Orchid mycorrhizal and endophytic fungal diversity of three cooccurring terrestrial orchids in the large African genus Disa (Orchidaceae)
- Authors: Le Du, Bridgitte M
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/163363 , vital:41033
- Description: Thesis (MA)--Rhodes University, Faculty of Humanities, English Language and Linguistics, 2020.
- Full Text:
- Date Issued: 2020
- Authors: Le Du, Bridgitte M
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/163363 , vital:41033
- Description: Thesis (MA)--Rhodes University, Faculty of Humanities, English Language and Linguistics, 2020.
- Full Text:
- Date Issued: 2020
Paul Ashwin Transforming university education, a manifesto: A review
- Authors: McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185886 , vital:44445 , xlink:href="https://doi.org/10.1007/s10734-020-00641-z"
- Description: This book is wide-ranging in its focus. It tackles student-centeredness, graduate premiums, credentialing, quality assurance, big data and rankings, and yet it offers a coherent engagement with these and many other contemporary issues. The coherence is brought about by the consistent application of one central idea throughout the book. That is that the value of higher education for both the individual and for society is that it brings the graduate into a transformational relationship with knowledge that changes their sense of who they are and thereby makes possible their doing all number of things in the world.
- Full Text:
- Date Issued: 2020
- Authors: McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185886 , vital:44445 , xlink:href="https://doi.org/10.1007/s10734-020-00641-z"
- Description: This book is wide-ranging in its focus. It tackles student-centeredness, graduate premiums, credentialing, quality assurance, big data and rankings, and yet it offers a coherent engagement with these and many other contemporary issues. The coherence is brought about by the consistent application of one central idea throughout the book. That is that the value of higher education for both the individual and for society is that it brings the graduate into a transformational relationship with knowledge that changes their sense of who they are and thereby makes possible their doing all number of things in the world.
- Full Text:
- Date Issued: 2020
Perceived benefits of nature-based experiences as mediators of connectedness with nature: The case of Mystic Mountain
- Ward-Smith, Chesney, Naidoo, Tony, Olvitt, Lausanne L, Olvitt, Lausanne, Akhurst, Jacqueline
- Authors: Ward-Smith, Chesney , Naidoo, Tony , Olvitt, Lausanne L , Olvitt, Lausanne , Akhurst, Jacqueline
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372782 , vital:66622 , xlink:href="https://doi.org/10.1177/00812463209470"
- Description: Perceived nature disconnection lies at the heart of the world’s socio-ecological crisis. Finding ways to reconnect with nature is fundamental towards reducing the adverse psychological–social– ecological consequences of this disconnection. Understanding the psychological and social benefits of nature-based experiences is important towards actualising reconnection. This article discusses such benefits for child and adult participants from the Eastern Cape, South Africa. This work stems from Ecopsychology research with an outdoor education centre, Mystic Mountain. The experiences of two groups of children (n=25, aged 10–14years) and adult instructors (n=12, aged 18–50years) were explored using interpretive case-study methodology. Through semi-structured interviews and focus groups, participant observation, and reflexive journaling, data were collected and analysed thematically. This article centralises participants’ perceived psychological and social benefits of nature-based experiences as mediators of deeper self and nature connectedness. Integrating these benefits into nature-based pedagogy-design processes could contribute towards more effective enhancements of nature connectedness, and in turn, foster Earth’s larger flourishment.
- Full Text:
- Date Issued: 2020
- Authors: Ward-Smith, Chesney , Naidoo, Tony , Olvitt, Lausanne L , Olvitt, Lausanne , Akhurst, Jacqueline
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372782 , vital:66622 , xlink:href="https://doi.org/10.1177/00812463209470"
- Description: Perceived nature disconnection lies at the heart of the world’s socio-ecological crisis. Finding ways to reconnect with nature is fundamental towards reducing the adverse psychological–social– ecological consequences of this disconnection. Understanding the psychological and social benefits of nature-based experiences is important towards actualising reconnection. This article discusses such benefits for child and adult participants from the Eastern Cape, South Africa. This work stems from Ecopsychology research with an outdoor education centre, Mystic Mountain. The experiences of two groups of children (n=25, aged 10–14years) and adult instructors (n=12, aged 18–50years) were explored using interpretive case-study methodology. Through semi-structured interviews and focus groups, participant observation, and reflexive journaling, data were collected and analysed thematically. This article centralises participants’ perceived psychological and social benefits of nature-based experiences as mediators of deeper self and nature connectedness. Integrating these benefits into nature-based pedagogy-design processes could contribute towards more effective enhancements of nature connectedness, and in turn, foster Earth’s larger flourishment.
- Full Text:
- Date Issued: 2020
Photodynamic activity of 2, 6-diiodo-3, 5-dithienylvinyleneBODIPYs and their folate-functionalized chitosan-coated Pluronic® F-127 micelles on MCF-7 breast cancer cells
- Molupe, Nthabeleng, Babu, Balaji, Oluwole, David O, Prinsloo, Earl, Gai, Lizhi, Shen, Zhen, Mack, John, Nyokong, Tebello
- Authors: Molupe, Nthabeleng , Babu, Balaji , Oluwole, David O , Prinsloo, Earl , Gai, Lizhi , Shen, Zhen , Mack, John , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186222 , vital:44474 , xlink:href="https://doi.org/10.1142/S1088424619501773"
- Description: A 2,6-diiodo-3,5-dithienylvinyleneBODIPY dye was prepared and encapsulated with folate-chitosan capped Pluronic®® F-127 to provide drug delivery systems for photodynamic therapy (PDT). Moderately enhanced singlet oxygen quantum yields were observed for the dye encapsulation complexes in water. The in vitro dark cytotoxicity and photodynamic activity were investigated on the human breast adenocarcinoma (MCF-7) cell line. Minimal dark cytotoxicity was observed for the BODIPY dyes in 5% DMSO and when encapsulated in folate-functionalized chitosan-coated Pluronic®® F-127 micelles, since the cell viability values are consistently greater than 80% over the 0-40 μg⋅mL−1μg⋅mL−1 concentration range. Upon irradiation of the samples, significant cytocidal activity was observed for the encapsulation complex of a 2,6-diiodo-8-dimethylaminophenyl-3,5-dithienylvinyleneBODIPY dye with less than 50% viable cells observed at concentrations ≥20μg⋅mL−1≥20μg⋅mL−1.
