-tri(tertbutyl) phthalocyaninato Cu (4) and Zn (5) complexes as dyes on the ITO-TiO2 photoanodes containing reduced graphene oxide nanosheets (rGONS) or nitrogen-doped rGONS (NrGONS). The evaluation of the assembled DSSCs revealed that using ITO-TiO2-NrGONS-CuPc photoanode had the highest fill factor (FF) and power conversion efficiency (ɳ) of 69% and 4.36% respectively. These results show that the asymmetrical phthalocyanine complexes (4) and (5) exhibit significant improvement on the performance of the DSSC compared to our previous work on symmetrical carboxylated phthalocyanines with ɳ = 3.19%.
- Full Text:
- Date Issued: 2020
- Authors: Chindeka, Francis , Mashazi, Philani N , Britton, Jonathan , Oluwole, David O , Mapukata, Sivuyisiwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149076 , vital:38802 , https://doi.org/10.1016/j.jphotochem.2020.112612
- Description: Dye sensitized solar cells (DSSCs) were fabricated by using 2(3,5-biscarboxyphenoxy), 9(10), 16(17), 23(24)-tri(tertbutyl) phthalocyaninato Cu (4) and Zn (5) complexes as dyes on the ITO-TiO2 photoanodes containing reduced graphene oxide nanosheets (rGONS) or nitrogen-doped rGONS (NrGONS). The evaluation of the assembled DSSCs revealed that using ITO-TiO2-NrGONS-CuPc photoanode had the highest fill factor (FF) and power conversion efficiency (ɳ) of 69% and 4.36% respectively. These results show that the asymmetrical phthalocyanine complexes (4) and (5) exhibit significant improvement on the performance of the DSSC compared to our previous work on symmetrical carboxylated phthalocyanines with ɳ = 3.19%.
- Full Text:
- Date Issued: 2020
Fabrication of electrospun fibers from a porphyrin linked to polyacrylonitrile polymer for photocatalytic transformation of phenols
- Jones, Ben, Mafukidze, Donovan M, Nyokong, Tebello
- Authors: Jones, Ben , Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186196 , vital:44472 , xlink:href="https://doi.org/10.1016/j.molstruc.2020.128191"
- Description: A novel mono-porphyrin (2) was employed for the photodegradation of 4-chlorophenol and 4-n-nonylphenol at pH 10.60. A partially modified polyacrylonitrile (PAN) polymer was utilized only as a support system for the photosensitiser to allow the formation of a covalent linkage. Complex 2 showed singlet oxygen values of 0.70 in dimethyl formamide and when conjugated (2-PAN) showed 0.39 in water. When employed against 4-chlorophenol a degradation efficiency (η) of 29.1% was achieved at 0.20 mol L−1 over a period of 10 min. When employed against 4-n-nonylphenol we obtained a η of 26.7% at 0.17 mol L−1 over a period of 10 min.
- Full Text:
- Date Issued: 2020
- Authors: Jones, Ben , Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186196 , vital:44472 , xlink:href="https://doi.org/10.1016/j.molstruc.2020.128191"
- Description: A novel mono-porphyrin (2) was employed for the photodegradation of 4-chlorophenol and 4-n-nonylphenol at pH 10.60. A partially modified polyacrylonitrile (PAN) polymer was utilized only as a support system for the photosensitiser to allow the formation of a covalent linkage. Complex 2 showed singlet oxygen values of 0.70 in dimethyl formamide and when conjugated (2-PAN) showed 0.39 in water. When employed against 4-chlorophenol a degradation efficiency (η) of 29.1% was achieved at 0.20 mol L−1 over a period of 10 min. When employed against 4-n-nonylphenol we obtained a η of 26.7% at 0.17 mol L−1 over a period of 10 min.
- Full Text:
- Date Issued: 2020
First candidates for γ vibrational bands built on the [505] 11/2− neutron orbital in odd-A Dy isotopes:
- Majola, S N T, Sithole, M A, Mdletshe, L, Hartley, D, Timár, J, Nyakó, B M, Allmond, J M, Bark, R A, Beausang, C, Bianco, L, Bucher, T D, Bvumbi, S P, Carpenter, M P, Chiara, C J, Cooper, N, Cullen, D M, Curien, D, Dinoko, T S, Gall, B J P, Garrett, P E, Greenlees, P T, Hirvonen, J, Jakobsson, U, Jones, P M, Julin, R, Juutinen, S, Ketelhut, S, Keswa, B V, Kondev, F G, Korichi, A, Kulp, W D, Lauritsen, T, Lawrie, E A, Makhathini, L, Masiteng, P L, Maqabuka, B, McCutchan, E A, Miller, D, Miller, S, Minkova, A, Msebi, L, Mthembu, S H, Ndayishmiye, J, Nieminen, P, Ngcobo, P Z, Ntshamgase, S S, Orce, J N, Peura, P, Rahkila, P, Redon, N, Riedinger, L L, Riley, M A, Roux, D G, Ruotsalainen, P, Piot, J, Saren, J, Sharpey-Schafer, J F, Scholey, C, Shirinda, O, Simpson, J, Sorri, J, Stefansecu, I, Stolze, S, Uusitalo, J, Wang, X, Werner, V, Wood, J L, Yu, C-H, Zhu, S, Zimba, G
