The growing level of credit extension in South Africa has received a lot of attention recently, more so as household debt, as a percentage of disposable income, tests record highs. It has been argued that this growth in household debt has been driven by ease of access to credit, with authorities going so far as to suggest that lenders have been extending credit ‘recklessly’. The National Credit Act was enacted on the premise that consumers need to be protected from this practice. The Act thus exerts pressure on the credit lenders to assess the consumer’s ability to repay, disclose the cost of credit, as well as setting limit on interest that can be charged. The aim of the research is to investigate the effectiveness of the Act in curbing consumer indebtedness and how it can lead to consumer behavioural attitudes and actions toward credit use. The research was carried out in two stages. The purpose of the first phase sought to explore the effectiveness of the Act by consulting with those charged with supervision of the Act (the regulator) and those implementing the Act (credit providers), while the second phase conducted a survey amongst consumers to establish their levels of awareness and understanding of the Act, and how they would model their behaviours differently, so as to curb their indebtedness. The results derived from the research show that an overwhelming acceptance of the Act, its intentions and desired outcomes amongst credit provider and the regulator, and the general need for consumer protection. Consumers, on the other hand indicate a low level of awareness of the Act, its intentions and how it is likely to impact on their finances, making it difficult to tell if it can lead to changes in levels of consumer indebtedness. / Dissertation (MBA)--University of Pretoria, 2010. / Gordon Institute of Business Science (GIBS) / unrestricted

Due to the ineffectiveness of previous credit consumer legislation to deal with the demands of a complex consumer market, a need for legislative reform in this area arose in South Africa. The National Credit Act was introduced to create a single system to regulate credit and to address the shortcomings of the previous consumer credit legislation. The Act came into full force and effect on 1 June 2007. it has a wider field of application that its predecessors and offer greater protection to consumers who enter into credit agreements with credit providers. The Act applies to all credit almost all credit agreements between parties dealing at arm's length and made, or having an effect within the Republic of South Africa, subject to certain exclusions. Three main categories of credit agreements can be identified in the Act. They are credit facilities, credit transactions and credit guarantees. The second main category also has sub-categories of agreements which are also defined in the Act. It is sometimes difficult to distinguish between the different credit agreements but it remains important since different rules apply in respect of each credit agreement. In order to distinguish a credit agreement from another, it is important to look at the elements of each definition closely and to identify characteristics which are unique to that specific agreement. It is widely accepted that every credit agreement contains two essential elements. Firstly there has to be a deferral of payment by the credit provider in respect of a debt owed by the consumer and secondly the credit provider charges a fee or interest in respect of the deferred payment. It is interesting in this regard that some of the definitions in the Act do not require a fee or interest to be levied such as in the case of a mortgage agreement or a secured loan. Coincidentally, these two definitions are also problematic in the sense that they introduce concepts which are not recognised in our legal system, it will be interesting to see what our courts make of these concepts and how they will go about incorporating it into the general principles of South African law. The different agreements to which the Act applies and their irregularities will be discussed and critically analysed. Copyright / Dissertation (LLM)--University of Pretoria, 2012. / Private Law / unrestricted

The credit industry in South Africa has grown exponentially over the past two decades. Previously the industry was regulated by different Acts that had to be interpreted jointly, and while there was an overlap between them they also differed. The dual implementation made consumer credit an extremely difficult and confusing environment, especially for the consumer. Global movement towards socio-economic type legislation and in an effort to bring a solution to the eminent credit crisis resulted in new consumer protection law. Enacted on 10 March 2006 and phased in stages over a 12 month period from 1 June 2006 till 1 June 2007 the National Credit Act has a wider field of application than any of its predecessors, bringing with it a single platform for consumer credit regulation. The management of the credit relationship between the credit provider and the consumer is largely by agreement or in other words contract. The National Credit Act to a considerable extent codifies this relationship. The NCA applies to every credit agreement between parties dealing at arm’s length and made within, or having an effect within, the Republic. This definition is subject to limitations and the exclusions. The way in which the NCA defines its field of application may differ from its predecessors and even common law. The Act defines three main types of credit agreements namely credit facilities, credit transactions and credit guarantees. Credit transactions also consist of eight subcategories. It is critical to distinguish between these different credit agreements and the manner in which the Act defines them must be scrutinised. This is not only important to determine if a certain agreement is a credit agreement in terms of the National Credit Act, but also if the Act applies, to what extent. Unfortunate grammatical construction and word choice by the legislator does not assist in this task. How the Act defines its field of application in relation to the types of agreement it applies to will be critically discussed and analysed. / Dissertation (LLM)--University of Pretoria, 2014. / Private Law / unrestricted