- Full Text:
- Date Issued: 2020
- Authors: Molupe, Nthabeleng , Babu, Balaji , Oluwole, David O , Prinsloo, Earl , Gai, Lizhi , Shen, Zhen , Mack, John , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186222 , vital:44474 , xlink:href="https://doi.org/10.1142/S1088424619501773"
- Description: A 2,6-diiodo-3,5-dithienylvinyleneBODIPY dye was prepared and encapsulated with folate-chitosan capped Pluronic®® F-127 to provide drug delivery systems for photodynamic therapy (PDT). Moderately enhanced singlet oxygen quantum yields were observed for the dye encapsulation complexes in water. The in vitro dark cytotoxicity and photodynamic activity were investigated on the human breast adenocarcinoma (MCF-7) cell line. Minimal dark cytotoxicity was observed for the BODIPY dyes in 5% DMSO and when encapsulated in folate-functionalized chitosan-coated Pluronic®® F-127 micelles, since the cell viability values are consistently greater than 80% over the 0-40 μg⋅mL−1μg⋅mL−1 concentration range. Upon irradiation of the samples, significant cytocidal activity was observed for the encapsulation complex of a 2,6-diiodo-8-dimethylaminophenyl-3,5-dithienylvinyleneBODIPY dye with less than 50% viable cells observed at concentrations ≥20μg⋅mL−1≥20μg⋅mL−1.
- Full Text:
- Date Issued: 2020
Photodynamic antimicrobial chemotherapy of a dimethylamino-functionalized asymmetric zinc (II) phthalocyanine and its quaternized derivative against Staphylococcus aureus when supported on asymmetric polystyrene polymer membranes
- Mafukidze, Donovan M, Nyokong, Tebello
- Authors: Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186168 , vital:44470 , xlink:href="https://doi.org/10.1016/j.reactfunctpolym.2020.104634"
- Description: Membrane applications are hindered by fouling. Photoactive membranes (containing photosensitizers) show photodynamic antimicrobial chemotherapy (PACT) activity which reduces biological fouling. In this work we use phthalocyanines (Pcs) as photosensitizers. The Pcs used are: 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(dimethylamino) phthalocyaninato zinc(II) (1) and the quaternized 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(trimethylamino) phthalocyanine zinc(II) methyl sulfate (2). Complex 2 showed an enhanced singlet oxygen quantum yield (ΦΔ) of 0.76 compared to 0.53 for 1. Complex 2 showed enhanced PACT activity against Staphylococcus aureus giving a log reduction value of 9.4, while its precursor (complex 1) gave 0.08. The complexes were then conjugated to amine-functionalized polystyrene and embedded into polystyrene to form membranes resulting in ΦΔ values of 0.24 and 0.27 for complexes 1 and 2 respectively in water. The latter membrane showed better PACT activity.
- Full Text:
- Date Issued: 2020
- Authors: Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186168 , vital:44470 , xlink:href="https://doi.org/10.1016/j.reactfunctpolym.2020.104634"
- Description: Membrane applications are hindered by fouling. Photoactive membranes (containing photosensitizers) show photodynamic antimicrobial chemotherapy (PACT) activity which reduces biological fouling. In this work we use phthalocyanines (Pcs) as photosensitizers. The Pcs used are: 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(dimethylamino) phthalocyaninato zinc(II) (1) and the quaternized 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(trimethylamino) phthalocyanine zinc(II) methyl sulfate (2). Complex 2 showed an enhanced singlet oxygen quantum yield (ΦΔ) of 0.76 compared to 0.53 for 1. Complex 2 showed enhanced PACT activity against Staphylococcus aureus giving a log reduction value of 9.4, while its precursor (complex 1) gave 0.08. The complexes were then conjugated to amine-functionalized polystyrene and embedded into polystyrene to form membranes resulting in ΦΔ values of 0.24 and 0.27 for complexes 1 and 2 respectively in water. The latter membrane showed better PACT activity.
- Full Text:
- Date Issued: 2020
Photodynamic antimicrobial chemotherapy of asymmetric porphyrin-silver conjugates towards photoinactivation of Staphylococcus aureus
- Shabangu, Samuel M, Babu, Balaji, Soy, Rodah C, Managa, Muthumuni, Sekhosana, Kutloano E, Nyokong, Tebello
- Authors: Shabangu, Samuel M , Babu, Balaji , Soy, Rodah C , Managa, Muthumuni , Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186536 , vital:44509 , xlink:href="https://doi.org/10.1080/00958972.2020.1739273"
- Description: Asymmetric mono-carboxy-porphyrins, (5-(4-carboxyphenyl)10,15, 20-tris(pentafluorophenyl)porphyrinato zinc(II) (1), 5-(4- carboxyphenyl)10,15,20-triphenylporphyrinato zinc(II) (2) and 5-(4- carboxyphenyl)10,15,20-tris(2-thienyl)porphyrinato zinc(II) (3), were linked to Ag nanoparticles (AgNPs) through amide bonds and selfassembly (the latter only for 3). The porphyrins and conjugates were used for photodynamic antimicrobial chemotherapy (PACT) against Staphylococcus aureus. PACT uses singlet oxygen for antimicrobial activity. Complex 3 and its conjugates had higher singlet oxygen quantum yields and higher log reduction when compared with the rest of the porphyrins and corresponding conjugates. These high log reductions for 3 and its conjugate were attributed to the presence of sulfur groups whereby there was more interaction with the bacterial membrane.
- Full Text:
- Date Issued: 2020
- Authors: Shabangu, Samuel M , Babu, Balaji , Soy, Rodah C , Managa, Muthumuni , Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186536 , vital:44509 , xlink:href="https://doi.org/10.1080/00958972.2020.1739273"
- Description: Asymmetric mono-carboxy-porphyrins, (5-(4-carboxyphenyl)10,15, 20-tris(pentafluorophenyl)porphyrinato zinc(II) (1), 5-(4- carboxyphenyl)10,15,20-triphenylporphyrinato zinc(II) (2) and 5-(4- carboxyphenyl)10,15,20-tris(2-thienyl)porphyrinato zinc(II) (3), were linked to Ag nanoparticles (AgNPs) through amide bonds and selfassembly (the latter only for 3). The porphyrins and conjugates were used for photodynamic antimicrobial chemotherapy (PACT) against Staphylococcus aureus. PACT uses singlet oxygen for antimicrobial activity. Complex 3 and its conjugates had higher singlet oxygen quantum yields and higher log reduction when compared with the rest of the porphyrins and corresponding conjugates. These high log reductions for 3 and its conjugate were attributed to the presence of sulfur groups whereby there was more interaction with the bacterial membrane.