- Authors: Majola, S N T , Sithole, M A , Mdletshe, L , Hartley, D , Timár, J , Nyakó, B M , Allmond, J M , Bark, R A , Beausang, C , Bianco, L , Bucher, T D , Bvumbi, S P , Carpenter, M P , Chiara, C J , Cooper, N , Cullen, D M , Curien, D , Dinoko, T S , Gall, B J P , Garrett, P E , Greenlees, P T , Hirvonen, J , Jakobsson, U , Jones, P M , Julin, R , Juutinen, S , Ketelhut, S , Keswa, B V , Kondev, F G , Korichi, A , Kulp, W D , Lauritsen, T , Lawrie, E A , Makhathini, L , Masiteng, P L , Maqabuka, B , McCutchan, E A , Miller, D , Miller, S , Minkova, A , Msebi, L , Mthembu, S H , Ndayishmiye, J , Nieminen, P , Ngcobo, P Z , Ntshamgase, S S , Orce, J N , Peura, P , Rahkila, P , Redon, N , Riedinger, L L , Riley, M A , Roux, D G , Ruotsalainen, P , Piot, J , Saren, J , Sharpey-Schafer, J F , Scholey, C , Shirinda, O , Simpson, J , Sorri, J , Stefansecu, I , Stolze, S , Uusitalo, J , Wang, X , Werner, V , Wood, J L , Yu, C-H , Zhu, S , Zimba, G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148827 , vital:38777 , https://0-journals.aps.org.wam.seals.ac.za/prc/abstract/10.1103/PhysRevC.101.044312
- Description: Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following the 155Gd(α,2n)157Dy and 148Nd(12C,5n)155Dy reactions at 25 and 65 MeV, respectively. We report high-K bands, which are conjectured to be the first candidates of a Kπ=2+γ vibrational band, built on the [505]11/2− neutron orbital, in both odd-A155,157Dy isotopes. The coupling of the first excited K=0+ states or the so-called β vibrational bands at 661 and 676 keV in 154Dy and 156Dy to the [505]11/2− orbital, to produce a Kπ=11/2− band, was not observed in both 155Dy and 157Dy, respectively. The implication of these findings on the interpretation of the first excited 0+ states in the core nuclei 154Dy and 156Dy are also discussed.
- Full Text:
- Date Issued: 2020
- Authors: Majola, S N T , Sithole, M A , Mdletshe, L , Hartley, D , Timár, J , Nyakó, B M , Allmond, J M , Bark, R A , Beausang, C , Bianco, L , Bucher, T D , Bvumbi, S P , Carpenter, M P , Chiara, C J , Cooper, N , Cullen, D M , Curien, D , Dinoko, T S , Gall, B J P , Garrett, P E , Greenlees, P T , Hirvonen, J , Jakobsson, U , Jones, P M , Julin, R , Juutinen, S , Ketelhut, S , Keswa, B V , Kondev, F G , Korichi, A , Kulp, W D , Lauritsen, T , Lawrie, E A , Makhathini, L , Masiteng, P L , Maqabuka, B , McCutchan, E A , Miller, D , Miller, S , Minkova, A , Msebi, L , Mthembu, S H , Ndayishmiye, J , Nieminen, P , Ngcobo, P Z , Ntshamgase, S S , Orce, J N , Peura, P , Rahkila, P , Redon, N , Riedinger, L L , Riley, M A , Roux, D G , Ruotsalainen, P , Piot, J , Saren, J , Sharpey-Schafer, J F , Scholey, C , Shirinda, O , Simpson, J , Sorri, J , Stefansecu, I , Stolze, S , Uusitalo, J , Wang, X , Werner, V , Wood, J L , Yu, C-H , Zhu, S , Zimba, G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148827 , vital:38777 , https://0-journals.aps.org.wam.seals.ac.za/prc/abstract/10.1103/PhysRevC.101.044312
- Description: Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following the 155Gd(α,2n)157Dy and 148Nd(12C,5n)155Dy reactions at 25 and 65 MeV, respectively. We report high-K bands, which are conjectured to be the first candidates of a Kπ=2+γ vibrational band, built on the [505]11/2− neutron orbital, in both odd-A155,157Dy isotopes. The coupling of the first excited K=0+ states or the so-called β vibrational bands at 661 and 676 keV in 154Dy and 156Dy to the [505]11/2− orbital, to produce a Kπ=11/2− band, was not observed in both 155Dy and 157Dy, respectively. The implication of these findings on the interpretation of the first excited 0+ states in the core nuclei 154Dy and 156Dy are also discussed.
- Full Text:
- Date Issued: 2020
First record of an indigenous South African parasitoid wasp on an imported biological control agent, the water hyacinth hopper
- Kraus, Emily C, Coetzee, Julie A, van Noort, Simon, Olmi, Massimo
- Authors: Kraus, Emily C , Coetzee, Julie A , van Noort, Simon , Olmi, Massimo
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417700 , vital:71479 , xlink:href="https://doi.org/10.1080/09583157.2019.1660306"
- Description: Water hyacinth, Pontederia crassipes (Martius) [≡Eichhornia crassip es (Martius) Solms-Laubach] (Pontederiaceae), is native to South America, but has expanded its range to many other regions of the world including South Africa. Megamelus scutellaris Berg (Hemiptera: Delphacidae) was released as a biological control agent and has established in several regions. Recently, the indigenous species Echthrodelphax migratorius Benoit, (Hymenoptera: Dryinidae) was discovered in South Africa parasitising M. scutellaris. This newly discovered relationship might have repercussions for the efficacy of biological control of water hyacinth by the delphacid. The wasp may negatively impact M. scutellaris populations making it difficult for the agent to successfully manage the invasive weed. Contrarily, the parasitoid may be beneficial by keeping the M. scutellaris populations stable, serving as a natural enemy.