No abstract available / Dissertation (LLM)--University of Pretoria, 2013. / lmchunu2014 / Mercantile Law / unrestricted

No abstract available / Dissertation (LLM)--University of Pretoria, 2012. / Mercantile Law / unrestricted

Various synthetic approaches were explored towards the preparation of poly(N-substituted glycine) homo/co-polymers (a.k.a. polypeptoids). In particular, monomers that would facilitate in the preparation of bio-relevant polymers via either chain- or step-growth polymerization were targeted. A 3-step synthetic approach towards N-substituted glycine N-carboxyanhydrides (NNCA) was implemented, or developed, and optimized allowing for an efficient gram scale preparation of the aforementioned monomer (chain-growth). After exploring several solvents and various conditions, a reproducible and efficient ring-opening polymerization (ROP) of NNCAs was developed in benzonitrile (PhCN). However, achieving molecular weights greater than 7 kDa required longer reaction times (>4 weeks) and sub-sequentially allowed for undesirable competing side reactions to occur (eg. zwitterion monomer mechanisms). A bulk-polymerization strategy provided molecular weights up to 11 kDa within 24 hours but suffered from low monomer conversions (ca. 25%). Likewise, a preliminary study towards alcohol promoted ROP of NNCAs suffered from impurities and a suspected alternative activated monomer mechanism (AAMM) providing poor inclusion of the initiator and leading to multi-modal dispersed polymeric systems. The post-modification of poly(N-allyl glycine) via thiol-ene photo-addition was observed to be quantitative, with the utilization of photo-initiators, and facilitated in the first glyco-peptoid prepared under environmentally benign conditions. Furthermore, poly(N-allyl glycine) demonstrated thermo-responsive behavior and could be prepared as a semi-crystalline bio-relevant polymer from solution (ie. annealing). Initial efforts in preparing these polymers via standard poly-condensation protocols were insufficient (step-growth). However, a thermally induced side-product, diallyl diketopiperazine (DKP), afforded the opportunity to explore photo-induced thiol-ene and acyclic diene metathesis (ADMET) polymerizations. Thiol-ene polymerization readily led to low molecular weight polymers (<2.5 kDa), that were insoluble in most solvents except heated amide solvents (ie. DMF), whereas ADMET polymerization, with diallyl DKP, was unsuccessful due to a suspected 6 member complexation/deactivation state of the catalyst. This understanding prompted the preparation of elongated DKPs most notably dibutenyl DKP. SEC data supports the aforementioned understanding but requires further optimization studies in both the preparation of the DKP monomers and following ADMET polymerization. This work was supported by NMR, GC-MS, FT-IR, SEC-IR, and MALDI-Tof MS characterization. Polymer properties were measured by UV-Vis, TGA, and DSC. / Die Annehmlichkeiten des Alltags und das hohe Alter das Menschen in der heutigen Zeit erreichen sind ein Ergebnis des wissenschaftlichen und technologischen Fortschritts. Insbesondere in der Medizin haben die Entwicklung neuartiger Medikamente und Therapien, künstlicher Knochen und Gewebeteile sowie der Einsatz von neuen Geräten für die Diagnostik und Assistenz bei Operationen enorm zu diesen Errungenschaften beigetragen. Jede Entwicklung fundierte letztlichen auf den Ergebnissen der Grundlagenforschung sei es von Mikro-/biologen (Identifikation anormalen Verhaltens), Biochemikern (Identifikation von Auslösern und Wirkzentren) Bio-/ organischen Chemikern (Synthese von Makro-/molekülen), Material-/chemikern (Materialsynthese) und/oder Ingenieuren/Mathematikern/Physikern (theoretischen Modelle und Berechnungen). Biomedizinische Anwendungen wie z.B. Biosensoren, künstliche Gewebeteile und Trägersubstanzen zur gezielten Wirkstofffreisetzung sind von besonderem Interesse. Materialien, die nach Kontakt mit einer Zelloberfläche in der Lage sind definiert ihre Struktur oder mechanischen Eigenschaften zu verändern und anschließend bioabbaubar sind ohne toxische Nebenwirkungen zu entfalten befriedigen die zuvor genannten Bedürfnisse. Organismen entwickeln Biomaterialien bereits seit Millionen von Jahren und sind daher ein typischer Startpunkt für die Inspiration zu vielversprechenden Substanzen. Peptoide, als Mimetika von Peptiden, werden bereits längerem von Bio-/chemikern synthetisiert und auf ihren therapeutischen Nutzen hin, neuerdings auch auf ihre Materialeigenschaften untersucht. Grundlegende Eigenschaften dieser Materialien sind ihre Biokompatibilität, kontrollierte Bioabbaubarkeit, thermische Prozessierbarkeit sowie ihre Fähigkeit zur Selbstorganisation in höher geordnete Strukturen. Die sequenzdefinierte Synthese ist jedoch aufwendig und teuer. In dieser Arbeit habe ich ein alternatives Herstellungsverfahren (Ringöffnungspolymerisation) entwickelt mit dem es möglich ist hochmolekulare Substanzen - genannt poly(N-substituierte Glycine) – herzustellen. Ich erwarte, dass diese Materialien ähnliche stimulus responsive und thermische Eigenschaften wie Polypeptide, die bereits intensiv auf ihre biomedizinische Anwendbarkeit untersucht werden, haben. Im Vergleich zu den strukturgleichen Peptiden erwarte ich eine höhere Biokompatibilität sodass diese Materialen eine vielversprechende neue Klasse biorelevanter Materialien darstellen könnte. Die fundamentalen Ergebnisse dieser Arbeit stellen eine Alternative zu den bekannten Methoden zur Herstellung poly(N-substituierter Glycine) dar. Selbige weisen stimulus responsives Verhalten und thermische Prozessierbarkeit auf, das vergleichbar ist mit bereits bekannten Materialien. Darüber hinaus erlauben sie die einfache und vielseitige Funktionalisierung für vielschichtige Anwendungen.