- Full Text:
- Date Issued: 2020
Photophysical and nonlinear optical properties of the positional isomers of 4-(4-tertbutylphenoxy) substituted cobalt, nickel and copper phthalocyanines
- Neduvhuledza, Zelda, Nkaki, Thabo, Louzada, Marcel, Nyokong, Tebello, Khene, Samson M
- Authors: Neduvhuledza, Zelda , Nkaki, Thabo , Louzada, Marcel , Nyokong, Tebello , Khene, Samson M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186067 , vital:44460 , xlink:href="https://doi.org/10.1016/j.optmat.2020.110195"
- Description: This paper reports on the third order nonlinear optical properties of cobalt, nickel and tetrakis(4- terbutylphenoxy)phthalocyaninatocopper(II) isomers, using the Z-scan technique. Metal-free isomers were found to have high nonlinear absorption coefficient (β) values compared to the metalated isomers. Metal-free C2v isomer was found to have the highest β value of 1.52 × 10− 10 mMW− 1 in THF. All the metal-free and metal phthalocyanine isomers nonlinear properties were found to be dependent on the singlet state absorption. Imaginary second order nonlinear hyperpolarizability (Im[γ]), ground state cross section (σg), excited states cross sections (σs and σt) and two photon absorption (TPA) cross section (σTPA) values are reported in this work. The five-energy level model rate equations were used to model the nonlinear response and absorption cross sections.
- Full Text:
- Date Issued: 2020
- Authors: Neduvhuledza, Zelda , Nkaki, Thabo , Louzada, Marcel , Nyokong, Tebello , Khene, Samson M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186067 , vital:44460 , xlink:href="https://doi.org/10.1016/j.optmat.2020.110195"
- Description: This paper reports on the third order nonlinear optical properties of cobalt, nickel and tetrakis(4- terbutylphenoxy)phthalocyaninatocopper(II) isomers, using the Z-scan technique. Metal-free isomers were found to have high nonlinear absorption coefficient (β) values compared to the metalated isomers. Metal-free C2v isomer was found to have the highest β value of 1.52 × 10− 10 mMW− 1 in THF. All the metal-free and metal phthalocyanine isomers nonlinear properties were found to be dependent on the singlet state absorption. Imaginary second order nonlinear hyperpolarizability (Im[γ]), ground state cross section (σg), excited states cross sections (σs and σt) and two photon absorption (TPA) cross section (σTPA) values are reported in this work. The five-energy level model rate equations were used to model the nonlinear response and absorption cross sections.
- Full Text:
- Date Issued: 2020
Photophysico-chemical properties and photoinactivation of Staphylococcus Aureus using zinc phthalocyanines linked silver nanoparticles conjugates
- Matlou, Gauta G, Nyokong, Tebello
- Authors: Matlou, Gauta G , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186278 , vital:44481 , xlink:href="https://doi.org/10.1016/j.dyepig.2020.108237"
- Description: The synthesis of zinc (II) tri (tert-butyl phenoxy) mono cinnamic acid Pc (complex 1) is reported for the first time in this work. Complex 1 and the reported zinc (II) tri (tert-butyl), mono cinnamic acid phthalocyanine (2), zinc (II) mono cinnamic acid substituted phthalocyanine (3) and zinc (II) tetra cinnamic acid substituted phthalocyanine (4) are conjugated to cysteine capped silver nanoparticles (cys-AgNPs) through an amide bond. The photophysicochemical properties and the photodynamic antimicrobial chemotherapy (PACT) activities of the Pc-cys-AgNPs conjugates and the Pcs alone on S. Aureus are reported. Improved triplet and singlet oxygen quantum yields were observed for the conjugated complexes compared to Pcs alone, due to the heavy atom effect of cys-AgNPs. Asymmetric complexes 1,2, 3 and their respective conjugates recorded higher photosensitizing properties and PACT activities compared to 4 and 4-cys-AgNPs, respectively. Higher log reductions and percentage reductions of S. Aureus were recorded for conjugated complexes compared to ZnPcs only, showing enhanced PACT activities due to their higher singlet oxygen quantum yields.
- Full Text:
- Date Issued: 2020
- Authors: Matlou, Gauta G , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186278 , vital:44481 , xlink:href="https://doi.org/10.1016/j.dyepig.2020.108237"
- Description: The synthesis of zinc (II) tri (tert-butyl phenoxy) mono cinnamic acid Pc (complex 1) is reported for the first time in this work. Complex 1 and the reported zinc (II) tri (tert-butyl), mono cinnamic acid phthalocyanine (2), zinc (II) mono cinnamic acid substituted phthalocyanine (3) and zinc (II) tetra cinnamic acid substituted phthalocyanine (4) are conjugated to cysteine capped silver nanoparticles (cys-AgNPs) through an amide bond. The photophysicochemical properties and the photodynamic antimicrobial chemotherapy (PACT) activities of the Pc-cys-AgNPs conjugates and the Pcs alone on S. Aureus are reported. Improved triplet and singlet oxygen quantum yields were observed for the conjugated complexes compared to Pcs alone, due to the heavy atom effect of cys-AgNPs. Asymmetric complexes 1,2, 3 and their respective conjugates recorded higher photosensitizing properties and PACT activities compared to 4 and 4-cys-AgNPs, respectively. Higher log reductions and percentage reductions of S. Aureus were recorded for conjugated complexes compared to ZnPcs only, showing enhanced PACT activities due to their higher singlet oxygen quantum yields.
- Full Text:
- Date Issued: 2020
Plant-Based Synthesis of Silver Nanoparticles Using Aqueous Leaf Extract of Salvia officinalis: Characterization and its Antiplasmodial Activity
- Okaiyeto, Kunle, Hoppe, Heinrich C, Okoh, Anthony I
- Authors: Okaiyeto, Kunle , Hoppe, Heinrich C , Okoh, Anthony I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429472 , vital:72613 , xlink:href="https://doi.org/10.1007/s10876-020-01766-y"
- Description: In the present study, an aqueous leaf extract of Salvia officinalis was used to synthesize silver nanoparticles (AgNPs) and characterized with different techniques such as UV–vis spectroscopy, Fourier transform infrared (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive X-ray spectroscopy (EDX), Transmission electron microscope (TEM) and thermogravimetric analysis (TGA). Subsequently, its cytotoxic effect against human cervix adenocarcinoma (HeLa) cells and antiplasmodial activity against Plasmodium falciparum were investigated. UV–vis spectrum of AgNPs displayed an absorption peak at 323 nm and TEM result revealed it to be spherical in shape with average size of 41 nm. FTIR results highlighted the key bioactive compounds that could be responsible for the reduction and capping of AgNPs and XRD analysis showed its crystalline nature with a face-centered cubic (fcc) structure. The synthesized AgNPs was found to be less cytotoxic against HeLa cells line and demonstrated good antiplasmodial potential (IC50 = 3.6 µg/mL). Findings from this study indicated that the AgNPs could serve as a template in the development of new drugs for the control of malaria and hence, further study is needed to identify and characterize the potent molecules that suppress the malaria parasite.
