The amidohydrolase superfamily is a functionally diverse group of evolutionarily related proteins which utilize metal cofactors in the activation of a hydrolytic water molecule and in the stabilization of the resulting tetrahedral intermediate. Members of this superfamily have been described which use one or two divalent transition metals. These metal cofactors are located in either or both of two active-site metal binding centers which are labeled as the Ma and MB sites. The goal of this research was to elucidate the nature of the reactions catalyzed by Ma and MB mononuclear members of the amidohydrolase superfamily. This was approached through comprehensive mechanistic evaluations of two enzymes which utilized the different metal sites. Nacetyl- D-glucosamine-6-phosphate deacetylase from E. coli (NagA) and cytosine deaminase from E. coli (CDA) served as models for mononuclear amidohydrolase superfamily enzymes which have evolved to utilize a single B-metal and a single a-metal for hydrolysis, respectively. This research elucidated the different properties imparted by the distinct a and B active sites and the specific interactions utilized by the enzymes for substrate binding and catalysis. These studies led to the eventual proposal of detailed chemical mechanisms and the identification of rate determining steps. Knowledge of sequence-function relationships was applied toward the discovery of function for enzymes related to cytosine deaminase and guanine deaminase. The first group of enzymes investigated was proposed to catalyze the fourth step in riboflavin and coenzyme F420 biosynthesis in Achaea. Three putative deaminases; Mm0823 from Methanosarcina mazei, MmarC7_0625 from Methanococcus maripaludis C7 and Sso0398 from Sulfolobus solfataricus were cloned and expressed. These proteins proved to be intractably insoluble. A second set of enzymes, Pa0142 from Pseudomonas aeruginosa PA01 and SGX-9236e (with crystal structure PDB: 3HPA) were found to catalyze the novel deamination of 8-oxoguanine, a mutagenic product of DNA oxidation. 9236e was cloned from an unidentified environmental sample of the Sargasso Sea. The closest homolog (98% identical) is Bcep18194_A5267 from Burkholderia sp. 383. Additionally, it was discovered that the proteins SGX-9339a (with crystal structure PDB: 2PAJ) and SGX-9236b catalyzed the deamination of isoxanthopterin and pterin-6- carboxylate in a poorly characterized folate degradation pathway. These enzymes were also from unknown environmental samples of the Sargasso Sea. The closest homolog of 9339a (88% identical) is Bxe_A2016 from Burkholderia xenovorans LB400. The closest homolog of 9236b (95% identical) is Bphyt_7136 from Burkholderia phytofirmans PsJN.

This research focused on the study of the amino sugar recycling and sialic acid degradation pathway as a possible entry point for N-acyl glucosamines for the production of sialic acid analogs. Meeting this objective would allow the development of a bacterial strain capable of producing non-natural nonulosonic acids that could be used in the development of medicines, vaccines or useful compounds for the study of interactions between pathogenic organisms and their host. The first step was to understand how N-acetyl-D-glucosamine-6-phosphate deacetylase reacts to different types of substrates in order to determine its tolerance to the size of acyl groups in acyl amino sugars. This was achieved by studying the enzymatic activity in an in vitro system. We determine that the enzyme has a preference for small and slightly bulky acyl groups. Then, an in silico docking modeling and an in vivo system experiment were carried out. These experiments allowed to confirm the previous results. The second project was carried out due to the uncertainty of whether the kinase involved in the catabolic pathway would be able to phosphorylate the substrates. By quantifying residual ATP, the high specificity of N-acetyl-D-glucosamine kinase could be verified. This result led us to think about the design of an organic synthesis strategy that would allow the phosphorylation of glucosamine in carbon 6. A simple synthetic route was designed based on the protection of the two most reactive moieties of the amino sugars and the reactivity of the hydroxy group on carbon 6. However, we had problems with the purification step of the final product due to its high polarity. The next stage of this investigation was to confirm the transformation of GlcNAc into ManNAc. For this, an NMR analysis was designed that would detect the presence of both sugars in the reaction system. The epimerization of ManNAc to GlcNAc was detected successfully. Notwithstanding, the reverse reaction could not be detected. Based on the results obtained in the previous stage, we realized that an error was made in the epimerization reaction since we placed the wrong kinase because we did not take into account its substrate specificity. Finally, we tried to produce sialic acid analogs in a fermentative system using different genetic variants of Escherichia coli. Two of the expected analogs, Neu5Pr and Neu5nBu, were obtained. In addition, NagA activity towards substrates with small acyl groups was confirmed.

