Umntu ngumntu ngabantu – Uhlalutyo nzulu lwefilosofi yobuntu kuluncwadi lukaJ.J.R. Jolobe, uJ. Solilo noW.W. Gqoba
- Authors: Benayo, Xolela
- Date: 2025-04-02
- Subjects: Ubuntu (Philosophy) , Afrocentrism , Ethnoscience , Oral tradition , Pan-Africanism , Education, Higher South Africa , Jolobe, James J R Criticism and interpretation , Solilo, John Criticism and interpretation , Gqoba, William Wellington Criticism and interpretation
- Language: Xhosa
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/478489 , vital:78191 , DOI 10.21504/10962/478489
- Description: Ubuntu njengefilosofi yamaAfrika egxile kwindlela yokuziphatha nokuphilisana kumzi oNtsundu kudala yaba yingxoxo kwiinkalo ezahlukileyo ezifana nezopolitiko, ezemfundo, ezolawulo ukubala nje ezimbalwa. Njengoko Ubuntu buyingxoxo ekhula mihla le, kubabhali abafana noW.W. Gqoba, uJ. Solilo kunye noJ.J.R. Jolobe lushokoxekile uncwadi oluphanda ngendlela aba babhali abathe babonakalisa ngayo Ubuntu bekwahlaba ikhwelo ngeendlela zokulondoloza Ubuntu kwiimbalo zabo. Le thisisi iza kushukuxa indlela abathe aba babhali bahlaba ngayo ikhwelo ekubonakaliseni Ubuntu nendlela obunokuthi Ubuntu busetyenziswe ngayo ukuqinisekisa ukuba umzi oNtsundu awubonwa njengalowo ungaphucukanga, ungenakho ukusebenzisa iingcamango zobuntu ukuwuphuhlisa. Uphando luza kugocagoca ezi ncwadi zilandelayo: Umyezo ngokubhalwe nguJ.J.R. Jolobe ; Ilitha (isihobe) ngokubhalwe nguJ.J.R. Jolobe ; Elundini loThukela (iprozi) ngokubhalwe nguJ.J.R. Jolobe ; Isizwe esinembali: Xhosa histories and poetry (1837-1888) ngokubhalwe nguW.W. Gqoba ; Umoya wembongi: Collected Poems (1922-1935) ngokubhalwe nguJ. Solilo Uphando lukhethe ezi ncwadi zikhankanywe apha ngentla kuba zona ziyibalisa ngokucacileyo imbali yamaAfrika. Ezi ncwadi zinembali etyebileyo nezithi zisebenze njengokubhebhetha indlela amakoloniyali athi ayibhala ngayo imbali yamaAfrika eyayijolise ukuwajongela phantsi. Kwakhona olu ncwadi lwabhalwa ngexesha apho kwakukho imingeni ekunikeni inkcazo evakalayo ngokuba kuthetha ukuthini ukuphucuka, nokuba amaAfrika ayezibandakanya njani ukulwa nokuphikisa ingcaciso yendlela yokuphila kwamaAfrika yempi yaseNtshona. Ezi mbalo kungaxoxwa ngelithi, zithi zibe zezo zinike ngcaciso yimbi ngomba wempucuko leyo ingenokoyanyaniswa neengcamangco zaseNtshona. Apha kwezi ncwadi kuza kuhlutywa indlela Ubuntu obuthe baphuhla baze baphinda badodobala ngayo phantsi kolawulo lwempi yaseNtshona. Ekwenzeni oko, umphandi akayibethisanga ngoyaba imbali yoMzantsi Afrika neAfrika nje ngokubanzi, imbali yobukoloniyali. Yile mbali yobukoloniyali ethe yabangela ukuba aba babhali bezi ncwadi eziza kuphicothwa luphando bayithathele kubo ezandleni indima yokuqinisekisa ukuba iingcamango nemimiselo yobuntu yileyo bathi babhale ngayo ngeenjongo zokwenza uluntu lungaphulukani nokuxabisa Ubuntu njengefilosofi. Uphando lubone kubalulekile ukuba lulandele iingcamango zeAfrocentricity nezo zomanyan lwamaAfrika (Pan Africanism) ekubhentsiseni obu buntu bubonakaliswa ngaba babhali. Uphando luchonge ezi thiyori zimbini, eyeAfrocentricity kwakunye neyomanyano lwamaAfrika (Pan Africanism) kuba zombini ezi thiyori zikhokelisa phambili ukuxatyiswa kwamaAfrika njengabantu ekukudala benazo iifilosofi ezijolise ekuphuhliseni umzi oNtsundu. Kubonakele kufanelekile ukuba iphulo lokuphanda ngendlela Ubuntu obubonakaliswe ngayo ngaba babhali lenziwe ukukhumbula imisebenzi emikhulu eyenziwe ngamaqhawe abantu abaNtsundu nabathe banegalelo elikhulu ekuphakanyisweni koncwadi lwemveli kwakunye nenkqubela phambili kwimfundo yabantu abangamaAfrika. Ngokuphandle uncwadi lwaba babhali lubonakele luyinxalenye yobomi babo. Kukwakufumaniseka ukuba babhale bandululwe zizinto ezithe azabaphatha kakuhle ebomini babo zaze ezo zinto zawuphazamisa umoya wabo nentlalo yabo bada baqonda ukuba mababhale, baphokoze oku kuphuphuma kweengcinga zabo ukuthuthuzela kwanokuphilisa abanye abantu abathe badibana neenzima ezinjalo zobomi. Phakathi kwezo meko singabala iimeko zopolitiko zeli lizwe ezithe zabuchaphazela ubomi babo, imeko yezemfundo ethe yabonakala inomkhethe, iinqobo zenkcubeko