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Exploring targeted metagenomics and untargeted metabolomics for characterising aquaponics bacterial ecology and phytochemistry

  • Authors: Abraham, Benjamin Melakail
  • Date: 2021-10-29
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/192453 , vital:45227
  • Description: Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
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  • Date Issued: 2021-10-29

Design of Immunobiosensors for Detection of Tumor-Associated Anti-P53 Autoantibodies: Method Development

  • Authors: Adeniyi, Omotayo Kayode
  • Date: 2020
  • Subjects: Uncatalogued
  • Language: English
  • Type: thesis , text , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/162988 , vital:41002 , 10.21504/10962/162988
  • Description: Introduction -- Experimental -- Label-Free Impedimetric Sensing of Anti-P53ab... -- Fluorescent detection of Anti-P53ab -- Peroxidase-like activity of Fe3O4@SiNP-APTES-Au@Pd... -- Colorimetric detection of Anti-P53ab , Thesis (PhD)--Rhodes University, Science Faculty, Department of Chemistry, 2020. , Detection and profiling of circulating tumor-associated autoantibodies (TAAbs) are useful for screening and early-stage diagnosis of asymptomatic lung cancer. Immunobiosensor technologies aimed to accomplish the highly sensitive, rapid and low-cost detection of TAAbs can improve the early-stage detection of lung cancer. Immunobiosensors for the detection of anti-P53-tumour associated autoantibodies have been developed in this work. The design of sensing interfaces with immobilized P53 protein (P53ag) as a sensing element layer on a solid interface was investigated. Several methods of detecting anti-P53-antibodies (anti-P53ab) were investigated. These methods are label-free detection using electrochemical impedance spectroscopy (EIS) and two label techniques. The label-free electrochemical techniques utilize gold electrode pre-modified with a conducting layer of electrochemically grafted phenylethylamine for covalent immobilization of P53ag. The limit of anti-P53ab detection with the label-free EIS was 103.0 pg.ml-1. The labeled technique developed utilizes fluorescent, and peroxidase-like nanomaterial labeled antibody as a detection probe. For the fluorescence detection, fluorescent silica nanoparticles were synthesized by overloading FITC into the silica matrix and conjugated to detection antibody (anti-IgG). The detection of the anti-P53ab was based on the dissolution of the silica nanoparticles to release the loaded dye as a signal amplification strategy. The fluorescence detection was carried out on a microplate, and magnetic bead modified P53-antigen platforms and limit of detection (LoD) were 42.0 fg.ml-1 and 3.3 fg.ml-1 for anti-P53ab; respectively. Fe3O4@SiNP-APTES-Au@Pd hybrid nanoparticles were synthesized, and their peroxidase-like activity and colorimetric detection were evaluated. The Fe3O4@SiNP-APTES-Au@Pd exhibited comparable activity to HRP. The Fe3O4@SiNP-APTES-Au@Pd was conjugated to protein-G-anti-IgG for the detection of anti-P53ab on a microplate and cellulose paper platforms. The LoD was 20.0 fg.ml-1 and 63.0 fg.ml-1 for the microplate and cellulose paper platform; respectively. The potential application of the designed immunobiosensor was evaluated in simulated serum samples. The developed sensors showed higher detection sensitivity, stability and had a lower detection limit for anti-P53ab when compared with the ELISA based detection. The results have provided alternative and effective quantification approaches to ELISA and a promising future for multiplexed detection of tumor-associated autoantibodies. The developed methodologies in this thesis could be applied for the detection of other autoantibodies in other cancer types and auto-immune diseases.
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  • Date Issued: 2020

Bioprospecting for amylases, cellulases and xylanases from ericoid associated fungi, their production and characterisation for the bio-economy