- Full Text:
- Date Issued: 2020
- Authors: Okaiyeto, Kunle , Hoppe, Heinrich C , Okoh, Anthony I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429472 , vital:72613 , xlink:href="https://doi.org/10.1007/s10876-020-01766-y"
- Description: In the present study, an aqueous leaf extract of Salvia officinalis was used to synthesize silver nanoparticles (AgNPs) and characterized with different techniques such as UV–vis spectroscopy, Fourier transform infrared (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive X-ray spectroscopy (EDX), Transmission electron microscope (TEM) and thermogravimetric analysis (TGA). Subsequently, its cytotoxic effect against human cervix adenocarcinoma (HeLa) cells and antiplasmodial activity against Plasmodium falciparum were investigated. UV–vis spectrum of AgNPs displayed an absorption peak at 323 nm and TEM result revealed it to be spherical in shape with average size of 41 nm. FTIR results highlighted the key bioactive compounds that could be responsible for the reduction and capping of AgNPs and XRD analysis showed its crystalline nature with a face-centered cubic (fcc) structure. The synthesized AgNPs was found to be less cytotoxic against HeLa cells line and demonstrated good antiplasmodial potential (IC50 = 3.6 µg/mL). Findings from this study indicated that the AgNPs could serve as a template in the development of new drugs for the control of malaria and hence, further study is needed to identify and characterize the potent molecules that suppress the malaria parasite.
- Full Text:
- Date Issued: 2020
Preformulation studies of efavirenz with lipid excipients using thermal and spectroscopic techniques
- Makoni, Pedzisai A, Kasongo, Kasongo W, Walker, Roderick B
- Authors: Makoni, Pedzisai A , Kasongo, Kasongo W , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183253 , vital:43934 , xlink:href=" https://doi.org/10.1691/ph.2020.0053"
- Description: Investigation and identification of potential lipids for the manufacture of efavirenz loaded solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) was undertaken. Polymorphic modification and characteristics of the lipids with the best solubilising potential for efavirenz was explored using Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC) and Wide-angle X-ray Scattering (WAXS). Lipid screening revealed that EFV is highly soluble in solid and liquid lipids, with glyceryl monostearate (GM) and Transcutol® HP (THP) exhibiting the best solubilising potential for EFV. GM exists in a stable β-polymorphic modification prior to exposure to heat, but exists in an α-polymorphic modification following exposure to heat. However, it was established that the addition of THP to GM revealed the co-existence of the α- and β'-polymorphic modifications of the lipid. EFV (60% w/w) exists in a crystalline state in a 70:30 mixture of GM and THP. Investigation of binary mixtures of EFV/GM and GM/THP, in addition to eutectic mixtures of EFV, GM and THP using FT-IR, DSC and WAXS revealed no potential interactions between EFV and the lipids selected for the production of the nanocarriers.
- Full Text:
- Date Issued: 2020
Preformulation studies of efavirenz with lipid excipients using thermal and spectroscopic techniques
- Authors: Makoni, Pedzisai A , Kasongo, Kasongo W , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183253 , vital:43934 , xlink:href=" https://doi.org/10.1691/ph.2020.0053"
- Description: Investigation and identification of potential lipids for the manufacture of efavirenz loaded solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) was undertaken. Polymorphic modification and characteristics of the lipids with the best solubilising potential for efavirenz was explored using Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC) and Wide-angle X-ray Scattering (WAXS). Lipid screening revealed that EFV is highly soluble in solid and liquid lipids, with glyceryl monostearate (GM) and Transcutol® HP (THP) exhibiting the best solubilising potential for EFV. GM exists in a stable β-polymorphic modification prior to exposure to heat, but exists in an α-polymorphic modification following exposure to heat. However, it was established that the addition of THP to GM revealed the co-existence of the α- and β'-polymorphic modifications of the lipid. EFV (60% w/w) exists in a crystalline state in a 70:30 mixture of GM and THP. Investigation of binary mixtures of EFV/GM and GM/THP, in addition to eutectic mixtures of EFV, GM and THP using FT-IR, DSC and WAXS revealed no potential interactions between EFV and the lipids selected for the production of the nanocarriers.
- Full Text:
- Date Issued: 2020
Prioritising African perspectives in psychiatric genomics research
- Kamaara, Eunice, Kong, Camillia, Campbell, Megan
- Authors: Kamaara, Eunice , Kong, Camillia , Campbell, Megan
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302520 , vital:58204 , xlink:href="https://doi.org/10.1111/dewb.12248"
- Description: Psychiatric genomics research with African populations comes with a range of practical challenges around translation of psychiatric genomics research concepts, procedures, and nosology. These challenges raise deep ethical issues particularly around legitimacy of informed consent, a core foundation of research ethics. Through aconsideration of the constitutive function of language, the paper problematises like‐for‐like, designative translations which often involve the ‘indigenization’ of English terms or use of metaphors which misrepresent the risks and benefits of research. This paper argues that effective translation of psychiatric genomics research terminology in African contexts demands substantive engagement with African conceptual schemas and values. In developing attenuated forms of translational thinking, researchers may recognise the deeper motivational reasons behind participation in research, highlighting the possibility that such reasons may depart from the original meaning implied within informed consent forms. These translational issues might be ameliorated with a critical re-examination of how researchers develop and present protocols to institutional ethics review boards.
- Full Text:
- Date Issued: 2020
- Authors: Kamaara, Eunice , Kong, Camillia , Campbell, Megan
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302520 , vital:58204 , xlink:href="https://doi.org/10.1111/dewb.12248"
- Description: Psychiatric genomics research with African populations comes with a range of practical challenges around translation of psychiatric genomics research concepts, procedures, and nosology. These challenges raise deep ethical issues particularly around legitimacy of informed consent, a core foundation of research ethics. Through aconsideration of the constitutive function of language, the paper problematises like‐for‐like, designative translations which often involve the ‘indigenization’ of English terms or use of metaphors which misrepresent the risks and benefits of research. This paper argues that effective translation of psychiatric genomics research terminology in African contexts demands substantive engagement with African conceptual schemas and values. In developing attenuated forms of translational thinking, researchers may recognise the deeper motivational reasons behind participation in research, highlighting the possibility that such reasons may depart from the original meaning implied within informed consent forms. These translational issues might be ameliorated with a critical re-examination of how researchers develop and present protocols to institutional ethics review boards.