ekuthe kwaphawuleka ukuba zibethiswe ngoyaba ngabo basemagunyeni de zenza noluntu lungazithatheli ngqalelo. Ezi meko zazibonwa njengezo zingelolutho ekuphuhliseni ubomi boluntu nje ngokubanzi. Oku kunyhashwa kwamalungelo abantu kwakunye neemeko ezimbi abathubeleze kuzo zibe sisizekabani sokwenziwa kolu phando ngobuntu nokuvuselela izazela zoluntu. Ezi mbalo zihlalutyiweyo ziquka nogxekoncomo lwazo zenza kanye le nto ichazwe kuphando, ukudakanca indlela Ubuntu obungasetyenziswa ngayo ukuphuhlisa isizwe esiNtsundu. Ziimbalo ezi ezigqithisa umyalezo neembono zaba bahlali ngokulondolozwa kwenkcubeko igcinwe encwadini njengamabali anika umdla erhwebesha uthando loncwadi kwanobuzwe babafundi abaNtsundu ngokubanzi, ingakumbi abafundi abangamaXhosa kuba babhalele bona ikakhulu. Ngababhali aba ababhale ngesiXhosa esiphakamisa inkcubeko yabo. Okuphawulekayo ngokukodwa kuJolobe yinto yokuba kwinoveli yakhe ethi, Elundini loThukela (1959) ude wasebenzisa iilwimi ezimbini isiHlubi kunye nesiXhosa eziqulethe iinkcubeko zazo. Ukongeza, ekubhaleni ngolwimi lwabo lwenkobe, aba babhali balandela ikhondo nesikhokelo sabantu abafana noMqhayi, noWa Thiong’o abazimvo ngokulondolozwa kolwimi noncwadi zikwasetyenzisiwe ukubonakalisa ukubaluleka kweelwimi zamaAfrika kuncwadi. Ekuhlalutyeni ezi mbalo zikhethiweyo, umphandi ukhethe ukulandela indlela yophando eyikwalitheyithuvu ngokugxininisa kuhlalutyo lomxholo. Isizathu sokuba indlela enjalo ibe iyasetyenziswa kukuba idatha ehlalutyiweyo ivela kwidatha esele yapapashwa, iincwadi ukutsho. Le ndlela yindlela eya kuba sisikhokelo esiphambili somphandi ukuqinisekisa ukuba iinjongo zophando ziyafezekiswa. Uphando lufumanise ukuba aba babhali bakhethiweyo bathe ngokwenene banendima abayenzayo ukuqinisekisa ukuba iziseko zobuntu ziyalondolozwa. Oku kuqala kwimiba engenkcubeko apho kuxoxwe ngelithi, umntu oNtsundu kuyafuneka ukuba angayibethisi ngoyaba into yokuzingca ngobuni bakhe. Kananjalo njengababhali ababe bhala beqwalasela yonke imiba yentlalo, into engokuzilanda ngokobuzwe yinto ebonakala isembindini kwiimbalo zabo njengoko besenza ikhwelo ebantwini abaNtsundu ukuba baze bangayilibali imvelaphi yabo. Kumba wezemfundo ingakumbi uGqoba ubalula ukubaluleka kwemfundo yemveli. Kolu phando kufumaniseke ukuba kwiimbalo zabo ababhali bayilwela ngamandla into yokumanyaniswa kwemfundo yaseNtshona naleyo yemveli yamaAfrika. Oku ingasisakhelo sokuqinisekisa ukuba umntwana womgquba uyafikelela kwimfundo ekwaziyo ukuthetha ngeengxaki ezihlangabezana nabantu abaNtsundu gabalala. , Ubuntu as an African philosophy with its focus on issues of good behavior and welfare of black Africans has forever been an unending debate on various spheres of life: those of politics, education, and governance, to name a few. Even though it is a debate with new avenues daily, there is limited research on the works of W.W. Gqoba, J. Solilo, and J.J.R. Jolobe on how they have argued on ways in which the values of Ubuntu may be preserved. This study is therefore undertaken to investigate exactly how these writers maintained in their writings ways in which Ubuntu can be used to ensure black Africans are not seen as a society that is ‘backward’, a society that cannot use Ubuntu principles for development. The research will examine the following books: Umyezo (poems) by J.J.R. Jolobe ; Ilitha (poems) by J.J.R. Jolobe ; Elundini loThukela (prose) by J.J.R. Jolobe ; Isizwe esinembali: Xhosa histories and poetry (1837-1888) by W.W. Gqoba ; Umoya wembongi: Collected Poems (1922-1935) by J. Solilo. In short, it is argued in the study that the selected texts are fine literary products and that their narratives were created following African history. They form part of negating the negative element that has been created by the accounts of colonial masters, as such an account of history was meant to undermine Africans: rich literature and history. Moreover, they were written at a time when there were challenges associated with civilization: what was meant by it and how Africans related to the idea as per Western standards. These texts, it could be argued, present