- Full Text:
- Date Issued: 2020
- Authors: Kraus, Emily C , Coetzee, Julie A , van Noort, Simon , Olmi, Massimo
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417700 , vital:71479 , xlink:href="https://doi.org/10.1080/09583157.2019.1660306"
- Description: Water hyacinth, Pontederia crassipes (Martius) [≡Eichhornia crassip es (Martius) Solms-Laubach] (Pontederiaceae), is native to South America, but has expanded its range to many other regions of the world including South Africa. Megamelus scutellaris Berg (Hemiptera: Delphacidae) was released as a biological control agent and has established in several regions. Recently, the indigenous species Echthrodelphax migratorius Benoit, (Hymenoptera: Dryinidae) was discovered in South Africa parasitising M. scutellaris. This newly discovered relationship might have repercussions for the efficacy of biological control of water hyacinth by the delphacid. The wasp may negatively impact M. scutellaris populations making it difficult for the agent to successfully manage the invasive weed. Contrarily, the parasitoid may be beneficial by keeping the M. scutellaris populations stable, serving as a natural enemy.
- Full Text:
- Date Issued: 2020
Flower orientation in Gloriosa superba (Colchicaceae) promotes cross-pollination via butterfly wings:
- Daniels, Ryan J, Johnson, Steven D, Peter, Craig I
- Authors: Daniels, Ryan J , Johnson, Steven D , Peter, Craig I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150141 , vital:38943 , https://0-doi.org.wam.seals.ac.za/10.1093/aob/mcaa048
- Description: Complex modifications of angiosperm flowers often function for precise pollen placement on pollinators and to promote cross-pollination. We explore the functional significance of the unusually elaborate morphology of Gloriosa superba flowers, which are divided into one hermaphrodite meranthium and five male meranthia (functional pollination units of a single flower). We used controlled pollination experiments, floral measurements, pollen load analyses and visitor observations in four populations of G. superba in South Africa to determine the breeding system, mechanism of pollination and role of flower in the promotion of cross-pollination.
- Full Text:
- Date Issued: 2020
- Authors: Daniels, Ryan J , Johnson, Steven D , Peter, Craig I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150141 , vital:38943 , https://0-doi.org.wam.seals.ac.za/10.1093/aob/mcaa048
- Description: Complex modifications of angiosperm flowers often function for precise pollen placement on pollinators and to promote cross-pollination. We explore the functional significance of the unusually elaborate morphology of Gloriosa superba flowers, which are divided into one hermaphrodite meranthium and five male meranthia (functional pollination units of a single flower). We used controlled pollination experiments, floral measurements, pollen load analyses and visitor observations in four populations of G. superba in South Africa to determine the breeding system, mechanism of pollination and role of flower in the promotion of cross-pollination.
- Full Text:
- Date Issued: 2020
Foraging wild food in urban spaces: The contribution of wild foods to urban dietary diversity in South Africa
- Garekae, Hesekia, Shackleton, Charlie M
- Authors: Garekae, Hesekia , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176368 , vital:42688 , https://doi.org/10.3390/su12020678
- Description: Globally, approximately one billion people benefit from contributions of wild foods to their food security and dietary diversity. Wild foods are known to be important in rural communities in terms of food and micronutrient provision, diversifying diets, reducing vulnerability to non-communicable diseases and overall health. However, the potential contribution of wild foods towards food security and dietary diversity in urban food systems has been largely overlooked. This study examined the contribution of wild foods to household dietary diversity in two towns in South Africa, based on a survey of 137 households.
- Full Text:
- Date Issued: 2020
- Authors: Garekae, Hesekia , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176368 , vital:42688 , https://doi.org/10.3390/su12020678
- Description: Globally, approximately one billion people benefit from contributions of wild foods to their food security and dietary diversity. Wild foods are known to be important in rural communities in terms of food and micronutrient provision, diversifying diets, reducing vulnerability to non-communicable diseases and overall health. However, the potential contribution of wild foods towards food security and dietary diversity in urban food systems has been largely overlooked. This study examined the contribution of wild foods to household dietary diversity in two towns in South Africa, based on a survey of 137 households.
- Full Text:
- Date Issued: 2020
Forays into contemporary South African theatre
- Authors: Krueger, Anton
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229578 , vital:49689 , xlink:href="https://doi.org/10.1080/10137548.2021.1963112"
- Description: Trying to keep up with what is going on in South African theatre today is an endlessly renewing process. The word ‘foray’ has associations of brief incursions into foreign territory. It’s an almost hesitant word, a venture into unexplored terrain. This hesitation feels apt in the sense that (at the time of writing), any description of a pre-Covid theatre is bound to feel strange. The landscape has shifted, and nobody is quite sure how things will look in a year from now. Nevertheless, this is a rich compendium of relatively recent theatre, as seen from within the country and also from the vantage of a global perspective. Almost all of the essays are drawn from a 2017 conference held in Brussels at the Université Libre de Bruxelles, called: ‘New Stage Idioms: South African Drama, Theatre and Performance in the Twenty-first Century.’Although the tone remains scholarly, the inclusion of different kinds of writers – not only academics but activists, playwrights and journalists – prevents the work from becoming overly dry.
