Murals have been the formal visual interpretation of the cultural, social and political life of all ages. Throughout they have been consistently combined with their architectural setting, for example, in ancient Egyptian tombs, in Renaissance churches and on the external walls of buildings in Mexico in the twentieth century. This is a central feature of mural painting. However many contemporary murals do not integrate with their architectural settings, in other words, do not fulfil the site-specificity of the architectural spaces for which they were made. This means that the most important aspect that distinguishes murals from other types of painting is absent. I studied and analysed a number of murals produced in the Italian Renaissance, Baroque and Rococo as this particular period is considered to be not only one of the most significant in the history of art but also a period in which painting and architecture were very closely allied as practices. In particular the radical developments in painting of pictorial space took place along side the developments in architecture. I argue that Renaissance murals could be described, using the terminology of contemporary art, as site-specific art. By identifying the relationship between pictorial space, architectural space and compositional structure I was able to test, through my own practice, the importance of these relationships in understanding the site-specificity of the compositional structure of murals. To address the issue of sitespecificity in murals, I investigated and developed a set of compositional structures through my mural practice that could be applied in the design, execution, and teaching of contemporary mural design. I have developed the notion of a deconstructive method of mural design in which the illusory space of the mural derives its compositional structure from the architectural space in which it sited. I have applied it, tested it and refined it through the execution of a number of hypothetical and live mural commissions. I believe that the approach to the study and practice of mural design I have developed from the perspective of a practice lead researcher contributes to the furtherance of mural design as both a profession and field of study. In particular the identification of compositional structures in mural design and the proposal of a deconstructive method contributes to our understanding of what a mural is as well as current notions of site-specificity in contemporary art.

A crucial step in the biosynthesis of membrane proteins is their incorporation into the hydrophobic environment of the lipid bilayer. In eukaryotic cells this event occurs largely in concert with translation on ribosomes bound to the membrane of the endoplasmic reticulum (ER) at a site termed the ER translocon. This dynamic proteinaceous complex forms an aqueous conduit across the ER membrane and is laterally gated to allow transmembrane (TM) segments to partition into the lipid phase. In the case of polytopic membrane proteins, the coordinated release of multiple TM segments by the ER translocon is a poorly defined process and appears to be highly substratespecific. In this study, the ion channel subunit P2X2 was used as a novel model to examine themolecular details of membrane protein integration at the ER translocon. A primarily in vitro approach was taken using stable biosynthetic intermediates to simulate each stage of the membrane translocation and integration of P2X2. Chemical and photoreactive site-specific cross-linking analyses were then conducted to determine the molecular environment of the P2X2 TM segments throughout biosynthesis. Remarkably, both TM1 and TM2 of P2X2 were found to remain directly adjacent to the ER translocon throughout P2X2 biosynthesis and were only dislocated into the lipid phase by artificial termination of translation and disruption of the ribosome-translocon interaction. Retention of P2X2 TM1 at the ER translocon is maintained despite the synthesis of over 300 amino acid residues separating it from the ribosome peptidyl transferase centre. Premature dislocation of TM1 from the ER translocon site resulted in a pronounced aggregation of TM1 fragments both in vitro and in vivo. This is in stark contrast to previous passive-partitioning models of membrane integration and suggests that the ER translocon regulates the integration of polytopic membrane proteins in order to accommodate the specific requirementsof the substrate protein itself. The detailed characterisation of P2X2 biosynthesis was then exploited in order to examine the effect of a novel small inhibitor of ER translocon function. Eeyarestatin 1 (ESI) was found to cause a substantial inhibition of protein secretion in vivo and dramatically reduced the ER translocation of three distinct classes of substrate, including P2X2, in vitro. Using both a cross-linking analysis and a protease-protection assay for a specialised translocation reaction, ESI was shown to prevent the transfer of the nascent polypeptide chain from the membrane delivery machinery to the ER translocon complex. Further evidence that ESI targets the Sec61 complex is presented and a model for ESI-mediated inhibition of ER translocation is suggested. Taken together these data establish ESI as a novel small molecule inhibitor that selectively inhibits protein translocation both in vitroand in vivo.