an alternative on this matter by removing Western thoughts on what really are the elements of cultural civilization. In an in-depth analysis of selected writers’ texts, it was important to examine the ways in which Ubuntu has developed and evolved over the years under the administration of Western powers. In the analysis, the researcher did not turn a blind eye to the colonial history of South Africa and that of Africa in general. In that history, an argument is as follows: the thoughts and values of Ubuntu as captured by these writers are to remind people to appreciate Ubuntu as a philisophy. In my analysis, it was important to use theories such as Afrocentricity and Pan-Africanism in understanding and decoding Ubuntu as depicted in the writings of the selected writers. In choosing these theories, it is due to their main argument emphasizing the value of being African and the fact that Africans have long had their philosophies meant for the betterment of the society. It seemed appropriate to investigate how Ubuntu, as shown by these writers, is recorded to act as a reminder of the great works done by Africans who contributed greatly to the promotion of African literature as well as progress in the education of African people. The literature of these writers should be seen as an integral part of their lives. It is also found that they wrote because of the ills that affected their lives and disturbed their spirit and well-being until they realized that they should write and express their thoughts to comfort and heal other people who have encountered such hardships in life. Among those are the political conditions of this country that have affected their lives, the educational situation that has been shown to be biased, and cultural things that have been noticed to be ignored by those in power as they made the public not pay attention to them. This is because they were seen as having little value in the development of human life in general. That is why this research on Ubuntu could be seen as an initiative aimed precisely at those ideas that can be 'revitalized’ by conscientious people. The analysis of literary texts includes criticism to address the main question in this research: how Ubuntu can be used to develop the Africans. This is the kind of literature that conveys the message and ideas on the preservation of culture as preserved in the books with interesting stories that appeal to the love of literature and the nationalism of Africans in general, especially Xhosa people because they wrote mainly for them. It is these writers who wrote in Xhosa that promote their culture. What is particularly remarkable about Jolobe is the fact that in his novel, Elundini loThukela (1959), he used two languages, isiHlubi and isiXhosa, which contain their own cultures. In addition, in writing in their mother tongue, these writers follow the path and guidance of people like Mqhayi and Wa Thiong'o, whose views on the preservation of language and literature have also been used to show the importance of African languages in literary analysis. In the analysis of these selected texts, I have opted to follow a qualitative research approach with a focus on content analysis. The reason behing such an approach is the fact that the data so analysed is from existing data, books. This approach is one that will be a key guide for the researcher to ensure that the aims of the study are achieved. In this research, it was found that these selected writers really have played to ensure that the fundamental values of Ubuntu are preserved. This starts with non-cultural issues: it has been argued that the Africans should not ignore the pride of their identity. Also, as writers who wrote considering all social issues, the issue of national identity is something that appears at the centre of their writings as they call upon Africans not to forget their origins. In terms of education, Gqoba especially mentions the importance of African traditional education. In this research, it has been found that in their writings, the writers are strongly advocating for the integration of Western education with that of African traditional education. This could be taken as framework to make sure that the African child has access to an education that addresses the problems faced by Africans at large. , Thesis (PhD) -- Faculty of Humanities, Languages and Literatures, 2025