De part leurs nombreuses activités biologiques et leur propriétés physicochmiques et structurales, les peptides présentent un intérêt considérable pour la conception de molécules actives mais aussi pour l'élaboration de biomatériaux. Pour lutter contre l'alopécie (perte de cheveux) et la canitie (blanchiment des cheveux), nous avons axé nos travaux sur la recherche de peptides bioactifs. Pour cela, nous avons identifié des peptides têtes de série provenant soit de la littérature soit d'un criblage réalisé par l'institut européen de biologie (IEB). Ces peptides têtes de séries ont été modifiés afin d'améliorer leur activité et leur biodisponibilité tout en tenant compte du mode d'administration par voie topique. Lors de ce travail, nous avons également développé deux nouvelles méthodologies permettant la polymérisation de séquences peptidiques. En effet, les polymères à base de peptide présentent un intérêt majeur pour des applications en biotechnologie (tissus artificiels, implants), ou comme systèmes de transport ou de délivrance de principes actifs. Nous avons notamment mis au point la polymérisation de peptides hybrides présentant des fonctions dimethylsilanol ainsi que la polymérisation par ouverture du cycle de N-carboxyanhydrides portant une séquence peptidique. Ces deux stratégies ont permis d'obtenir des polymères linéaires ou en peigne. / Because of their numerous biological activities and their structural and physico-chemical properties, peptides are of considerable interest for the design of active molecules but also for the development of biomaterials. To fight against alopecia (hair loss) and canities (whitning hair), we focused our attention on the research of bioactive peptides. In this context, we have identified leads peptides either from the literature or from a screening conducted by the European Institute of Biology (IEB). These Leads were modified to improve their activity and bioavailability knowing that they will be applied topically. In this work, we have also developed two new methodologies for the polymerization of peptide sequences. Indeed, peptide-based polymers are of major interest for applications in biotechnology (i.e. artificial tissue,implants), or as systems of transport and delivery of drug. The first methodology relies on the polymerization of the hybrid peptides displaying dimethyl hydroxysilane functions. The other one involves the ring opening polymerization of N-carboxyanhydrides bearing a peptide sequence. Both strategies were used to obtain linear or comb peptide-polymers.