- Full Text:
- Date Issued: 2020
- Authors: Krueger, Anton
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229578 , vital:49689 , xlink:href="https://doi.org/10.1080/10137548.2021.1963112"
- Description: Trying to keep up with what is going on in South African theatre today is an endlessly renewing process. The word ‘foray’ has associations of brief incursions into foreign territory. It’s an almost hesitant word, a venture into unexplored terrain. This hesitation feels apt in the sense that (at the time of writing), any description of a pre-Covid theatre is bound to feel strange. The landscape has shifted, and nobody is quite sure how things will look in a year from now. Nevertheless, this is a rich compendium of relatively recent theatre, as seen from within the country and also from the vantage of a global perspective. Almost all of the essays are drawn from a 2017 conference held in Brussels at the Université Libre de Bruxelles, called: ‘New Stage Idioms: South African Drama, Theatre and Performance in the Twenty-first Century.’Although the tone remains scholarly, the inclusion of different kinds of writers – not only academics but activists, playwrights and journalists – prevents the work from becoming overly dry.
- Full Text:
- Date Issued: 2020
Formulation and Characterisation of a Combination Captopril and Hydrochlorothiazide Microparticulate Dosage Form
- Chikukwa, Mellisa T R, Walker, Roderick B, Khamanga, Sandile M
- Authors: Chikukwa, Mellisa T R , Walker, Roderick B , Khamanga, Sandile M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183200 , vital:43926 , xlink:href="https://doi.org/10.3390/pharmaceutics12080712"
- Description: Cardiovascular diseases such as hypertension and cardiac failure in South African children and adolescents are effectively managed long term, using a combination treatment of captopril and hydrochlorothiazide. The majority of commercially available pharmaceutical products are designed for adult patients and require extemporaneous manipulation, prior to administration to paediatric patients. There is a need to develop an age appropriate microparticulate dosing technology that is easy to swallow, dose and alter doses whilst overcoming the pharmacokinetic challenges of short half-life and biphasic pharmacokinetic disposition exhibited by hydrochlorothiazide and captopril. An emulsion solvent evaporation approach using different combinations of polymers was used to manufacture captopril and hydrochlorothiazide microparticles. Design of experiments was used to develop and analyse experimental data, and identifyoptimum formulation and process conditions for the preparation of the microparticles. Characterisation studies to establish encapsulation efficiency, in vitro release, shape, size and morphology of the microparticles were undertaken. The microparticles produced were in the micrometre size range, with an encapsulation efficiency >75% for both hydrochlorothiazide and captopril. The microparticulate technology is able to offer potential resolution to the half-life mediated dosing frequency of captopril as sustained release of the molecule was observed over a 12-h period. The release of hydrochlorothiazide of >80% suggests an improvement in solubility limited dissolution.
- Full Text:
- Date Issued: 2020
- Authors: Chikukwa, Mellisa T R , Walker, Roderick B , Khamanga, Sandile M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183200 , vital:43926 , xlink:href="https://doi.org/10.3390/pharmaceutics12080712"
- Description: Cardiovascular diseases such as hypertension and cardiac failure in South African children and adolescents are effectively managed long term, using a combination treatment of captopril and hydrochlorothiazide. The majority of commercially available pharmaceutical products are designed for adult patients and require extemporaneous manipulation, prior to administration to paediatric patients. There is a need to develop an age appropriate microparticulate dosing technology that is easy to swallow, dose and alter doses whilst overcoming the pharmacokinetic challenges of short half-life and biphasic pharmacokinetic disposition exhibited by hydrochlorothiazide and captopril. An emulsion solvent evaporation approach using different combinations of polymers was used to manufacture captopril and hydrochlorothiazide microparticles. Design of experiments was used to develop and analyse experimental data, and identifyoptimum formulation and process conditions for the preparation of the microparticles. Characterisation studies to establish encapsulation efficiency, in vitro release, shape, size and morphology of the microparticles were undertaken. The microparticles produced were in the micrometre size range, with an encapsulation efficiency >75% for both hydrochlorothiazide and captopril. The microparticulate technology is able to offer potential resolution to the half-life mediated dosing frequency of captopril as sustained release of the molecule was observed over a 12-h period. The release of hydrochlorothiazide of >80% suggests an improvement in solubility limited dissolution.
- Full Text:
- Date Issued: 2020
Formulation optimization of smart thermosetting lamotrigine loaded hydrogels using response surface methodology, box benhken design and artificial neural networks
- Melamane, Siyabonga, Walker, Roderick B, Khamanga, Sandile M
- Authors: Melamane, Siyabonga , Walker, Roderick B , Khamanga, Sandile M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183265 , vital:43936 , xlink:href="https://doi.org/10.1080/03639045.2020.1791163"
- Description: The aim of this research was to develop lamotrigine containing thermosetting hydrogel for intranasal administration to manage and treat generalized epilepsy. Thermosetting hydrogels were prepared using different ratios of poloxamer 407 (L127), poloxamer 188 (L68) and CarbopolVR 974 P NF (C974) using the cold production process. The in situ thermosetting hydrogel was optimized using Box Behken design. Co-solvency approach was used to increase the solubility of lamotrigine by dissolving it in propylene glycol and polyethylene glycol 400 (0.2: 0.8) and the resultant solution was incorporated in the hydrogel to manufacture an LTG hydrogel. The presence of a higher amount of L127 resulted in higher viscosity at 22 0C and 34 0C and decreased the overall release of LTG. An increase in the amount of C974 resulted in a decrease in the pH of the hydrogel. The results show that formulations F10, F12, F13, F14, F15, F16 and F17 exhibited acceptable thermosetting behavior, pH and released adequate Lamotrigine above the minimum effective concentration to treat generalized epilepsy. The optimized formulation exhibited acceptable thermosetting behavior, pH and lamotrigine release but formed a stiff gel at 22 0C. The average LTG content of the optimized hydrogel was 5.00 ± 0.0225mg/ml with % recovery of 99.17%. The amount of LTG released at 12 h from the optimized hydrogel was 3.21 ± 0.0155mg and will be therapeutically effective in the brain after absorption via the olfactory region in the nasal cavity.