  • Authors: Adeoyo, Olusegun Richard
  • Date: 2018
  • Subjects: Uncatalogued
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/64327 , vital:28533
  • Description: South Africa is one of the most productive areas for ericaceous plants with about 850 identified species in the Cape Floral Region. The Albany Centre of Endemism where all fungi used in this study were isolated from, falls within this region. Ericaceous plants interact with some fungi via an association called the ericoid mycorrhizal (ERM) association. All fungi used in this study were isolated from roots of six ericaceous plants; Erica cerinthoides, Erica demissa, Erica chamissonis, Erica glumiflora, Erica caffra and Erica nemorosa. Fungal enzymes are known to play a significant role in the food, brewing, detergent, pharmaceutical and biofuel industries. The enzyme industry is among the major sectors of the world, and additional novel sources are being explored from time to time. This study focussed on amylases (amyloglucosidase, AMG), cellulases (endoglucanase) and xylanases (endo-1,4-P-xylanase) production from ERM fungal isolates. Out of the fifty-one (51), fungal isolates screened, ChemRU330 (Leohumicola sp.), EdRU083 and EdRU002 were among the fungi that had the highest activities of all the enzymes. They were tested for the ability to produce amylases and cellulases under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28°C in a modified Melin-Norkrans (MMN) liquid medium. Cellulase specific activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and ChemRU330, respectively, was produced at an optimal pH of 5.0. For amylase, ChemRU330 had the highest specific activity of 1.11 U/mg protein while EdRU083 and EdRU02 had a specific activity of 0.80 and 0.92 U/mg protein, respectively, at the same pH with corresponding biomass yield of 113, 125 and 97 mg/50 ml, respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone, while NaFe-EDTA and cobalt inhibited enzyme activity. ChemRU330 was selected to determine the consistency and amount of amylase, cellulase and xylanase formed after several in vitro subculturing events. AMG and endo-1,4-P-xylanase were found to have the most consistent production throughout the study period. The AMG was stable at 45oC (pH 5.0), retaining approximately 65% activity over a period of 24 h. The molecular mass of AMG and endo-1,4-P-xylanase were estimated to be 101 kDa and 72 kDa, respectively. The Km and kcat were 0.38 mg/ml and 70 s-1, respectively, using soluble starch (AMG). For endo-1,4-P-xylanase, the Km and Vmax were 0.93 mg/ml and 8.54 U/ml, respectively, using beechwood xylan (endo-1,4-P-xylanase) as substrate. Additionally, crude extracts of five root endophytes with unique morphological characteristics were screened for antibacterial properties and was followed by determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). L. incrustata (ChemRU330) and Chaetomium sp. extracts exhibited varying degrees of inhibition against two Gram-positive and Gram-negative bacteria. The crude extract of L. incrustata was the most effective which was found to inhibit Staphylococcus aureus (MIC: 1 mg/ml), Bacillus subtilis (MIC: 2 mg/ml) and Proteus vulgaris (MIC: 16 mg/ml). The L. incrustata displayed potential for antibacterial production and could be considered as an additional source of new antimicrobial agents in drug and food preservation. Also, the three isolates used for enzyme production were identified to genus and species levels, i.e., Leohumicola incrustata (ChemRU330), Leohumicola sp. (EdRU083) and Oidiodendron sp. (EdRU002) using both ITS and Cox1 DNA regions. The molecular analysis results indicated that these ERM mycorrhizal fungi were similar to those successfully described by some researchers in South Africa and Australia. Therefore, this study opens new opportunities for exploring ERM fungal biomolecules for the bio-economy. The promising physicochemical properties, starch and xylan hydrolysis end- products, and being non-pathogenic make AMG and endo-1,4-P-xylanase potential candidates for future applications as additives in the food industry for the production of glucose, glucose syrups, high-fructose corn syrups, and as well as the production of bioethanol. Finally, the findings of this study revealed that it is possible to produce hydrolytic enzymes from ERM fungi in vitro using chemically defined media. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2018
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  • Date Issued: 2018

Design of immunosensor for the detection of C-reactive protein using oriented antibody immobilization