This doctoral thesis explores the entanglement of religion and identity politics in the Indo-Burma borderlands and the indigenisation of Christianity there through grassroots processes of cultural revivalism. The ethnographic focus is on the Sumi Naga from the state of Nagaland in Northeast India. While the Sumi started converting to Baptist Christianity at the beginning of the twentieth century, conversion rates accelerated especially in the 1950s and again in the 1970s when two evangelical revivals swept across the lands of the Sumi and resulted in their conversion en masse. Significantly, these Great Revivals coincided in time with the most turbulent political history of this borderland region, as the Sumi, alongside all other Naga, were waging an armed struggle against the Indian nation-state for their right to self-determination and independence. While this struggle is now largely being fought with political rather than military means, it remains ideologically motivated by Naga perceptions of their distinct ethnic identity, history and culture compared to the rest of India. Baptist Christianity has played a central role in shaping and sustaining these perceptions. Over the past several decades following the Second Great Revival in the 1970s there has been a movement from within Sumi society to reconstruct and redefine their identity by drawing heavily on both their contemporary religion (Baptist Christianity) and their 'good' pre-Christian culture, which had been demonised and rejected in the course of earlier conversions. Discourses have been circulating in public space on the urgent need to reconceptualise collective Sumi identity by reviving, or preserving, those aspects of pre-Christian Sumi culture that are perceived as 'good' and constitutive of Sumi-ness but are currently 'under threat' of being gradually lost to modernity and foreign influences. These discourses are directly linked to processes of cultural revivalism across Nagaland, which have been motivated by a sense of the perceived loss of 'good' cultural heritage and cultural roots. This thesis is an ethnographic study of these processes of identity (re)construction within a Sumi Naga community. It sets out to examine the ways in which Baptist Christianity is central to everyday life in a Sumi village and how it plays an important role in forging group cohesion and solidarity through ritual practice and various forms of fellowship. The thesis then proceeds to study the phenomenon of cultural revivalism in both its discursive and practical manifestations. The thesis argues that the cultural revival has not reduced the centrality of Baptist Christianity to Sumi self-ascriptions and perceptions of identity, but is rather thought to have enriched it and given it a stronger cultural foundation. Hence, a Sumi Naga Christianity is being created which is perceived as unique, indigenous and distinct in its own right. The thesis attempts to explore the essence of this vernacular Christianity against the backdrop of its specific historical, economic, political and spiritual context and the all-encompassing Naga struggle against the Indian nation-state. In pursuing these issues, the thesis locates itself within debates on the intersection between religion and identity politics, which prevail in many contemporary contributions to the anthropology of Christianity.