- Full Text:
- Date Issued: 2020
- Authors: Melamane, Siyabonga , Walker, Roderick B , Khamanga, Sandile M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183265 , vital:43936 , xlink:href="https://doi.org/10.1080/03639045.2020.1791163"
- Description: The aim of this research was to develop lamotrigine containing thermosetting hydrogel for intranasal administration to manage and treat generalized epilepsy. Thermosetting hydrogels were prepared using different ratios of poloxamer 407 (L127), poloxamer 188 (L68) and CarbopolVR 974 P NF (C974) using the cold production process. The in situ thermosetting hydrogel was optimized using Box Behken design. Co-solvency approach was used to increase the solubility of lamotrigine by dissolving it in propylene glycol and polyethylene glycol 400 (0.2: 0.8) and the resultant solution was incorporated in the hydrogel to manufacture an LTG hydrogel. The presence of a higher amount of L127 resulted in higher viscosity at 22 0C and 34 0C and decreased the overall release of LTG. An increase in the amount of C974 resulted in a decrease in the pH of the hydrogel. The results show that formulations F10, F12, F13, F14, F15, F16 and F17 exhibited acceptable thermosetting behavior, pH and released adequate Lamotrigine above the minimum effective concentration to treat generalized epilepsy. The optimized formulation exhibited acceptable thermosetting behavior, pH and lamotrigine release but formed a stiff gel at 22 0C. The average LTG content of the optimized hydrogel was 5.00 ± 0.0225mg/ml with % recovery of 99.17%. The amount of LTG released at 12 h from the optimized hydrogel was 3.21 ± 0.0155mg and will be therapeutically effective in the brain after absorption via the olfactory region in the nasal cavity.
- Full Text:
- Date Issued: 2020
From the Booth to the Dock: 2018 elections in Zimbabwe and the elusive search for electoral integrity
- Mwonzora, Gift, Xaba, Mzingaye Brilliant
- Authors: Mwonzora, Gift , Xaba, Mzingaye Brilliant
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159946 , vital:40358 , https://doi.org/10.1080/14662043.2020.1813457
- Description: The issue of presidential election petitions seems to be repeating itself with regularity in much of Africa, thus warranting the need for thorough analysis. Utilising the 2018 presidential election petition in Zimbabwe, the article examines whether electoral integrity and legitimacy can be derived from court-based action. Data for this article was gleaned from case law analysis, review of expert analysis from constitutional lawyers and election experts, video evidence, in-depth and critical reading of grey material. The article concludes that there are limitations in relying on litigation in seeking to realise electoral justice in much of Africa, including in Zimbabwe.
- Full Text:
- Date Issued: 2020
- Authors: Mwonzora, Gift , Xaba, Mzingaye Brilliant
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159946 , vital:40358 , https://doi.org/10.1080/14662043.2020.1813457
- Description: The issue of presidential election petitions seems to be repeating itself with regularity in much of Africa, thus warranting the need for thorough analysis. Utilising the 2018 presidential election petition in Zimbabwe, the article examines whether electoral integrity and legitimacy can be derived from court-based action. Data for this article was gleaned from case law analysis, review of expert analysis from constitutional lawyers and election experts, video evidence, in-depth and critical reading of grey material. The article concludes that there are limitations in relying on litigation in seeking to realise electoral justice in much of Africa, including in Zimbabwe.
- Full Text:
- Date Issued: 2020
Fruits of the Veld: Ecological and Socioeconomic Patterns of Natural Resource Use across South Africa
- Sardeshpande, Mallika, Shackleton, Charlie M
- Authors: Sardeshpande, Mallika , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175756 , vital:42621 , https://doi.org/10.1007/s10745-020-00185-x
- Description: Wild edible fruits (WEFs) are important non-timber forest products (NTFP) that are commonly grouped with other wild foods or NTFPs in general. We hypothesize that WEFs, other wild foods, and non-food NTFPs contribute in different ways to household economies. Using data collected through a survey of 503 households in South Africa, we describe patterns of use of WEFs across socioeconomic and geographical gradients and compare them to the patterns of use of other wild foods and non-food NTFPs. WEFs were used by one-fifth of all sampled households, independent of economic and urbanisation gradients and were grown in or collected mostly from surrounding areas. More households, usually in rural areas, used other wild foods and non-food NTFPs, which were often purchased from other collectors.