- Full Text:
- Date Issued: 2020
Production, purification and characterization of a multifunctional, thermostable and acido/alkaline stable putative xylanase from the psychrotrophic bacterium, Sphingomonas aerolata
- Authors: Mathibe, Brian Nkanyiso
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164478 , vital:41122
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
- Authors: Mathibe, Brian Nkanyiso
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164478 , vital:41122
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
Prospects for the biological control of Iris pseudacorus L(Iridaceae)
- Minuti, Gianmarco, Coetzee, Julie A, Ngxande-Koza, Samella W, Hill, Martin P, Stiers, Iris
- Authors: Minuti, Gianmarco , Coetzee, Julie A , Ngxande-Koza, Samella W , Hill, Martin P , Stiers, Iris
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417776 , vital:71485 , xlink:href="https://doi.org/10.1080/09583157.2020.1853050"
- Description: Native to Europe, North Africa and western Asia, Iris pseudacorus L. (Iridaceae) has invaded natural and human-modified wetlands worldwide. This species is considered a noxious weed in several countries including Argentina, South Africa and New Zealand. Its broad ecological tolerance, high resilience and reproductive potential make current mechanical and chemical control measures cost-ineffective, and biological control is considered a suitable alternative. In order to prioritise candidate biocontrol agents, a list of organisms reported to attack the plant within its native range has been assembled, and information about their host-range and damaging potential gathered from the literature. Furthermore, surveys for natural enemies of the plant were conducted in Belgium and northern Italy. The insect fauna associated with I. pseudacorus at the sites surveyed comprised mostly incidental visitors and polyphagous feeders, with the exception of the sawfly Rhadinoceraea micans Klug (Hymenoptera: Tenthredinidae), the seed weevil Mononychus punctumalbum Herbst (Coleoptera: Curculionidae), and the flea beetle Aphthona nonstriata Goeze (Coleoptera: Chrysomelidae). The potential of these species for biocontrol was evaluated, and A. nonstriata was given highest priority. A population of this species was imported to quarantine in South Africa, where it is currently undergoing host-specificity testing. Importation of the two remaining candidates is expected shortly. In conclusion, the prospects for the biological control of I. pseudacorus appear promising.
- Full Text:
- Date Issued: 2020
- Authors: Minuti, Gianmarco , Coetzee, Julie A , Ngxande-Koza, Samella W , Hill, Martin P , Stiers, Iris
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417776 , vital:71485 , xlink:href="https://doi.org/10.1080/09583157.2020.1853050"
- Description: Native to Europe, North Africa and western Asia, Iris pseudacorus L. (Iridaceae) has invaded natural and human-modified wetlands worldwide. This species is considered a noxious weed in several countries including Argentina, South Africa and New Zealand. Its broad ecological tolerance, high resilience and reproductive potential make current mechanical and chemical control measures cost-ineffective, and biological control is considered a suitable alternative. In order to prioritise candidate biocontrol agents, a list of organisms reported to attack the plant within its native range has been assembled, and information about their host-range and damaging potential gathered from the literature. Furthermore, surveys for natural enemies of the plant were conducted in Belgium and northern Italy. The insect fauna associated with I. pseudacorus at the sites surveyed comprised mostly incidental visitors and polyphagous feeders, with the exception of the sawfly Rhadinoceraea micans Klug (Hymenoptera: Tenthredinidae), the seed weevil Mononychus punctumalbum Herbst (Coleoptera: Curculionidae), and the flea beetle Aphthona nonstriata Goeze (Coleoptera: Chrysomelidae). The potential of these species for biocontrol was evaluated, and A. nonstriata was given highest priority. A population of this species was imported to quarantine in South Africa, where it is currently undergoing host-specificity testing. Importation of the two remaining candidates is expected shortly. In conclusion, the prospects for the biological control of I. pseudacorus appear promising.
- Full Text:
- Date Issued: 2020
Rational design and regioselective synthesis of conformationally restricted furan-derived ligands as potential anti-malarial agents
- Mutorwa, Marius K, Nokalipa, Iviwe, Tanner, Delia C, Blatch, Gregory L, Lobb, Kevin A, Klein, Rosalyn, Kaye, Perry T
- Authors: Mutorwa, Marius K , Nokalipa, Iviwe , Tanner, Delia C , Blatch, Gregory L , Lobb, Kevin A , Klein, Rosalyn , Kaye, Perry T
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447170 , vital:74589 , xlink:href="https://doi.org/10.24820/ark.5550190.p011.281"
- Description: Substituted 3-furanomethyl phosphate esters and their corresponding phosphoric acids have been prepared as conformationally restricted analogues of DOXP, the natural substrate for Plasmodium falciparum 1-deoxyD-xylulose-5-phosphate reductoisomerase (PfDXR), and fosmidomycin, an established inhibitor. Saturation Transfer Difference (STD) NMR analysis and in silico docking data suggest the potential of such compounds as PfDXR inhibitors.
- Full Text:
- Date Issued: 2020
- Authors: Mutorwa, Marius K , Nokalipa, Iviwe , Tanner, Delia C , Blatch, Gregory L , Lobb, Kevin A , Klein, Rosalyn , Kaye, Perry T
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447170 , vital:74589 , xlink:href="https://doi.org/10.24820/ark.5550190.p011.281"
- Description: Substituted 3-furanomethyl phosphate esters and their corresponding phosphoric acids have been prepared as conformationally restricted analogues of DOXP, the natural substrate for Plasmodium falciparum 1-deoxyD-xylulose-5-phosphate reductoisomerase (PfDXR), and fosmidomycin, an established inhibitor. Saturation Transfer Difference (STD) NMR analysis and in silico docking data suggest the potential of such compounds as PfDXR inhibitors.
- Full Text:
- Date Issued: 2020
Reimagining academic identities in response to research demands at Universities of Technology
- Gumbi, Thobani, McKenna, Sioux
- Authors: Gumbi, Thobani , McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185897 , vital:44446 , xlink:href="https://doi.org/10.14426/cristal.v8i1.234"
- Description: In the last volume of this journal, Garraway and Winberg called for a reimagination of Universities of Technology (UoT) within the South African higher education system. This article continues that conversation by looking at the implications that the formation of the UoT had for academics’ identities. Technikon lecturers’ identities were closely tied to workplace expertise, but demands for research in UoTs have changed this. A social realist analysis of interviews with fifteen academics at three UoTs finds that research remains a contested issue. Interviewees understood research to take the form of acquiring postgraduate qualifications, rather than as an ongoing activity tied to their identities. Echoing Garraway and Winberg’s study, the bureaucratic nature of the institutional culture was referred to as a constraint. There was also a view that for this programme, Dental Technology, a demand for research was needed from industry if this was to be a valued aspect of academics’ identities.