Abstract in English, Zulu and Sepedi / The purpose of this study was to determine the impact of capital structure on the profitability of the Land and Agricultural Development Bank of South Africa (Land Bank). Both theoretical and empirical literature were reviewed in order to guide the empirical investigation of this study. In particular, the theories of financial intermediation, credit creation and fractional reserve formed the basis of this study. The capital structure theories that were examined included the pecking order theory, trade-off theory and Modigliani-Miller leverage irrelevance theory. In the literature, it was observed that profitable companies prefer using internal funds over debt or equity. To test the stated hypothesis that there is no relationship between capital structure and bank profitability, a quantitative research design with a case study approach was used, with the Land Bank as the unit of analysis. Using time series data for the period 1982 to 2015, multiple regression using the ordinary least squares method was applied to test the specified models. Preliminary data analysis was performed using trend analysis, descriptive statistics and Pearson bivariate correlation analysis. The study demonstrated that the relationship between capital structure and bank profitability was positive and statistically significant at a 95% confidence level when using only equity. However, inclusion of debt in the capital structure showed that capital structure, proxied by the debt-to-equity ratio, resulted in a negative relationship between capital structure and bank profitability, albeit statistically insignificant. It was concluded that the Land Bank requires an injection of equity to improve its performance. Alternative low-cost sources of funding to debt should be considered. The results of the study have policy implications for the Land Bank, regulators and potential investors. / Injongo yalolu cwaningo kwabe kuwukucubungula nokuthola umthelela wesimozimali sebhizinisi ekungeneni kwenzuzo eBhange Lokuthuthukiswa Komhlaba Nezolimo laseNingizimu Afrika (iBhange Lomhlaba). Kokubili, imibhalo yethiyori kanye nemibhalo esuselwe emaqinisweni abonakalayo naphathekayo, yabuyekezwa ukuze ihole futhi ilawule uphenyo olugxile emaqinisweni abonakalayo naphathekayo oluqondene nalolu cwaningo. Amathiyori ayisisekelo salolu cwaningo, ikakhulukazi, kwaba yi-financial intermediation, credit creation kanye ne-fractional reserve. Lawo mathiyori esimozimali sebhizinisi acutshungulwa abandakanya i-pecking order theory, trade-off theory kanye ne-Modigliani-Miller leverage irrelevance theory. Emibhalweni eyacutshungulwa, kwabonakala ukuthi izinkampani ezinenzuzo zincamela ukusebenzisa izimali zangaphakathi kunokusebenzisa isikweletu noma izabelokulingana (equity). Ngenhloso yokuhlola ihayiphothesisi ethuliwe yokuthi abukho ubudlelwano phakathi kwesimozimali sebhizinisi kanye nokungena kwenzuzo ebhange, kwasetshenziswa idizayini yocwaningo olukhwantithethivu ehambisana nendlela yokusebenzisa ucwaningo lwesigameko egxile ekuhlaziyweni kweBhange Lomhlaba. Ngokusebenzisa i-time series data yesikhathi esisukela kowe-1982 kuyofinyelela kowezi-2015, kwalandelwa i-multiple regression ngokusebenzisa i-ordinary least squares method ukuhlola amamodeli achaziwe. Uhlaziyo lwedatha olwandulelayo lwenziwa ngokusebenzisa uhlaziyo lwezimonkambiso (trend analysis), izibalomanani ezichazayo (descriptive statistics) kanye ne-Pearson bivariate correlation analysis. Ucwaningo lwabonisa ukuthi bukhona ubudlelwano obuphawulekayo phakathi kwesimozimali sebhizinisi kanye nokungena kwenzuzo ebhange futhi idatha yabonisa ukuthembakala okusezingeni