  • Authors: Adesina, Abiola Olanike
  • Date: 2020
  • Subjects: Uncatalogued
  • Language: English
  • Type: thesis , text , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/163080 , vital:41010 , https://dx.doi.org/10.21504/10962/163080
  • Description: Thesis (PhD)--Rhodes University, Science Faculty, Department of Chemistry, 2020.
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  • Date Issued: 2020

The design, synthesis and antiplasmodial activity of a series of halogenated fosmidomycin analogues and hybrid drugs

  • Authors: Afolayan, Anthonia Folake
  • Date: 2012
  • Subjects: Uncatalogued
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/64370 , vital:28538
  • Description: Malaria continues to be a devastating disease and a major cause of death in sub-Saharan Africa. With resistance against most of the available antimalarial drugs, there is a need for ongoing research and development of antimalarial agents. Fosmidomycin and its acetyl analogue FR900098 have been identified as potent inhibitors of Plasmodium falciparum, the causative agent of the most deadly form of malaria. Clinical trials of these agents have revealed poor absorption due to their high hydrophilicity. In the present studies the effect of halogenation of the acyl chain as well as the biological effect of extending the acyl sidechain was explored. This provided the basis on which fosmidomycin hybrids were designed to investigate the feasibility of hybrid extending into NADPH binding pocket. Synthesis of a series of halogenated FR900098 analogues was carried out in three stages. This included i) The introduction of the phosphonate group by reaction with 1,3dibromopropane in an Arbuzov reaction, ii) The introduction of a hydroxamate group by reaction of the propyl phosphonate by means of a nucleophilic substitution reaction with BocNHOBn and iii) The introduction of a halogenated acyl side chain on a protected fosmidomycin backbone. The synthesis of fosmidomycin-hybrids for which chloroquinefosmidomycin hybrids were used as the prototype, involved convergence of the two separately constructed moieties i.e. fosmidomycin and the quinoline moieties in a covalent linkage. The quinoline moiety was easily synthesized from the reaction of 4,7dichloroquinoline with 1,2-diamino ethane. The aminoquinoline so formed resulted in chloroquine-fosmidomycin hybrids 3.8 and 3.9 when reacted with halogenated FR900098 analogues. Antiplasmodial assays were conducted on the chloroquine-fosmidomycin hybrids and the halogenated fosmidomycin derivatives against the chloroquine resistant Gambian FCR-3 strain of P. falciparum. The most potent iodoacetyl fosmidomycin analogues 2.21 gave an IC50 value of 5.54 µM which is eight times more potent than the known antiplasmodial FR900098 which gave an IC50 value of 41.67 µM. All the halogenated FR900098 analogues showed better antiplasmodial activity than their non-halogenated derivatives. This indicated that the presence of halogens in the FR900098 analogues contributes to their biological Chapter 1 Literature review activity. The acetyl and propyl linked hybrids 3.8 and 3.9 showed potent antiplasmodial activity with IC50 values of 0.18 and 0.82 µM respectively. These were by far the most potent hybrids synthesized and provided leads for a new class of promising antimalarial agents. Preliminary E. coli DXR enzyme inhibition assays were carried out on the halogenated fosmidomycin analogues. The results showed good inhibition of the enzyme by the phosphonic acids of the chloroacetyl and chloropropyl analogues 2.1 and 2.2 respectively. Molecular modelling of the compounds on E. coli (PDB code: 2EGH) and P. falciparum (PDB code: 3AUA) DXR showed strong binding of the halogenated fosmidomycin analogues while the hybrids in the absence of docked NADPH showed minimum binding to the enzymes.
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  • Date Issued: 2012

The relative suitability of knowledge paradigms to indigenous African resource management and their implications for environmental bioethics, environmental policy and food security