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Prediction of mass spectra using an ab initio approach
- Authors: Novokoza, Yolanda
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/${Handle} , vital:72818
- Description: Access restricted. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
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Screening isolation and biological characterization of antibacterial secondary metabolites from macrofauna endemic to the southern African coast
- Authors: Njanje, Idris
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431944 , vital:72817
- Description: Access restricted. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
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The effects of inclusive education policies and administrative circulars on small schools in Namibia
- Authors: Hamutumua, Teopolina Ndilina-Laudika
- Date: 2023-10-13
- Subjects: Inclusive education Namibia Kavango West , Education and state Namibia , Small schools Namibia Kavango West , Right to education Namibia Kavango West , Education Social aspects Namibia Kavango West , Business communication
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/419737 , vital:71671
- Description: The achievement of the right to education for all children in Namibia is fundamentally dependent upon the quality of education provided to these learners irrespective of their social circumstances. Being a sparsely populated region, nearly half of the primary schools in the Kavango West region have fewer than 100 learners; thus, these small schools are regarded as not economically viable. The educational development in rural regions is shaped by limited access to quality, inclusive education and the persistence of low-quality primary education which has resulted in high repetition rates and dropouts. This research is a Critical Discourse Analysis of the education policies and regulations. As a case study, it unpacks Formal Education Circulars on staffing norms and on the closure of small schools, looking at their affordances/constraints on the provision of inclusive quality education for children schooling at small schools in Namibia. Interviews and document analysis were used to gather data. Critical Theory frames the process of ideological critique which, among other things, identifies inequalities and factors that limit human freedom and how such factors can be alleviated. The research asks the question: what are the explicit and implicit underlying realities experienced at one-man schools, which depict the varied situations in which these schools survive? Factors emerging from the study showed that small schools in Namibia are symbols of inequity and the exclusion of educationally marginalised children and their poor communities. Small schools are hardly able to sustain and draw in the resources required to meet the education needs of marginalised communities which fall under the multidimensional poverty index in Namibia. The study found that at the moment there are no deliberate efforts from the Ministry of Education to bring about the necessary changes to small schools, and therefore one-man schools have continued to operate as isolated sections of an inflexible system. It is my contention that deliberate efforts are still needed to improve small schools. Policy decisions that respond to the current challenges faced by one-man schools may be sufficient to bring about noteworthy changes in the operations of one-man schools and these changes could effectively impact the learners learning. The decision to drive change requires a multilayered approach that articulates a clear vision, which is systematically implemented to improve one-man schools in Namibia. , Thesis (MEd) -- Faculty of Education, Primary and Early Chilhood Education, 2023