elingama-95% uma kusetshenziswa izabelokulingana kuphela. Kodwa-ke ukufakwa kwesikweletu kwisimozimali sebhizinisi kwabonisa ukuthi isimozimali sebhizinisi, ngokusekelwa yizinga-silinganiso phakathi kwesikweletu nezabelokulinganisa, kwaholela ekutheni bungabi khona ubudlelwano obuphawulekayo phakathi kwesimozimali sebhizinisi kanye nokungena kwenzuzo ebhange, nakuba idatha mayelana nalokhu yabonisa ukungathembakali okuthile. Kwafinyelelwa esiphethweni sokuthi iBhange Lomhlaba lidinga ukuthi kufakwe izabelokulingana ngenhloso yokwenza ngcono ukusebenza kwalo. Kumele kwenziwe imizamo yokuthola eminye imithombo yezimali ehlukile futhi engambi eqolo. Imiphumela yocwaningo inemithelela ethile ephathelene nezinqubomgomo eqondene neBhange Lomhlaba, abalawuli kanye nalabo okungenzeka babe nesifiso sokutshala izimali. / Morero wa thutelo ye e be e le go laetša khuetšo ya matlotlo a kgwebo go bokgoni bja go hwetša dipoelo bja Panka ya Tlhabollo ya Naga le tša Temo ya Afrika Borwa (Land Bank). Dingwalo tša ditlhalošo tša diteori le tšeo dithutelo tša peleng di di hweditšeng di sekasekilwe go fa tlhahlo go dipoelo tša dinyakišišo tšeo di dirilwego peleng tša thutelo ye. Gabotsebotse, diteori tša mokgwa wa dipanka wa go tšea tšhelete ye e bolokilwego tša e adimiša, mokgwa wa dipanka wa go hlola dikadimo ka bontši le tsheketšo ya palophatlo ya tšhelete di bopile motheo wa thutelo ye. Diteori tša matlotlo a kgwebo tšeo di lekotšwego di akareditše teori ya mokgwa wa go kgetha methopo ya kadimo ya ditšhelete, teori ya go lekanyetša ditheko le ditefelokholego le teori ya Modigliani-Miller ya go re mokgwa wa go diriša tšhelete ye e adimilwego go bona dipoelo ga o ame boleng bja khamphani. Ka go dingwalo, go lemogilwe gore dikhamphani tše di ka hwetšago dipoelo di kgetha go diriša matlole a ka gare go ena le dikoloto goba bokaalo bjo bo šalago ka morago ga go ntšha dikoloto Go leka kakanyo ye e filwego ya gore ga go na tswalano gare ga matlotlo a kgwebo le bokgoni bja panka bja go hwetša dipoelo, tlhako ya nyakišišo ya go hwetša dikarabo go batho ka bontši ka mokgwatebelelo wa nyakišišo ye e dirilwego ka ga tiragalo e dirišitšwe, ka Land Bank bjalo ka yuniti ya tshekatsheko. Ka go diriša datha go ya ka tatelano ye e itšeng ya nako ya paka ya 1982 go iša go 2015, tlhahlobo ya tswalano gare ga mabaka a mabedi goba go feta ka go diriša mokgwa wa go fokotša palo ya disekwere e dirišitšwe go leka mehlala ye e šupilwego. Tshekatsheko ya datha ya mathomo e phethagaditšwe ka go diriša tshekatsheko ya taolelopele ya seo se tla diregago ka ditšhelete, mokgwa wa go sekaseka dipalopalo le tshekatsheko ya Pearson ya dipalo tše pedi go bona tswalano ya tšona. Thutelo e laeditše gore tswalano gare ga matlotlo a kgwebo le bokgoni bja panka go hwetša dipoelo go bile le ditlamorago tše botse le dipoelo tše di ka bago nnete ka kemo ya kgonthišo ya 95% ge go dirišwa fela bokaalo bjo bo šalago ka morago ga go ntšha dikoloto. Le ge go le bjalo, kakaretšo ya sekoloto ka go matlotlo a kgwebo go bontšhitše gore matlotlo a kgwebo, ao a laeditšwego ka tekanyo ya palomoka ya dikoloto go bokaalo bjo bo šalago ka morago ga go ntšha dikoloto, e hlotše tswalano ye e sa letelwago gare ga matlotlo a kgwebo le bokgoni bja panka go hwetša dipoelo, le ge e ka ba dipoelo tše di ka bago nnete. Go phethilwe ka go re Land Bank e nyaka koketšo ya bokaalo bjo bo šalago ka morago ga go ntšha dikoloto go kaonafatša tiro ye e swanetšwego go dirwa. Methopo ye mengwe ya tswala ya fase go dikoloto e swanetšwe go lebelelwa. Dipoelo tša thutelo di na le ditlamorago tša Molaotshepetšo wa Land Bank, balaodi le babeeletši ba ka moso. / Finance, Risk Management and Banking / M. Com. (Finance)