Trypanosoma brucei is a protozoan parasite that is the causative agent of sleeping sickness in sub-Saharan Africa. T. brucei has a complex life cycle involving passage between a mammalian host and the tsetse fly. The parasite evades the mammalian immune system via expression of Variant Surface Glycoprotein (VSG) on the cell surface. VSG genes are expressed at telomeric expression sites and at these sites are a number of Expression Site Associated Genes (ESAGs). One unusual ESAG, ESAG9, is developmentally regulated: RNA for these genes accumulates during the transition from slender to stumpy cells in the mammalian bloodstream and cellassociated protein is only detected transiently in stumpy and differentiating cells. Transgenic cell lines were generated which ectopically express one or more members of the ESAG9 gene family. Biochemical and cytological analyses using these cell lines indicated that some members of this family are glycosylated and GPI-anchored, and also that one gene, ESAG9-K69, is secreted. ESAG9-K69 is also secreted by wild-type stumpy parasites. In vivo experiments with tsetse flies did not conclusively show whether ESAG9 proteins play a role in the establishment of a tsetse fly mid-gut infection by transgenic trypanosomes. However, In vivo and ex vivo experiments using the mouse model of trypanosomiasis indicated that expression of ESAG9 proteins may alter parasitaemia in the mouse and results in a significant decrease in the proportion of CD4+ T cells in the mouse spleen.

Like its ancestral disciplines, archaeology is no stranger to human conflict. Greek and Roman warfare often resulted in the sacking of cities, with all property (public, private, temple) taken as booty and the population and heritage exterminated or absorbed (men killed, women and children sold into slavery). In addition to the personal danger risked in a hostile region, archaeologists may also be thrust into deep and divisive cultural embattlements. Cultural property may be destroyed, intentionally or unintentionally. Graves, including potential evidence of genocide or mass murder, may be disturbed. Archaeologists may find themselves embroiled in many of these disputes and violent events, leading to difficult and complex ethical issues. This viperous nest of ethical concerns is amplified where an archaeologist is present as part of, or perceived to be related to, an invading or occupying military force. The goal of this thesis is to develop an engaging and pragmatic virtue-based professional ethic that may guide an archaeologist and archaeology through the ethical bramble bush raised by modern human conflict. The present ethical systems, based primarily on utilitarian or deontological principles manifested in ethical codes, are deficient because they fail to establish the archaeologist as a trustee (active or passive) in a political dynamic, elevate the archaeological record even when these professional codes purport to discount its importance, fail to address adequately the matrix of relationships in a manner that ensures trust across the interests of all stakeholders – both present and past, and dramatically fail to identify and develop the central thrust of a professional ethic (as opposed to personal moral judgment) in the first instance.

Master of Arts in Fine Arts - Fine Arts / A Community Partnership Art Event, resulting from curating and facilitating an educational collaboration was held on the 23 March 2004, ten years into South Africa’s democracy. Through a Masters in Fine Arts coursework entitled “Creating, Curating and Critiquing” offered at the University of Witwatersrand, I attempted to test the boundaries of the Arts and Culture Learning Area and explore alternatives to the current definition of “outreach”. The grade six learners from The Ridge School, an independent boys’ preparatory school and Salvazione Christian School, an assisted government school, were brought together over a period of ten weeks during regular school art lessons. Through the guidance and expertise of various artists, workshops were cocoordinated with the collaborative ideas of the learners coming to the fore. The process and dialogue established between learners, artists and educators was intended to shift my own parameters of teaching primary school art. Focusing on people rather than the final products points to a readiness to view knowledge not as a commodity owned b#31;#31;the expert teacher, but rather as something which can be constructed and developed with the learners. Originally the collaboration was intended as a celebration of the opening of new premises for Salvazione Christian School. The public art happening was held in a tent next to the informal settlement where a large majority of the children from Salvazione Christian School live. 3 Rather than what might be described as a modernist approach to art education, where the focus seems to be on the artist and artwork, the focus was on linking art to social interaction, and it was through the discovery of a form of hybridity that a number of differences between the two communities were challenged and exposed. This resulted in an approach that seems similar to the manner in which the Indian writer, Salman Rushdie writes of hybridity: “Hybridity, impurity, intermingling, the transformation that comes of new and unexpected combinations of human beings, cultures, ideas, politics, movies, songs.” (Coombes, 2000:39) Through this hybridity tensions were created and explored rather than a ‘rainbow’ or melting pot created, where differences are glossed over as in a multicultural approach. The primary research methodology was participant observation in which directly observed data was analyzed and interpreted. Data was gathered from the interactions in the workshops, setting up the exhibition and the art event. As intended, a link between art and ‘outreach’ was established. In order for this link to change into a community partnership, it must be seen as part of a much longer process. The process as a whole did become a different kind of primary school art space, preparing the way for possible positive transformation of the visual arts in the arts and culture learning area at primary school level.