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The photodynamic therapeutic activities and optical limiting properties of metalated asymmetric porphyrins and corroles
- Authors: Burgess, Kristen Paige
- Date: 2023-10-13
- Subjects: Porphyrins , Corrole , Photochemotherapy , Anti-infective agents , Nonlinear optics , Z-scan technique , Active oxygen , Time-dependent density functional theory , Chemical synthesis
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424490 , vital:72158
- Description: Cancer is a devastating disease that is a leading cause of death worldwide. Despite the available cancer treatments, there is a significant need to improve the therapeutic approach towards this disease. Photodynamic therapy (PDT) is an alternative approach for treating cancer, which requires a photosensitiser, molecular oxygen and light. Although some porphyrin-based derivatives have been approved by the United States Food and Drug Administration (FDA) and other similar agencies elsewhere for photodynamic therapy, their relatively poor photophysicochemical properties mean that there is an ongoing need for new photosensitiser dyes. Singlet oxygen photosensitiser dyes can also be used to treat bacteria that develop antimicrobial resistance in the context of photodynamic antimicrobial chemotherapy (PACT). The main aim of this study was to synthesise and characterise a series of porphyrin dyes with 4-quinolinyl, thien-2-yl and 4-bromo-thien-2-yl meso-aryl groups and their Sn(IV) and In(III) complexes, as well as their corrole analogues. Corroles are contracted macrocycles that have interesting optical properties. The corroles selected for study were found to be difficult to synthesise and purify and had unfavourable photophysicochemical properties and were thus omitted from the PDT and PACT biological applications within this thesis. High- and low-symmetry A4 and ABAB type meso-tetraarylporphyrins porphyrins were synthesised to improve the photophysicochemical properties of the photosensitisers; the utility of these dyes as photosensitisers was studied against the MCF-7 breast cancer cell line for PDT and against Staphylococcus aureus and Escherichia coli for PACT. The thienyl-2-yl rings were introduced to red shift the lowest energy Q band towards the phototherapeutic window, while quaternisation of the nitrogen and sulfur atoms of the 4-quinolinyl and thien-2-yl rings to introduce a cationic nature was explored to improve the bioavailability of the drugs and uptake into the target cell walls for improved efficacy. Heavy Sn(IV) and In(III) central metal ions were introduced to enhance the singlet oxygen quantum yields and limit aggregation through axial ligation. The bromine atoms of the 4-bromo-thien-2-yl meso-aryl rings were also introduced to enhance the singlet oxygen quantum yields of the dyes. Furthermore, the utility of the porphyrin and corrole molecules for optical limiting properties to limit laser radiation to protect optical devices, including eyes, was explored by the z-scan technique. One of the dyes studied, Sn(IV) tetrathien-2-ylporphyrin, that exhibited the most favourable reverse saturable absorbance (RSA) response was embedded into a poly(bisphenol carbonate A) polymer thin film to further explore its suitability for practical applications. , Thesis (MSc) -- Faculty of Science, Chemistry, 2023
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Visualisation processes in teaching patterns and their generalisation: perceptions and experiences from senior phase mathematics teachers
- Authors: Chatima, Simon
- Date: 2022-04-08
- Subjects: Visual learning South Africa Eastern Cape , Mathematics Study and teaching (Secondary) South Africa Eastern Cape , Mathematics teachers South Africa Eastern Cape Attitudes , Sequences (Mathematics) Study and teaching (Secondary) South Africa Eastern Cape , Constructivism (Education) South Africa Eastern Cape , Mathematics teachers In-service training South Africa Eastern Cape , VIPRO MATHS Project
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232936 , vital:50039