- Full Text:
- Date Issued: 2020
- Authors: Sardeshpande, Mallika , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175756 , vital:42621 , https://doi.org/10.1007/s10745-020-00185-x
- Description: Wild edible fruits (WEFs) are important non-timber forest products (NTFP) that are commonly grouped with other wild foods or NTFPs in general. We hypothesize that WEFs, other wild foods, and non-food NTFPs contribute in different ways to household economies. Using data collected through a survey of 503 households in South Africa, we describe patterns of use of WEFs across socioeconomic and geographical gradients and compare them to the patterns of use of other wild foods and non-food NTFPs. WEFs were used by one-fifth of all sampled households, independent of economic and urbanisation gradients and were grown in or collected mostly from surrounding areas. More households, usually in rural areas, used other wild foods and non-food NTFPs, which were often purchased from other collectors.
- Full Text:
- Date Issued: 2020
Fucoidan from Ecklonia maxima is a powerful inhibitor of the diabetes-related enzyme, Éø-glucosidase
- Daub, Chantal D, Mabate, Blessing, Malgas, Samkelo, Pletschke, Brett I
- Authors: Daub, Chantal D , Mabate, Blessing , Malgas, Samkelo , Pletschke, Brett I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425982 , vital:72304 , xlink:href="https://doi.org/10.1016/j.ijbiomac.2020.02.161"
- Description: Ecklonia maxima, an endemic South African seaweed, is a potential source of beneficial bioactive compounds. Among these compounds, fucoidan, a sulphated polysaccharide has a wide range of bioactivities including anti-diabetic activity. In this study, fucoidan was extracted from E. maxima by the hot water extraction method and then characterised by colorimetric assays for sugar composition. The extraction from E. maxima yielded 6.89% fucoidan which was found to contain 4.45 ± 0.25% L-fucose and 6.01 ± 0.53% sulphate. The water extracted E. maxima fucoidan had a low molecular weight of approximately 10 kDa. Structural studies (FT-IR, NMR and XRD) confirmed the structure and integrity of the fucoidan to be similar to previously studied fucoidans in literature. Finally, the activities of starch digestive enzymes; α-amylase and α-glucosidase, were investigated in the presence of the E. maxima fucoidan extract. Fucoidan from E. maxima was observed to be a potent mixed-type inhibitor of α-glucosidase with an IC50 range of 0.27–0.31 mg.ml-1, which was significantly lower than the commercial anti-diabetic standard, acarbose. Our present study demonstrated that fucoidan from E. maxima is a more powerful inhibitor compared to some standard anti-diabetic compounds and thus shows great potential for managing type 2 diabetes.
- Full Text:
- Date Issued: 2020
Fucoidan from Ecklonia maxima is a powerful inhibitor of the diabetes-related enzyme, Éø-glucosidase
- Authors: Daub, Chantal D , Mabate, Blessing , Malgas, Samkelo , Pletschke, Brett I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425982 , vital:72304 , xlink:href="https://doi.org/10.1016/j.ijbiomac.2020.02.161"
- Description: Ecklonia maxima, an endemic South African seaweed, is a potential source of beneficial bioactive compounds. Among these compounds, fucoidan, a sulphated polysaccharide has a wide range of bioactivities including anti-diabetic activity. In this study, fucoidan was extracted from E. maxima by the hot water extraction method and then characterised by colorimetric assays for sugar composition. The extraction from E. maxima yielded 6.89% fucoidan which was found to contain 4.45 ± 0.25% L-fucose and 6.01 ± 0.53% sulphate. The water extracted E. maxima fucoidan had a low molecular weight of approximately 10 kDa. Structural studies (FT-IR, NMR and XRD) confirmed the structure and integrity of the fucoidan to be similar to previously studied fucoidans in literature. Finally, the activities of starch digestive enzymes; α-amylase and α-glucosidase, were investigated in the presence of the E. maxima fucoidan extract. Fucoidan from E. maxima was observed to be a potent mixed-type inhibitor of α-glucosidase with an IC50 range of 0.27–0.31 mg.ml-1, which was significantly lower than the commercial anti-diabetic standard, acarbose. Our present study demonstrated that fucoidan from E. maxima is a more powerful inhibitor compared to some standard anti-diabetic compounds and thus shows great potential for managing type 2 diabetes.
- Full Text:
- Date Issued: 2020
Gamification of functional programming
- Chifamba, Tavonga D, Motara, Yusuf, M
- Authors: Chifamba, Tavonga D , Motara, Yusuf, M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428996 , vital:72552 , https://ieeexplore.ieee.org/abstract/document/9334096
- Description: This paper looks at the current state of how students learn the functional programming [FP] paradigm and how it can be improved by applying gamification. Multiple related works and research published by experts in the field are analyzed and examined. In conclusion, a possible way forward with regards to functional programming gamification design is proposed.
- Full Text:
- Date Issued: 2020
- Authors: Chifamba, Tavonga D , Motara, Yusuf, M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428996 , vital:72552 , https://ieeexplore.ieee.org/abstract/document/9334096
- Description: This paper looks at the current state of how students learn the functional programming [FP] paradigm and how it can be improved by applying gamification. Multiple related works and research published by experts in the field are analyzed and examined. In conclusion, a possible way forward with regards to functional programming gamification design is proposed.