- Full Text:
- Date Issued: 2020
- Authors: Gumbi, Thobani , McKenna, Sioux
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185897 , vital:44446 , xlink:href="https://doi.org/10.14426/cristal.v8i1.234"
- Description: In the last volume of this journal, Garraway and Winberg called for a reimagination of Universities of Technology (UoT) within the South African higher education system. This article continues that conversation by looking at the implications that the formation of the UoT had for academics’ identities. Technikon lecturers’ identities were closely tied to workplace expertise, but demands for research in UoTs have changed this. A social realist analysis of interviews with fifteen academics at three UoTs finds that research remains a contested issue. Interviewees understood research to take the form of acquiring postgraduate qualifications, rather than as an ongoing activity tied to their identities. Echoing Garraway and Winberg’s study, the bureaucratic nature of the institutional culture was referred to as a constraint. There was also a view that for this programme, Dental Technology, a demand for research was needed from industry if this was to be a valued aspect of academics’ identities.
- Full Text:
- Date Issued: 2020
Relational hubs for collaborative landscape stewardship
- Cockburn, Jessica J, Cundill, Georgina, Shackleton, Sheona, Cele, Ayanda, Cornelius, Susanna F, Koopman, Vaughan, Le Roux, Jean-Pierre, McLeod, Nicky, Rouget, Mathieu, Schroder, Samantha, Van den Broek, Dieter, Wright, Dale R, Zwinkelse, Marijn
- Authors: Cockburn, Jessica J , Cundill, Georgina , Shackleton, Sheona , Cele, Ayanda , Cornelius, Susanna F , Koopman, Vaughan , Le Roux, Jean-Pierre , McLeod, Nicky , Rouget, Mathieu , Schroder, Samantha , Van den Broek, Dieter , Wright, Dale R , Zwinkelse, Marijn
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392748 , vital:68789 , xlink:href="https://doi.org/10.1080/08941920.2019.1658141"
- Description: Landscape stewardship is considered an important place-based approach to addressing sustainability challenges. Working at landscape-level requires collaboration between diverse landscape stakeholders. In this study, we partnered with local stewardship practitioners across six cases in South Africa to investigate how they facilitate collaboration towards social-ecological sustainability outcomes. We found that practitioners facilitate collaboration among stakeholders by operating as relational hubs in the landscape. Through these hubs, they build new inter-personal relationships among stakeholders, creating social networks which enable stewardship practice. The hubs deepen human-nature relationships by creating enabling conditions for stewards to put stewardship ethics into action. Drawing on insights from these cases, we call for a relational approach to landscape stewardship which focuses on human-to-human and human-to-nature relationships. Moreover, we argue that landscape stewardship initiatives need to re-focus stewardship on stewards, recognizing them as key agents of change in addressing the conflict between agriculture and conservation inherent in many landscapes.
- Full Text:
- Date Issued: 2020
- Authors: Cockburn, Jessica J , Cundill, Georgina , Shackleton, Sheona , Cele, Ayanda , Cornelius, Susanna F , Koopman, Vaughan , Le Roux, Jean-Pierre , McLeod, Nicky , Rouget, Mathieu , Schroder, Samantha , Van den Broek, Dieter , Wright, Dale R , Zwinkelse, Marijn
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392748 , vital:68789 , xlink:href="https://doi.org/10.1080/08941920.2019.1658141"
- Description: Landscape stewardship is considered an important place-based approach to addressing sustainability challenges. Working at landscape-level requires collaboration between diverse landscape stakeholders. In this study, we partnered with local stewardship practitioners across six cases in South Africa to investigate how they facilitate collaboration towards social-ecological sustainability outcomes. We found that practitioners facilitate collaboration among stakeholders by operating as relational hubs in the landscape. Through these hubs, they build new inter-personal relationships among stakeholders, creating social networks which enable stewardship practice. The hubs deepen human-nature relationships by creating enabling conditions for stewards to put stewardship ethics into action. Drawing on insights from these cases, we call for a relational approach to landscape stewardship which focuses on human-to-human and human-to-nature relationships. Moreover, we argue that landscape stewardship initiatives need to re-focus stewardship on stewards, recognizing them as key agents of change in addressing the conflict between agriculture and conservation inherent in many landscapes.