- Description: This study investigated how senior phase mathematics teachers used visualisation approaches to teach patterns and their generalisation as a result of an intervention programme. This project is an integral component of the VIPRO MATHS Project and one of a number of post-graduate research projects which has a particular focus on visualisation processes in mathematics education in the Southern African region. This case study of Senior Phase mathematics teachers in the Chris Hani West District (CHW) in the Eastern Cape Province of South Africa used a social constructivist theory. The study is grounded within an interpretive paradigm explanatory qualitative method design. It surveyed thirty-seven Senior Phase mathematics teachers from schools in the CHW district to get an idea of how teachers teach patterns and their generalisation, prior to an intervention process. After the survey, nine teachers were purposively selected to take part in an intervention programme. They were then observed (teaching) and interviewed to get their perceptions about what factors enable and/or constrain the teaching of patterns and their generalisation when visualisation approaches were used. The data from the survey questionnaire responses, the lesson observations and the interviews were analysed qualitatively. The findings from the survey questionnaire responses revealed that teachers in CHW district value the use of visualisation approaches, although they used visuals to teach patterns in a way that lacked depth, skill and rigor prior to the intervention. Challenges such as difficulty in keeping abreast with the prescribed syllabus, the lack of resources, time constraints, and the limited knowledge of algebra learners have for successfully transferring pictorial representations to symbolic presentations, emerged from the survey data. This necessitated the need for an intervention which focused on the use of a variety of visual strategies and tools to teach patterns and their generalisation effectively. Data from lesson observations showed that all observed participant teachers used visuals to generate image- related questions and created platforms for lively classroom discussions. The teachers used the generated questions to build on learners’ prior knowledge and to promote learner understanding of pattern dynamics that stem from pictorial representations. The data from the interviews revealed that teachers’ perceptions had drastically changed after the intervention. This was because they were now equipped and empowered to effectively make use of visual strategies that enabled them to: build on learners’ prior knowledge, to manipulate visuals for the purpose of prompting learning, develop cognitive perception in learners, cultivate learner innovation and originality and enhance problem solving techniques. This study concludes that the use of visuals enhanced conceptual teaching of patterns and their generalisation in the observed participants. This has the potential to provide mathematics education researchers and curriculum developers with a strong basis to include visualisation processes and strategies into the design of policy documents and to initiate further research efforts. The implications for the teachers are that learners need to be taught ways to create and interpret visual representations in order to understand the dynamics of transferring a pictorial pattern to its resultant symbolic representation expressing pattern regularity. It is also hoped that the results of this study will be utilised by mathematics subject advisers and teacher training institutions to improve the teaching of patterns and their generalisation. , Thesis (MEd) -- Faculty of Education, Education, 2022
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Interaction of catechol O-methyltransferase with gold and silver nanoparticles
- Authors: Usman, Aminu
- Date: 2018
- Subjects: Parkinson's disease , Methyltransferases , Catechol , Nanoparticles
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/61818 , vital:28063 , DOI https://doi.org/10.21504/10962/61818