  • Authors: Agbor Ambang, Oscar Mbi
  • Date: 2020-04
  • Subjects: Uncatalogued
  • Language: English
  • Type: thesis , text , Masters , M.Pharm
  • Identifier: http://hdl.handle.net/10962/163091 , vital:41011
  • Description: Thesis (M.Pharm)--Rhodes University, Faculty of Pharmacy, Pharmacy, 2020.
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  • Date Issued: 2020-04

A phenomenological investigation of the beginning therapist's experience of the first session of psychotherapy with the first patient

  • Authors: Allen, Jennifer Ann
  • Date: 1987
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/193129 , vital:45301
  • Description: The aim of this project is to come to an understanding of how the situation of the first session of psychotherapy with the first patient is lived by the beginning therapist and what meaning this situation holds for him. The writer's interest in this phenomenon grew out of her own experience of this situation as a clinical Masters coursework student, an experience which was of important to the writer and meaningful still as a therapist in training. In dialogue with experienced therapists the importance of this situation was again made apparant. It was the opinion of these therapists that although for some the details of this experience had become dulled by time, what remained meaningful to them was that this experience was seen as the beginning of a project which remains important to them - they identified this situation as an important moment in the history of their development as psychotherapists. In the hope that the literature pertaining to psychotherapy would throw some light on this situation, the writer turned to a number of sources in this area to discover that no literature available to her elucidated this situation in a holistic manner. This led the writer to go back to the beginning therapists themselves so that they may speak for themselves of their experience of this situation. A phenomenological method of enquiry is implemented in this study as it renders the subject matter accessible to investigation, and allows it to reveal itself as it essentially is. This project is then an attempt to come to a general description of the beginning therapist's experience of the first session of psychotherapy with the first patient and thus to articulate the structure of the beginning therapist's lived situation (world) in this context. , Thesis (MA) -- Faculty of Humanities, Psychology, 1987
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  • Date Issued: 1987

In silico analysis of plasmodium falciparum Hsp70-x for potential binding sites and hits

  • Authors: Amusengeri, Arnold
  • Date: 2017
  • Subjects: Uncatalogued
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/59136 , vital:27435
  • Description: Restricted access-thesis embargoed for 1 year - release date April 2019
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  • Date Issued: 2017

Self-reports on the effectiveness of psychotherapy with therapists-in-training: an 18-month follow-up study at a psychology training clinic

  • Authors: Angus, Catherine Clare
  • Date: 1993
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/193069 , vital:45295
  • Description: The purpose of this study is to ascertain whether the clients who make use of the services of the Psychology Clinic at Rhodes University perceive the masters students being trained at the Clinic as providing adequate psychotherapy. Using a sample of 18 clients, who underwent psychotherapy at the Rhodes Psychology Clinic during 1990, a follow-up study was conducted to ascertain the perceived success of that psychotherapy. Those variables most pertinent to the outcome of psychotherapy are examined. The study uses both qualitative and quantitative methodology and shows that, overall, 89% of the clients who participated in this study perceived the psychotherapy at the Rhodes Psychology Clinic to be satisfactory. The study also highlights those factors which were perceived to be negative in the psychotherapeutic equation and it is hoped that the findings can be beneficial in planning more efficient services for the Clinic in the future. , Thesis (MA) -- Faculty of Humanities, Psychology, 1993
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  • Date Issued: 1993

Composition Portfolio

  • Authors: Appollis, Sylvester
  • Date: 201u
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/193476 , vital:45335
  • Description: Composition portfolio. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 201u
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  • Date Issued: 201u

Potential of the Gravel Filter Towers, Pilot-scale Filter system and Biochar/Clay adsorbents for Bio-Physicochemical remediation and Desalination of greywater

  • Authors: Bani, Siphumze
  • Date: 2021-10-29
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/188375 , vital:44748
  • Description: Thesis embargoed until 2023 , Thesis (MSc) -- Faculty of Science, Rhodes University Biotechnology Innovation Centre, 2021
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  • Date Issued: 2021-10-29