The site analysis and mapping methods in the design and planning professions follow a standardized quantitative and qualitative analyis of place that favors a design process which can limit creativity and render it difficult to do anything with the normative. This work is an exploration of the development of a design approach and method that uses voice mapping as a basis for design. The voice maps contain oral histories and personal accounts of landscape experiences. Voice mapping is employed not only as a method or for site analysis but also as a generator or ideas. Voice Map Trekking is explored through a trek in the Canadian Arctic and across the Canadian Prairies. Two specific landscapes were chosen as bases for testing concepts - one near St. Gertrude SK and the other near Morinville AB. / February 2008

Utilising previously unpublished ceramic evidence from the important Late Cypriot settlement of Enkomi, this thesis focuses on the impact on Cypriot social organisation of increased involvement with the complex societies of the eastern Mediterranean at the beginning of the Late Cypriot period, c. 1650 BCE. The main focus is on one aspect of the material culture: the first appearances of wheelmade pottery and the relationship of the wheelmade ceramics to the remainder of the assemblage. The introduction of wheelmade pottery has long been seen as a component of the 'social complexity package' and considered to be indicative of highly complex societies, along with full-time specialisation and mass production. The ceramic and settlement evidence from Enkomi is addressed in detail to evaluate the degree of social complexity present for the initial stages of settlement transformation on Cyprus from MCIII-LCIIB, prior to the appearance of urban centres during LCIIC. The extent of excavation at Enkomi, compared to other sites of the period, and the wealth of finds from both mortuary and settlement contexts has led to assumptions about the site's relative importance to the processes of change occurring on Cyprus. The notion of Enkomi as a pre-eminent town or as an archaic state is questioned in relation to the evidence from other settlements. The thesis is divided into four parts. Part 1 discusses the theoretical background for social complexity and outlines the explanatory models which have been developed for the Late Cypriot. I address the importance of trade, and briefly outline the modes of contact and social organisation in the eastern Mediterranean region in order to provide a framework for the interaction of Cyprus within this sphere. I also discuss the significance that has been placed on the appearance of wheel made ceramics in archaeological assemblages. The identification of wheel made ceramics is more complex than is often assumed and an important distinction should be made between pottery with the superficial appearance of being wheelmade and pottery that is actually wheelmade. Part 2 assesses the evidence of ceramics and settlement from other early LC sites in order to investigate whether Enkomi may be considered to have played a dominant role on the island in terms of site hierarchy or control over resources. A brief summary of the evidence of the ceramic and settlement evidence for the EC-MC and the LCllC-lllA periods is provided for comparative purposes. In Part 3 the Enkomi settlement and ceramic evidence is considered in detail. The combined evidence indicates a more complex sequence of construction, occupation and abandonment than has been assumed. Additionally, the adoption of wheelmade pottery is found to be a sporadic and gradual process, with the handmade and wheelmade versions of the ceramic wares manufactured concurrently from LCl-LCIIB. The conclusions reached are presented in Part 4. The processes by which Cyprus came to play an important role within the trading networks of the Late Bronze Age are more complex and gradual than generally acknowledged. A combination of settlement and ceramic evidence indicates that social organisation during LCI remained small-scale with regional traditions persisting and limited influence between the emergent polities on the island. During LCllA-B, the degree of intra-island contacts increased and a uniform material culture is adopted, developing into a series of highly structured urban polities by LCIIC. It does not appear likely that any site or region exercised islandwide control during LCI and the autonomous polities of LCIIC therefore represent a continuation of the social organisation from the preceding periods, rather than a devolution of centralised control.