- Description: Catechol O-methyltransferase (S-adenosyl-Z-methionine: catechol O-methyltransferase; COMT; EC 2.1.1.6) is a ubiquitous enzyme that catalyses the transfer of a methyl group from the cofactor, S-adenosyl-Z-methionine (SAM) to a hydroxyl group of endogenous and exogenous catechol-containing moieties. The physiological role of this enzyme is the methylation and thereby inactivation of the catechol-containing bio-active and bio-toxic compounds, including catechol-neurotransmitters, catechol-estrogens and catechol-containing drugs. Activity of this enzyme is implicated in the treatment of Parkinson’s disease and is associated with other diseases including breast cancer and an array neuropsychological disorders, such as schizophrenia. This thesis explores the use of gold and silver nanoparticles (NPs) (AuNPs and AgNPs) to inhibit the catalytic activity of mammalian COMT. Because of its accessibility and availability, we initially investigated bovine soluble COMT (BSCOMT) from liver tissue. Bioinformatic analyses and structural modeling revealed high (>90%) sequence similarity between BSCOMT and human soluble COMT (HSCOMT). BSCOMT was partially purified to 7.78 fold, 1.65% yield and had a specific activity of 0.052 U/mg. It had pH and temperature optima of 8.5 and 40oC, respectively. The Km, Vmax, Kcat and Kcat/Km towards esculetin methylation were respectively 1.475±0.130 pM, 0.0353±0.001 pmol/ml/min, 1.748 x 10-2±5.0x10-4 min-1 and 1.18x10-2 M-1. min-1. HSCOMT was expressed in Escherichia coli BL21(DE3) which showed optimal activity for esculetin methylation at pH and temperature of 7.0 and 30°C, respectively. It was purified to 5.62 fold, 22.6% yield with a specific activity of 3.85 U/mg. HSCOMT kinetic plots, upon incubation of the reaction mixture at 30°C for 5 min before addition of SAM was hyperbolic with Km, Vmax, Kcat and Kcat/Km values of 1.79 pM, 0.412 pmol/ml/min, 2.08 min-1 and 1.165 M-1. min-1, respectively. AuNPs and AgNPs showed a concentration dependent inhibition of HSCOMT activity upon increasing the 5 min incubation time to 1 h. Interestingly, HSCOMT kinetics, with 1 h incubation at 30°C, showed a sigmoidal curve, as well as increased activity. Incubation of the reaction mixture in the presence of 60 pM AuNPs and/or AgNPs for 1 hreversed the observed sigmoidal to a hyperbolic curve, with kinetic parameters comparable to those of 5 min incubation. SDS-PAGE analyses of HSCOMT after the kinetic experiments showed the enzyme incubated for 5 min as a monomer, while that which was incubated for 1 h migrated substantially as dimer. However, the HSCOMT incubated for 1 h in the presence of 60 pM AuNPs and/or AgNPs migrated as a monomer. This indicated that the extension of the incubation period allowed the dimerization of HSCOMT, which exhibited sigmoidal kinetics and higher activity. The presence of NPs impeded the HSCOMT dimerization which decreased the activity. Varying the concentration of SAM suggested that SAM had an allosteric modulatory effect on HSCOMT. Absorption spectroscopy indicated adsorption of HSCOMT on the gold and silver NP surfaces and the formation of NPs-HSCOMT corona. Fluorescence spectroscopy showed that the interaction of HSCOMT with both gold and silver NPs was governed by a static quenching mechanism, implying the formation of a non-fluorescent fluorophore-NP complex at the ground state. Further fluorometric analyses indicated that both gold and silver NPs had contact with Trp143; that the interactions were spontaneous and were driven by electrostatic interactions. Fourier transform infrared spectroscopic studies showed the adsorption of HSCOMT of the NPs surfaces to cause relaxation of the enzyme’s B-sheet structures. Molecular docking studies indicated involvement of largely hydrophilic amino acids, with the interacting distances of less than 3.5A. These findings signify the potential of nanotechnology in the control of COMT catalytic activity for the management of the COMT-related disorders. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2018