- Full Text:
- Date Issued: 2020
Repurposing a polymer precursor scaffold for medicinal application: Synthesis, characterization and biological evaluation of ferrocenyl 1,3-benzoxazine derivatives as potential antiprotozoal and anticancer agents
- Authors: Mbaba, Mziyanda
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164502 , vital:41124 , DOI 10.21504/10962/164502
- Description: The benzoxazines are a prominent class of heterocyclic compounds that possess a multitude of properties. To this end, benzoxazine derivatives have been used as versatile compounds for various utilities ranging from biological applications to the fabrication of polymers. Particularly, the 1,3-benzoxazine scaffold has featured in several bioactive compounds showing antimalarial, anticancer and antibacterial activities. Traditionally, it has been employed as a substrate in the synthesis of polymers with appealing physical and chemical properties. Due to the increasing interest in the polymer application of 1,3-benzoxazines, research of the 1,3-benzoxazine motif for polymer synthesis has been prioritized over other applications including its medicinal potential. The continuous development of resistance to clinical anticancer and antimalarial drugs has necessitated the need for the search of innovative bioactive compounds as potential alternative medicinal agents. To address this, the field of medicinal chemistry is adapting new approaches to counter resistance by incorporating nonconventional chemical moieties such as organometallic complexes, like ferrocene, into bioactive chemical motifs to serve as novel compounds with medicinal benefits. Incorporation of ferrocene into known bioactive chemical moieties has been shown to impart beneficial biological effects into the resultant compounds, which include the introduction of novel, and sometimes varied, mechanistic modalities and enhanced potency. Presented with the benefits of this strategy, the current work aims to design and evaluate the pharmaceutical capacity of novel derivatives containing 1,3-benzoxazine scaffold (traditionally applied in polymer synthesis) hybridized with the organometallic ferrocene unit as bioactive agents. Using a combination of expedient synthetic procedures such as the Burke three-component Mannich-type condensation, Vilsmeier-Haack formylation and reductive amination, four series of ferrocenyl 1,3-benzoxazine derivatives were synthesized and their structures confirmed by common spectroscopic techniques: nuclear magnetic resonance (NMR), infrared spectroscopy (IR) and high-resolution mass spectrometry (HRMS). The target compounds were evaluated in vitro for potential antimalarial and anticancer activities against strains of the malaria parasite (Plasmodium falciparum 3D7 and Dd2) and the triple-negative breast cancer cell line HCC70. Compounds exhibited higher potency towards the Plasmodium falciparum strains with IC50 values in the low and sub-micromolar range in comparison to the breast cancer cell line against for which mid-molar activities were observed. To gain insight into the possible mode of action of ferrocenyl 1,3-benzoxazines, representative compounds showing most efficacy from each series were assessed for DNA binding affinity by employing UV-Vis and fluorescence DNA titration experiments. The selected compounds were found to interact with the DNA by binding to the minor groove, and these findings were confirmed by in silico ligand docking studies using a B-DNA structure as the receptor. Compound 3.16c (IC50: 0.261 μM [3D7], 0.599 μM [Dd2], 11.0 μM [HCC70]), which emerged as the most promising compound, was found to induce DNA damage in HCC70 cancer cells when investigated for effects of DNA interaction. Additionally, compound 3.16c displayed a higher binding constant (Kb) against DNA isolated from 3D7 Plasmodium falciparum trophozoites (Kb = 1.88×106 M-1) than the mammalian DNA (Kb = 6.33×104 M-1) from calf thymus, thus explaining the preferred selectivity of the compounds for the malaria parasite. Moreover, the investigated compounds demonstrated binding affinity for synthetic hemozoin, β-hematin. Collectively, these data suggest that the compounds possess a dual mode of action for antimalarial activity involving DNA interaction and hemozoin inhibition. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2020
- Authors: Mbaba, Mziyanda
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164502 , vital:41124 , DOI 10.21504/10962/164502
- Description: The benzoxazines are a prominent class of heterocyclic compounds that possess a multitude of properties. To this end, benzoxazine derivatives have been used as versatile compounds for various utilities ranging from biological applications to the fabrication of polymers. Particularly, the 1,3-benzoxazine scaffold has featured in several bioactive compounds showing antimalarial, anticancer and antibacterial activities. Traditionally, it has been employed as a substrate in the synthesis of polymers with appealing physical and chemical properties. Due to the increasing interest in the polymer application of 1,3-benzoxazines, research of the 1,3-benzoxazine motif for polymer synthesis has been prioritized over other applications including its medicinal potential. The continuous development of resistance to clinical anticancer and antimalarial drugs has necessitated the need for the search of innovative bioactive compounds as potential alternative medicinal agents. To address this, the field of medicinal chemistry is adapting new approaches to counter resistance by incorporating nonconventional chemical moieties such as organometallic complexes, like ferrocene, into bioactive chemical motifs to serve as novel compounds with medicinal benefits. Incorporation of ferrocene into known bioactive chemical moieties has been shown to impart beneficial biological effects into the resultant compounds, which include the introduction of novel, and sometimes varied, mechanistic modalities and enhanced potency. Presented with the benefits of this strategy, the current work aims to design and evaluate the pharmaceutical capacity of novel derivatives containing 1,3-benzoxazine scaffold (traditionally applied in polymer synthesis) hybridized with the organometallic ferrocene unit as bioactive agents. Using a combination of expedient synthetic procedures such as the Burke three-component Mannich-type condensation, Vilsmeier-Haack formylation and reductive amination, four series of ferrocenyl 1,3-benzoxazine derivatives were synthesized and their structures confirmed by common spectroscopic techniques: nuclear magnetic resonance (NMR), infrared spectroscopy (IR) and high-resolution mass spectrometry (HRMS). The target compounds were evaluated in vitro for potential antimalarial and anticancer activities against strains of the malaria parasite (Plasmodium falciparum 3D7 and Dd2) and the triple-negative breast cancer cell line HCC70. Compounds exhibited higher potency towards the Plasmodium falciparum strains with IC50 values in the low and sub-micromolar range in comparison to the breast cancer cell line against for which mid-molar activities were observed. To gain insight into the possible mode of action of ferrocenyl 1,3-benzoxazines, representative compounds showing most efficacy from each series were assessed for DNA binding affinity by employing UV-Vis and fluorescence DNA titration experiments. The selected compounds were found to interact with the DNA by binding to the minor groove, and these findings were confirmed by in silico ligand docking studies using a B-DNA structure as the receptor. Compound 3.16c (IC50: 0.261 μM [3D7], 0.599 μM [Dd2], 11.0 μM [HCC70]), which emerged as the most promising compound, was found to induce DNA damage in HCC70 cancer cells when investigated for effects of DNA interaction. Additionally, compound 3.16c displayed a higher binding constant (Kb) against DNA isolated from 3D7 Plasmodium falciparum trophozoites (Kb = 1.88×106 M-1) than the mammalian DNA (Kb = 6.33×104 M-1) from calf thymus, thus explaining the preferred selectivity of the compounds for the malaria parasite. Moreover, the investigated compounds demonstrated binding affinity for synthetic hemozoin, β-hematin. Collectively, these data suggest that the compounds possess a dual mode of action for antimalarial activity involving DNA interaction and hemozoin inhibition. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2020
Resisting abortion stigma in situ: South African womxn's and healthcare providers' accounts of the pre-abortion counselling healthcare encounter
- Mavuso, Jabulile M-J J, Macleod, Catriona I
- Authors: Mavuso, Jabulile M-J J , Macleod, Catriona I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443749 , vital:74149 , xlink:href="https://doi.org/10.1080/13691058.2019.1674922"
- Description: Abortion providers and pregnant people who undergo abortion potentially face significant stigma. Researchers have started to explore how womxn respond to abortion stigma, usually focusing on individual strategies in managing or reducing stigma effects. Drawing on narrative data from research conducted on womxn’s and healthcare providers’ experiences of the pre-abortion healthcare encounter in the South African public health sector, we highlight how stigma may be resisted in social ways within this context. Everyday chatter and informal social support amongst womxn in the waiting room provided a counterpoint for health service providers’ ascription of shame to the womxn, and a sense of solidarity amongst the womxn. Health service providers narrated their decision to do abortion work through the socially affirming hero canonical narrative, and womxn described their counselling as helpful. These social and discursive practices resist the awfulisation of abortion and provide relief for the womxn and the healthcare providers in particular contexts.