- Full Text:
- Date Issued: 2020
Gamma-Ray and X-Ray Observations of the Periodic-repeater FRB 180916 during Active Phases:
- Tavani, M, Verrecchia, F, Casentini, C, Perri, M, Ursi, A, Pacciani,L, Pittori, C, Bulgarelli, A, Piano, G, Pilia, Maura, Bernardi, Gianni, Addis, A, Antonelli, L A, Argan, A, Baroncelli, L, Caraveo, P, Cattaneo, P W, Chen, A, Costa, E, Di Persio, G, Donnarumma, I, Evangelista, Y, Feroci, A, Ferrari, A, Fioretti, V, Lazzrotto, F, Longo, F, Morselli, A, Paoletti, F, Parmiggiani, N, Trois, A, Vercellone, S, Naldi, Giovanni, Pupillo, G, Bianchi, Germano, Puccetti, S
- Authors: Tavani, M , Verrecchia, F , Casentini, C , Perri, M , Ursi, A , Pacciani,L , Pittori, C , Bulgarelli, A , Piano, G , Pilia, Maura , Bernardi, Gianni , Addis, A , Antonelli, L A , Argan, A , Baroncelli, L , Caraveo, P , Cattaneo, P W , Chen, A , Costa, E , Di Persio, G , Donnarumma, I , Evangelista, Y , Feroci, A , Ferrari, A , Fioretti, V , Lazzrotto, F , Longo, F , Morselli, A , Paoletti, F , Parmiggiani, N , Trois, A , Vercellone, S , Naldi, Giovanni , Pupillo, G , Bianchi, Germano , Puccetti, S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148803 , vital:38775 , https://0-iopscience.iop.org.wam.seals.ac.za/article/10.3847/2041-8213/ab86b1/meta
- Description: FRB 180916 is a most intriguing source capable of producing repeating fast radio bursts with a periodic 16.3 day temporal pattern. The source is well positioned in a star-forming region in the outskirts of a nearby galaxy at 150 Mpc distance. In this Letter we report on the X-ray and γ-ray observations of FRB 180916 obtained by AGILE and Swift. We focused especially on the recurrent 5 day time intervals of enhanced radio bursting. In particular, we report on the results obtained in the time intervals 2020 February 3–8, 2020 February 25, 2020 March 5–10, and 2020 March 22–28 during a multiwavelength campaign involving high-energy and radio observations of FRB 180916.
- Full Text:
- Date Issued: 2020
- Authors: Tavani, M , Verrecchia, F , Casentini, C , Perri, M , Ursi, A , Pacciani,L , Pittori, C , Bulgarelli, A , Piano, G , Pilia, Maura , Bernardi, Gianni , Addis, A , Antonelli, L A , Argan, A , Baroncelli, L , Caraveo, P , Cattaneo, P W , Chen, A , Costa, E , Di Persio, G , Donnarumma, I , Evangelista, Y , Feroci, A , Ferrari, A , Fioretti, V , Lazzrotto, F , Longo, F , Morselli, A , Paoletti, F , Parmiggiani, N , Trois, A , Vercellone, S , Naldi, Giovanni , Pupillo, G , Bianchi, Germano , Puccetti, S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148803 , vital:38775 , https://0-iopscience.iop.org.wam.seals.ac.za/article/10.3847/2041-8213/ab86b1/meta
- Description: FRB 180916 is a most intriguing source capable of producing repeating fast radio bursts with a periodic 16.3 day temporal pattern. The source is well positioned in a star-forming region in the outskirts of a nearby galaxy at 150 Mpc distance. In this Letter we report on the X-ray and γ-ray observations of FRB 180916 obtained by AGILE and Swift. We focused especially on the recurrent 5 day time intervals of enhanced radio bursting. In particular, we report on the results obtained in the time intervals 2020 February 3–8, 2020 February 25, 2020 March 5–10, and 2020 March 22–28 during a multiwavelength campaign involving high-energy and radio observations of FRB 180916.
- Full Text:
- Date Issued: 2020
Genetic diversity and morphological variation in African boxthorn (Lycium ferocissimum)–characterising the target weed for biological control
- McCulloch, Graham A, Mauda, Evans V, Chari, L D, Martin, Grant D, Gurdasani, Komal, Morin, L, Walter, G H, Raghu, S
- Authors: McCulloch, Graham A , Mauda, Evans V , Chari, L D , Martin, Grant D , Gurdasani, Komal , Morin, L , Walter, G H , Raghu, S
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423474 , vital:72064 , xlink:href="https://doi.org/10.1016/j.biocontrol.2020.104206"
- Description: Lycium ferocissimum (African boxthorn) is a Weed of National Significance in Australia. Biological control may have potential to manage this weed, but taxonomic uncertainty needs to be addressed first to facilitate searches for potential agents. We sampled putative L. ferocissimum (i.e. tentatively identified morphologically in the field) across its native range in South Africa and introduced range in Australia. Morphometric and genetic analyses were conducted to confirm the species identity of these samples, and to assess morphological and genetic variation across both ranges. All samples collected in Australia were confirmed as L. ferocissimum, with no evidence of hybridisation with any other Lycium species. Nuclear and chloroplast genetic diversity within L. ferocissimum across both South Africa and Australia was low, with no evidence of genetic structure. One of the two common chloroplast haplotypes found across Australia was found at only two sites in South Africa, both near Cape Town, suggesting that the Australian lineage may have originated from this region. Ten samples from South Africa putatively identified in the field as L. ferocissimum were genetically characterised as different (unidentified) Lycium species. Our morphometric analyses across different Lycium species in South Africa did not identify any leaf or floral characteristics unique to L. ferocissimum, and thus morphological identification of the latter species in its native range may remain problematic. To ensure the correct Lycium species is surveyed for candidate biological control agents we suggest that individuals should be permanently tagged and putative morphological determinations supplemented with genetic analyses to confirm species identity.