This thesis is about the phase transformation, shape, size distribution and coalescence of TiO2 (part I) and ZrO2 (part II) nanopartilces produced by Nd-YAG laser ablation on metal targets under oxygen background gas, and characterized by analytical electron microscopy. The optimum laser ablation condition that satisfactory and routinely yield high-pressure phases of TiO2 (i.e. £\-PbO2-type and fluorite-related structures) and ZrO2 with high residual stress were reported. Part I-1 focuses on physical coagulation, by Van der Waals force, of the TiO2 condensates at temperatures up to about 1000 K as a result of post-condensation radiant heating. In part I-2, imperfect oriented attachment of nanoparticles over specific surfaces is rationalized to cause accretion and defects for the rutile condensates. Brownian motion may proceed above a critical temperature for anchorage release at the interface of imperfect attached nanoparticles until an epitaxial relationship is reached. Part I-3 deals with further the Brownian-type rotation of the imperfectly impinged £\-PbO2-type TiO2 and rutile nanocondensates until interfacial-energy cusp was reached. In part I-4 laser ablation condensation synthesis of dense TiO2 polymorphs and their phase transformations were documented. Part II-1 is about dense tetragonal (t)-ZrO2 and cubic (c-) nanocondensates which were synthesized under very rapid heating and cooling by pulsed Nd-YAG laser ablation with oxygen background gas. The t-ZrO2 nanoparticles were found to form deformation twins/faults and followed unique transformation path upon local electron dosage. Electron diffraction indicated that the dense c- and t- phase with specific size and residual stress were allowed to relax and/or kinetically phase change into lower-energy state as constrained by the intersections of the internal energy vs. cell volume plots calculated for the two polymorphs (Part II-2).

NCA-1 (putative nematode calcium channel) and NCA-2 are two cation channel-like proteins in Caenorhabditis elegans that function redundantly to regulate locomotion through unknown mechanisms. A recent study from our lab showed that in vivo Ca2+ imaging analyses of egg-laying neurons in nca-1 loss- and gain-of-function mutants implicate that NCA channels regulate Ca2+ flux at synapses, without affecting Ca2+ dynamics in neuron somas. Furthermore, we observed that NCA-1 localizes to non-synaptic region along axons, strongly suggesting that NCA channels propagate electrical signals from cell bodies to synapses. To identify molecular components that function in the nca-1 genetic pathway, I performed a genetic suppressor screen that led to the identification of behavioral suppressors of nca-1 gain-of-function mutant. Possible NCA auxiliary subunits, UNC-79 (uncoordinated) and UNC-80, were identified from this screen. Molecular characterization of other suppressors will help to identify other regulators and downstream signaling components through which NCA channels transmit electrical signals.

NCA-1 (putative nematode calcium channel) and NCA-2 are two cation channel-like proteins in Caenorhabditis elegans that function redundantly to regulate locomotion through unknown mechanisms. A recent study from our lab showed that in vivo Ca2+ imaging analyses of egg-laying neurons in nca-1 loss- and gain-of-function mutants implicate that NCA channels regulate Ca2+ flux at synapses, without affecting Ca2+ dynamics in neuron somas. Furthermore, we observed that NCA-1 localizes to non-synaptic region along axons, strongly suggesting that NCA channels propagate electrical signals from cell bodies to synapses. To identify molecular components that function in the nca-1 genetic pathway, I performed a genetic suppressor screen that led to the identification of behavioral suppressors of nca-1 gain-of-function mutant. Possible NCA auxiliary subunits, UNC-79 (uncoordinated) and UNC-80, were identified from this screen. Molecular characterization of other suppressors will help to identify other regulators and downstream signaling components through which NCA channels transmit electrical signals.