- Full Text:
- Date Issued: 2020
- Authors: Mavuso, Jabulile M-J J , Macleod, Catriona I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443749 , vital:74149 , xlink:href="https://doi.org/10.1080/13691058.2019.1674922"
- Description: Abortion providers and pregnant people who undergo abortion potentially face significant stigma. Researchers have started to explore how womxn respond to abortion stigma, usually focusing on individual strategies in managing or reducing stigma effects. Drawing on narrative data from research conducted on womxn’s and healthcare providers’ experiences of the pre-abortion healthcare encounter in the South African public health sector, we highlight how stigma may be resisted in social ways within this context. Everyday chatter and informal social support amongst womxn in the waiting room provided a counterpoint for health service providers’ ascription of shame to the womxn, and a sense of solidarity amongst the womxn. Health service providers narrated their decision to do abortion work through the socially affirming hero canonical narrative, and womxn described their counselling as helpful. These social and discursive practices resist the awfulisation of abortion and provide relief for the womxn and the healthcare providers in particular contexts.
- Full Text:
- Date Issued: 2020
Screening for small molecule modulators of Trypanosoma brucei Hsp70 chaperone activity based upon alcyonarian coral-derived natural products
- Andreassend, Sarah K, Bentley, Stephen, Blatch, Gregory L, Boshoff, Aileen, Keyzers, Robert A
- Authors: Andreassend, Sarah K , Bentley, Stephen , Blatch, Gregory L , Boshoff, Aileen , Keyzers, Robert A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426045 , vital:72309 , xlink:href="https://doi.org/10.3390/md18020081"
- Description: The Trypanosoma brucei Hsp70/J-protein machinery plays an essential role in survival, differentiation, and pathogenesis of the protozoan parasite, and is an emerging target against African Trypanosomiasis. This study evaluated a set of small molecules, inspired by the malonganenones and nuttingins, as modulators of the chaperone activity of the cytosolic heat inducible T. brucei Hsp70 and constitutive TbHsp70.4 proteins. The compounds were assessed for cytotoxicity on both the bloodstream form of T. b. brucei parasites and a mammalian cell line. The compounds were then investigated for their modulatory effect on the aggregation suppression and ATPase activities of the TbHsp70 proteins. A structure–activity relationship for the malonganenone-class of alkaloids is proposed based upon these results.
- Full Text:
- Date Issued: 2020
- Authors: Andreassend, Sarah K , Bentley, Stephen , Blatch, Gregory L , Boshoff, Aileen , Keyzers, Robert A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426045 , vital:72309 , xlink:href="https://doi.org/10.3390/md18020081"
- Description: The Trypanosoma brucei Hsp70/J-protein machinery plays an essential role in survival, differentiation, and pathogenesis of the protozoan parasite, and is an emerging target against African Trypanosomiasis. This study evaluated a set of small molecules, inspired by the malonganenones and nuttingins, as modulators of the chaperone activity of the cytosolic heat inducible T. brucei Hsp70 and constitutive TbHsp70.4 proteins. The compounds were assessed for cytotoxicity on both the bloodstream form of T. b. brucei parasites and a mammalian cell line. The compounds were then investigated for their modulatory effect on the aggregation suppression and ATPase activities of the TbHsp70 proteins. A structure–activity relationship for the malonganenone-class of alkaloids is proposed based upon these results.
- Full Text:
- Date Issued: 2020
Screening of ectomycorrhizal and other associated fungi in South African forest nurseries
- Chartier FitzGerald, Veronique C, Dames, Joanna F, Hawley, Greer L
- Authors: Chartier FitzGerald, Veronique C , Dames, Joanna F , Hawley, Greer L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426058 , vital:72310 , xlink:href="https://hdl.handle.net/10520/ejc-soufor-v82-n4-a8"
- Description: The South African forestry industry covers approximately 1.3 million hectares and is dependent on exotic pine and eucalypt species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi. This investigation assessed levels of naturally occurring ECM colonisation of Pinus patula seedlings from 10 different South African forestry nurseries using a grid line intersect method. Fungi from colonised roots were identified using morphological characteristics and Illumina sequencing. Colonisation of seedlings in production nurseries was low (2-21%). Morphologically, the ECM fungi Thelophora terrestris, Suillus sibiricus, and the genera Russula and Pseudotomentella were identified. Molecularly, the ECM fungi T. terrestris, Inocybe jacobi and the genus Sphaerosporella, as well as several other ECM-containing families were identified, along with many saprotrophic/ endophytic fungi belonging to genera such as Penicillium, Ramasonia and Talaromyces. As can be seen, a combination of both molecular and morphological identification techniques are needed as neither is able to give a full picture of the species present in isolation. This study reveals an initial insight into the root microbiome community associated with Pinus patula seedlings, which should be taken into account when inoculation with beneficial microbes is considered. It determined that natural ECM fungal root colonisation levels are very low throughout the South African nurseries investigated, indicating the need for ECM fungal inoculation, which can increase seedling growth, viability and resistance to pathogens.
- Full Text:
- Date Issued: 2020
- Authors: Chartier FitzGerald, Veronique C , Dames, Joanna F , Hawley, Greer L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426058 , vital:72310 , xlink:href="https://hdl.handle.net/10520/ejc-soufor-v82-n4-a8"
- Description: The South African forestry industry covers approximately 1.3 million hectares and is dependent on exotic pine and eucalypt species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi. This investigation assessed levels of naturally occurring ECM colonisation of Pinus patula seedlings from 10 different South African forestry nurseries using a grid line intersect method. Fungi from colonised roots were identified using morphological characteristics and Illumina sequencing. Colonisation of seedlings in production nurseries was low (2-21%). Morphologically, the ECM fungi Thelophora terrestris, Suillus sibiricus, and the genera Russula and Pseudotomentella were identified. Molecularly, the ECM fungi T. terrestris, Inocybe jacobi and the genus Sphaerosporella, as well as several other ECM-containing families were identified, along with many saprotrophic/ endophytic fungi belonging to genera such as Penicillium, Ramasonia and Talaromyces. As can be seen, a combination of both molecular and morphological identification techniques are needed as neither is able to give a full picture of the species present in isolation. This study reveals an initial insight into the root microbiome community associated with Pinus patula seedlings, which should be taken into account when inoculation with beneficial microbes is considered. It determined that natural ECM fungal root colonisation levels are very low throughout the South African nurseries investigated, indicating the need for ECM fungal inoculation, which can increase seedling growth, viability and resistance to pathogens.
- Full Text:
- Date Issued: 2020