- Full Text:
- Date Issued: 2020
- Authors: McCulloch, Graham A , Mauda, Evans V , Chari, L D , Martin, Grant D , Gurdasani, Komal , Morin, L , Walter, G H , Raghu, S
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423474 , vital:72064 , xlink:href="https://doi.org/10.1016/j.biocontrol.2020.104206"
- Description: Lycium ferocissimum (African boxthorn) is a Weed of National Significance in Australia. Biological control may have potential to manage this weed, but taxonomic uncertainty needs to be addressed first to facilitate searches for potential agents. We sampled putative L. ferocissimum (i.e. tentatively identified morphologically in the field) across its native range in South Africa and introduced range in Australia. Morphometric and genetic analyses were conducted to confirm the species identity of these samples, and to assess morphological and genetic variation across both ranges. All samples collected in Australia were confirmed as L. ferocissimum, with no evidence of hybridisation with any other Lycium species. Nuclear and chloroplast genetic diversity within L. ferocissimum across both South Africa and Australia was low, with no evidence of genetic structure. One of the two common chloroplast haplotypes found across Australia was found at only two sites in South Africa, both near Cape Town, suggesting that the Australian lineage may have originated from this region. Ten samples from South Africa putatively identified in the field as L. ferocissimum were genetically characterised as different (unidentified) Lycium species. Our morphometric analyses across different Lycium species in South Africa did not identify any leaf or floral characteristics unique to L. ferocissimum, and thus morphological identification of the latter species in its native range may remain problematic. To ensure the correct Lycium species is surveyed for candidate biological control agents we suggest that individuals should be permanently tagged and putative morphological determinations supplemented with genetic analyses to confirm species identity.
- Full Text:
- Date Issued: 2020
Genetics of schizophrenia in the South African Xhosa
- Gulsuner, S, Stein, D J, Susser, E S, Sibeko, G, Pretorius, A, Walsh, T, Majara, L, Mndini, M M, Mqulwana, S G, Ntola, O A, Casadei, S, Zingela, Zukiswa, Nagdee, M, Ramesar, R S, King, M-C, McClellan, J M, Ngqengelele, L L, Korchina, V, van der Merwe, C, Malan, M, Fader, K M, Feng, M, Willoughby, E, Munzi, D, Andrews, H F, Gur, R C, Gibbs, R A
- Authors: Gulsuner, S , Stein, D J , Susser, E S , Sibeko, G , Pretorius, A , Walsh, T , Majara, L , Mndini, M M , Mqulwana, S G , Ntola, O A , Casadei, S , Zingela, Zukiswa , Nagdee, M , Ramesar, R S , King, M-C , McClellan, J M , Ngqengelele, L L , Korchina, V , van der Merwe, C , Malan, M , Fader, K M , Feng, M , Willoughby, E , Munzi, D , Andrews, H F , Gur, R C , Gibbs, R A
- Date: 2020
- Subjects: Schizophrenia -- Diagnosis -- Cross-cultural studies , Medical genetics , Xhosa (African people)
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/4217 , vital:44044 , https://doi.org/10.1126/science.aay8833
- Description: Africa, the ancestral home of all modern humans, is the most informative continent for understanding the human genome and its contribution to complex disease. To better understand the genetics of schizophrenia, we studied the illness in the Xhosa population of South Africa, recruiting 909 cases and 917 age-, gender-, and residence-matched controls. Individuals with schizophrenia were significantly more likely than controls to harbor private, severely damaging mutations in genes that are critical to synaptic function, including neural circuitry mediated by the neurotransmitters glutamine, γ-aminobutyric acid, and dopamine. Schizophrenia is genetically highly heterogeneous, involving severe ultrarare mutations in genes that are critical to synaptic plasticity. The depth of genetic variation in Africa revealed this relationship with a moderate sample size and informed our understanding of the genetics of schizophrenia worldwide.
- Full Text:
- Date Issued: 2020
- Authors: Gulsuner, S , Stein, D J , Susser, E S , Sibeko, G , Pretorius, A , Walsh, T , Majara, L , Mndini, M M , Mqulwana, S G , Ntola, O A , Casadei, S , Zingela, Zukiswa , Nagdee, M , Ramesar, R S , King, M-C , McClellan, J M , Ngqengelele, L L , Korchina, V , van der Merwe, C , Malan, M , Fader, K M , Feng, M , Willoughby, E , Munzi, D , Andrews, H F , Gur, R C , Gibbs, R A
- Date: 2020
- Subjects: Schizophrenia -- Diagnosis -- Cross-cultural studies , Medical genetics , Xhosa (African people)
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/4217 , vital:44044 , https://doi.org/10.1126/science.aay8833
- Description: Africa, the ancestral home of all modern humans, is the most informative continent for understanding the human genome and its contribution to complex disease. To better understand the genetics of schizophrenia, we studied the illness in the Xhosa population of South Africa, recruiting 909 cases and 917 age-, gender-, and residence-matched controls. Individuals with schizophrenia were significantly more likely than controls to harbor private, severely damaging mutations in genes that are critical to synaptic function, including neural circuitry mediated by the neurotransmitters glutamine, γ-aminobutyric acid, and dopamine. Schizophrenia is genetically highly heterogeneous, involving severe ultrarare mutations in genes that are critical to synaptic plasticity. The depth of genetic variation in Africa revealed this relationship with a moderate sample size and informed our understanding of the genetics of schizophrenia worldwide.
- Full Text:
- Date Issued: 2020