Contributions to the study of nonholonomic Riemannian manifolds

  • Authors: Barrett, Dennis Ian
  • Date: 2017
  • Subjects: Uncatalogued
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/7554 , vital:21272 , DOI https://doi.org/10.21504/10962/7554
  • Description: In this thesis we consider nonholonomic Riemannian manifolds, and in particular, left- invariant nonholonomic Riemannian structures on Lie groups. These structures are closely related to mechanical systems with (positive definite) quadratic Lagrangians and nonholo- nomic constraints linear in velocities. In the first chapter, we review basic concepts of non- holonomic Riemannian geometry, including the left-invariant structures. We also examine the class of left-invariant structures with so-called Cartan-Schouten connections. The second chapter investigates the curvature of nonholonomic Riemannian manifolds and the Schouten and Wagner curvature tensors. The Schouten tensor is canonically associated to every non- holonomic Riemannian structure (in particular, we use it to define isometric invariants for structures on three-dimensional manifolds). By contrast, the Wagner tensor is not generally intrinsic, but can be used to characterise flat structures (i.e., those whose associated parallel transport is path-independent). The third chapter considers equivalence of nonholonomic Rie- mannian manifolds, particularly up to nonholonomic isometry. We also introduce the notion of a nonholonomic Riemannian submanifold, and investigate the conditions under which such a submanifold inherits its geometry from the enveloping space. The latter problem involves the concept of a geodesically invariant distribution, and we show it is also related to the curvature. In the last chapter we specialise to three-dimensional nonholonomic Riemannian manifolds. We consider the equivalence of such structures up to nonholonomic isometry and rescaling, and classify the left-invariant structures on the (three-dimensional) simply connected Lie groups. We also characterise the flat structures in three dimensions, and then classify the flat structures on the simply connected Lie groups. Lastly, we consider three typical examples of (left-invariant) nonholonomic Riemannian structures on three-dimensional Lie groups, two of which arise from problems in classical mechanics (viz., the Chaplygin problem and the Suslov problem). , Thesis (PhD) -- Faculty of Science, Mathematics (Pure and Applied), 2017
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  • Date Issued: 2017

"Burnout" in children's home houseparents

  • Authors: Bath, Peter John
  • Date: 1983
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/193118 , vital:45300
  • Description: Aimed at replicating the results of an American study into "Burnout" in Group Home houseparents, this research had the following aims: 1) To ascertain the validity and reliability of the instrument used in the original study and presented as a "useful measure of burnout”. 2) To establish whether this line of research, within a highly problematic research field, can at present offer any guidelines in the resolution of the current staffing crisis faced by South African children's homes. 3} To describe more closely the burnout syndrome. 4) To study possible etiological factors within a local context. Sixty three houseparents completed questionaires and three independent measures of burnout were obtained. The results were regarded as having failed to replicate those of the original study. The reason for this was found to be the low validity of the original instrument. The main conclusion drawn was that the line of research adopted in the original study can offer only very tentative guidelines towards the resolution of the staffing crisis faced until such time as valid and reliable instruments to measure burnout have been developed. Many of the suggested relationships between situational variables and ones of personal characteristics were confirmed for the local population of houseparents. , Thesis (MSocSci) -- Faculty of Humanities, Psychology, 1983
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  • Date Issued: 1983

The role of Stress Inducible Protein 1 (STI1) in the regulation of actin dynamics