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Composition and fate of triclosan in the sludge from wastewater treatment in Grahamstown, South Africa and Tiaret, Algeria
- Authors: Ncube, Mbonisi
- Date: 2017
- Subjects: Sewage sludge , Sewage Purification South Africa Grahamstown , Sewage Purification Algeria Tiaret , Sewage sludge as fertilizer , Anti-infective agents
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65156 , vital:28697
- Description: Physicochemical properties such as pH, specific surface area (SSA), cationic exchange capacity (CEC), loss on ignition (LOI), pathogens, plant nutrients (nitrates, ammonium and phosphates), and heavy metals (manganese, copper, lead and cadmium) were determined for sewage sludge from Grahamstown and Tiaret. The values obtained were log transformed thereafter a t-test at 5 % level of significance was used to test for the difference in each parameter for both sludges. The pH of sludge was determined in 1:3 water, 16 water, 1:3 0.01 M calcium chloride and 1:3 1 M potassium chloride. The pH for Grahamstown and Tiaret sludge were in the ranges of 6.66-7.11 and 7.88-8.18 respectively. The SSA values for Grahamstown and Tiaret were 218 ± 108 and 261 ± 99.9 m2/g, and the CEC values were 119 ± 2.09 and 136 ± 6.03 mEq/100, respectively. The LOI values obtained were 1.33 ± 0.03 and 1.48 ± 0.11 % for Grahamstown and Tiaret, respectively. E. coll and heterotrophic bacteria were the pathogens determined, and were extracted from sludge using sterile saline and nutrient broth. The concentration of E. coll in Grahamstown and Tiaret sludge were 468 ± 7.63 and 7769 ± 1268 CFU/g d.w and for heterotrophic bacteria were 1.17x109 ± 7.42x108 and 1.43x109 ± 9.11 x108 CFU/g d.w. For Grahamstown sludge, the concentration of nitrates, ammonium and phosphates were 55.61 ± 55.20 mg/g d.w, 6.60 ± 2.36 mg/g d.w and 1.40 ± 0.30 mg/g d.w, respectively. For Tiaret sludge, the concentration of nitrates, ammonium and phosphates were 2.56 ± 2.90 mg/g d.w, 0.64 ± 0.45 mg/g d.w and 0.24 ± 0.19 mg/g d.w, respectively. The concentration of Mn, Cu, Pb and Cd in Grahamstown sludge were 423 ± 101, 353 ± 92, 40.2 ± 20 and 0.0 mg/kg d.w respectively, and for Tiaret sludge, the corresponding concentrations were 358± 295, 549±50, 1427± 1352 and 1.54 ± 0.61 mg/kg d.w. Sewage sludge was found to contain Triclosan, and solubility studies of the compound were conducted using sodium deoxycholate and sodium lithocholate. The apparent solubilities and rate constants indicated in brackets of TCS at 37 °C were 35.4 ± 1.21 mg/L (1.28 ± 0.36 Hr-) and 14.4 ± 0.34 mg/L (0.99 ± 0.17 Hr-) in sodium lithocholate and sodium deoxycholate, respectively. The apparent solubilities and rate constants indicated in brackets of TCS at 15 °C were 32.3 ± 0.88 mg/L (2.16 ± 0.80 Hr-) and 14.2 ± 0.39 mg/L (1.02 ± 0.17 Hr-) in sodium lithocholate and sodium deoxycholate, respectively. Triclosan was extracted from sludge using 1 g/L sodium deoxycholate and the determined concentration were 142 ± 33.5 gg/g d.w for Grahamstown sludge and 0-12 gg/g d.w for Tiaret sludge. Finally plant growth studies were conducted on radish and garden cress plants using Grahamstown sludge at 0, 20, 40, 80 and 100 % treatments. Statistical analysis (t-test and Kruskal-Wallis) at 5 % level of significance was done to compare growth parameters between control and different sludge treatments. For radish plants, the values for plant height, root length, number of leaves, leaf length and dry mass were 28.4-80-7 mm, 4.3-44.7 mm, 3.3-17.0 mm, 2.3-4.0 leaves and 6.3-15.3 %, respectively. For garden cress, the values for plant height, root length, number of leaves, leaf length and dry mass were 13.7-25.0 mm, 7.7-20.3 mm, 5.7-8.3 leaves, 3.0-8.3 mm and 8.8-15.0 %, respectively. Twenty percent (20 %) sludge treatment gave the best results in radish and garden cress plants with respect to plant height, root length, number of leaves and dry mass. Triclosan concentration in radish and garden cress plants was below the detection limit of 32.4 gg/g d.w. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
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