  • Authors: Beckley, Samantha Joy
  • Date: 2015
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/193941 , vital:45409
  • Description: Stress-inducible protein 1 (STI1) otherwise known as Hop (Hsp70/Hsp90 organising protein) is a highly conserved abundant co-chaperone of the Hsp70 and Hsp90 chaperones. STI1 acts as an adapter protein, where it regulates the transfer of protein substrates from Hsp70 to Hsp90 during the assembly of a number of chaperone-client protein complexes. The role of STI1 associating independently with non-chaperone proteins has become increasingly prominent. Recent data from colocalisation and co-sedimentation analyses in our laboratory suggested a direct interaction between STI1 and the cytoskeletal protein, actin. However, there was a lack of information on the motifs which mediated this interaction, as well as the exact role of STI1 in the regulation of cytoskeletal dynamics. Two putative actin binding motifs, DAYKKK (within the TPR2A domain) and a polyproline region (after the DP1 domain), were identified in mammalian STI1. Our data from in vitro interaction studies including surface plasmon resonance and high speed co-sedimentation assays suggested that both TPR1 and TPR2AB were required for the STI1-actin interaction, and peptides corresponding to either the DAYKKK or the polyproline motif, alone or in combination, could not block the STI1-actin interaction. Full length mSTI1 was shown to have ATPase activity and when combined with actin an increase in ATPase activity was seen. Ex vivo studies using STI1 knockdown shRNA HEK293T cells and non-targeting control shRNA HEK293T cells showed a change of F-actin morphology as well as reduction in levels of actin-binding proteins profilin, cofilin and tubulin in the STI1 knockdown cells. These data extend our understanding of the role of STI1 in regulating actin dynamics and may have implications for cell migration. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2015
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  • Date Issued: 2015

Social upgrading or dependency?: Investigating the implications of the inclusion of commercial wine farms within South African Fairtrade certification

  • Authors: Bell, Joshua
  • Date: 2022-10-14
  • Subjects: Uncatalogued
  • Language: English
  • Type: Academic theses , Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/327155 , vital:61086 , DOI 10.21504/10962/327155
  • Description: The South African wine industry is one of the oldest sectors of the country’s economy, beginning in the early years of South African colonialism in the 17th century through the use of slave and slave-like labour. As an industry that has been defined by farm paternalism and dependency, the South African wine industry has had to demonstrate changes from its history of extreme racial and gendered exploitation to an industry that reflects the democratic values of a new South Africa. Ethical certifications are considered one way through which the post-apartheid South African wine industry can demonstrate that it has moved away from its historical practices and is now characterised by practices of decent work and social transformation. An important certificatory label that allows local wine producers entry into global wine production networks is Fairtrade International. While Fairtrade certification is often reserved for small-scale producers, this certification has been extended to large-scale, commercial producers within the South African wine industry despite its history of farm paternalism and dependency. This research asks if this inclusion promotes decent work through social upgrading or if it offers a platform for the continuation of farm dependency under the guise of ‘Fairtrade’. In this study, social upgrading has been defined through a ‘bottom-up’ approach that prioritises workers’ independence as a key means of improvement. Four key pillars are applied as embodying the concept of social upgrading: regular employment with set working hours; legally enforceable worker rights; social protection through collective and individual bargaining power; and non-discriminatory social dialogue that promotes significant socio-economic progression. A key finding of this research is that practices of dependency and paternalism continue on some large-scale commercial farms, despite their Fairtrade certification. Furthermore, the findings suggest that the benefits that farmworkers receive lock farmworkers into their position on the farm with marginally improved conditions and cease if workers depart from the Fairtrade wine farm. This suggests that, at best, this inclusion of commercial farmers within Fairtrade certification appears to create a top-down form of social upgrading that locks farmworkers into their position on the farm with marginally improved conditions and beneath a glass ceiling of development. At worst, this Fairtrade inclusion facilitates a global poverty network through paternalism and dependency under the guise of ‘Fairtrade’. As a result, where meaningful, bottom-up social upgrading may occur on South African wine farms, the study suggests that this is despite the presence of Fairtrade and not a result of it. , Thesis (PhD) -- Faculty of Humanities, Political and International Studies, 2022
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  • Date Issued: 2022-10-14

Biochemical characterisation and small molecule modulation of the interaction between two cytosolic Hsp70s from Trypanosoma brucei and potential co-chaperones

  • Authors: Bentley, Stephen John
  • Date: 2018
  • Subjects: Uncatalogued
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/63402 , vital:28407
  • Description: Expected release date-April 2019
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  • Date Issued: 2018

A study of four-dimensional oscillator groups and the associated left-invariant control affine systems

  • Authors: Biggs, Rory
  • Date: 2012
  • Subjects: Uncatalogued
  • Language: English
  • Type: thesis , text , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/164941 , vital:41186
  • Description: Thesis (MSc)--Rhodes University, Faculty of Science, Department of Mathematics, 2012
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  • Date Issued: 2012

Neutral Atomic Hydrogen in Gravitationally Lensed Systems

  • Authors: Blecher, Tariq Dylan
  • Date: 2021-10-29
  • Subjects: Uncatalogued
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/192776 , vital:45263
  • Description: Thesis (PhD) -- Faculty of Law, Law, 2021
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  • Date Issued: 2021-10-29

Diversified computational approaches for the identification of orthosteric drugs, allosteric modulators and unveiling drug resistance mechanisms: application to infectious diseases

  • Authors: Boateng, Rita Afriyie
  • Date: 2022-04-08
  • Subjects: Uncatalogued
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/234173 , vital:50169
  • Description: Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
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  • Date Issued: 2022-04-08

Synthesis and in vitro biological evaluation of 2,3-substituted quinoline derivatives

  • Authors: Bokosi, Fostino Raphael Bentry
  • Date: 2020
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/163193 , vital:41017
  • Description: The urgent need for new systemic pharmacological entities prompted us to report a library of 2,3-substituted quinoline derivatives. Considering the ubiquity of quinoline-containing compounds in pharmacologically active small molecules, synthesized 2,3-substituted quinoline derivatives were in vitro biologically evaluated for their potential antitubercular, antimalarial and antitrypanosomal activities. Quinoline scaffold was achieved by the Vilsmeier-Haack methodology, affording synthetically useful chloro and formyl substituents on C-2 and C-3 respectively. These two substituents acted as handles in expanding the chemical space around the quinoline ring. Target compounds were synthesized in six to seven steps, employing conventional synthetic organic protocols adapted from various literature. The final compounds were accessed in moderate to good yields. The structural identity of each compound was confirmed by common spectroscopic techniques. Aryl quinoline carboxamide derivatives 3.113 – 3.126 were isolated as rotamers, hence, Variable-Temperature Nuclear Magnetic Resonance (VT-NMR) was employed in resolving 1H splitting. At elevated temperature (~328 K); N-methylene carbons were not visible on 13C NMR due to signal line broadening effects. The presence of these nuclei in such cases was, however, supported by 2-dimensional NMR and high-resolution MS data. Most of the compounds achieved in this study displayed promising antimalarial activity against chloroquine-sensitive 3D7 strain of Plasmodium falciparum compared to antitrypanosomal activity against Trypanosoma brucei brucei 427 strain. In particular, compounds 3.80 and 3.108 showed superior activity against chloroquine-sensitive 3D7 P. falciparum strain with IC50 values < 1 μM. More importantly, most of the compounds were non-toxic as determined by HeLa cells, indicating their selectivity towards the parasites. Exploring the space provided on the quinoline scaffold revealed that methoxy incorporation on C-2 is very critical in enhancing antimalarial activity of this class of quinoline compounds. The preliminary SAR of compounds 3.57 – 3.72 showed that compounds containing the 3-cinnamate exhibited enhanced antimalarial activity compared to 2 and 4-cinnamates. Finally, benzamide compounds 3.113 − 3.126 showed poor activity against Mycobacterium tuberculosis H37Rv strain with only compounds 3.113, 3.117 – 3.120 and 3.126 showing appreciable MIC90 values in the range of 40 – 85 μM. , Thesis (MSc) -- Faculty of Science, Chemistry, 2020
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  • Date Issued: 2020
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