KplE1 est l’un des dix prophages présents sur le chromosome de la souche Escherichia coli K12. Nous avons montré in vivo que ce prophage est compétant pour s’exciser du chromosome bactérien bien qu’il soit incapable de former des particules virales et de lyser son hôte. Au laboratoire, nous avons identifié les protéines IntS (intégrase) et TorI (RDF), codées sur le prophage KplE1, et la protéine IHF (NBP) de l’hôte comme seules impliquées dans le mécanisme de recombinaison spécifique de site (RSS). Nous avons cartographié sur les régions attL et attR, les sites de fixations des protéines de recombinaison permettant l’assemblage de l’intasome, le complexe nucléoprotéique compétant pour la RSS. L’ensemble de ces sites ainsi que les gènes intS et torI qui chevauchent respectivement les régions attL et attR, ont permis de définir un module de recombinaison de type KplE1. Ce module est très conservé et se retrouve chez des phages infectant différentes souches d’E. coli et de shigella. Le modèle en terme de RSS est celui décrit pour les bactériophages de type λ. Cependant, le nombre et l’organisation des sites de recombinaison suggèrent que l’architecture de l’intasome de type KplE1 diffère de celle de λ. Nos résultats renforcent ainsi l’idée que l’assemblage de l’intasome est spécifique du module de RSS considéré même si, in fine, la réaction catalysée demeure similaire.En ce qui concerne l’expression des gènes intS et torI, le fait que ces gènes soient localisés à chacune des extrémités du prophage, rend ainsi impossible leur couplage transcriptionnel à partir d’un promoteur commun au moment de la commutation lyse/lysogénie, tel qu’il est connu pour les phages lambdoïdes. De part son orientation atypique sur attL, la présence de sites de fixations des protéines IntS et TorI au niveau du promoteur du gène intS, nous ont logiquement amené à étudier sa régulation. Nous avons ainsi montré que le gène intS est négativement régulé par son propre produit ainsi que par la protéine RDF TorI. Nos résultats in vivo et in vitro indiquent que l’efficacité de la réaction de recombinaison excisive est intimement liée à la quantité d’intégrase présente, pouvant alors justifier la raison d’être de ce contrôle strict de l’expression du gène intS. En parallèle, une approche in silico a révélé que cette orientation atypique du gène codant pour l’intégrase est largement répandue sur les génomes des prophages, nous amenant à généraliser ce mécanisme atypique de régulation négative de l’intégrase. / KplE1 is one of the 10 prophage region present on the Escherichia coli K12 chromosome. We showed in vivo that this prophage is fully competent to excise from the bacterial chromosome, although it is unable to form viral particles and lyse its host. In the laboratory, we have identified Ints (integrase) and TorI (RDF) proteins, encoded on the KplE1 prophage, and the host protein IHF (NBP) only involved in the mechanism of site-specific recombination (SSR). We have mapped on attL and attR regions, the binding sites of recombinant proteins for the assembly of the intasome, the nucleoprotein complex competent for SSR. All of these sites as well as intS and torI genes that overlap respectively attL and attR regions, have permit to define a KplE1 recombination module. This module is highly conserved and is found among phages infecting different E. coli and shigella strains. The model in terms of RSS is that described for λ bacteriophage. However, the number and organization of recombination sites suggests that the architecture of the KplE1 intasome differs from that of λ. Our findings reinforce the idea that the intasome assembly is specific to the SSR module considered even if ultimately the catalyzed reaction is similar.Regarding the intS and torI gene expressions, the fact that these genes are located at each end of the prophage, prevented the transcriptional coupling of these genes from a common promoter when the lysis/lysogeny switch occurs. Because of its atypical orientation on attL, and the presence of IntS and TorI protein binding sites that overlap its promoter region, we have logically studied the regulation of the intS gene. We have shown that intS is negatively regulated by both IntS and TorI proteins. Our in vivo and in vitro results suggest that the efficiency of the excision recombination reaction is closely related to the amount of this integrase, which can justify the strict control of the intS gene expression. In parallel, an in silico approach has revealed that the atypical orientation of the integrase gene is widespread in prophage genomes, leading us to generalize this atypical mechanism of negative regulation of integrase

FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1) proteins share highly conserved amino acid residues but they play opposite regulatory roles in promoting and repressing the flowering response, respectively. Previous substitution models and functional analysis have identified several key amino acid residues which are critical for the promotion of flowering. However, the precise relationship between naturally occurring FT/TFL1 homologs and the mechanism of their role in flowering is still unclear. In this study, FT/TFL1 homologs from eight Rosaceae species, namely, Spiraea cantoniensis, Pyracantha fortuneana, Photinia serrulata, Fragaria ananassa, Rosa hybrida, Prunus mume, Prunus persica and Prunus yedoensis, were isolated. Three of these homologs were further characterized by functional analyses involving site-directed mutagenesis. The results showed that these FT/TFL1 homologs might have diverse functions despite sharing a high similarity of sequences or crystal structures. Functional analyses were conducted for the key FT amino acids, Tyr-85 and Gln-140. It revealed that TFL1 homologs cannot promote flowering simply by substitution with key FT amino acid residues. Mutations of the IYN triplet motif within segment C of exon 4 can prevent the FT homolog from promoting the flowering. Furthermore, physical interaction of FT homologous or mutated proteins with the transcription factor FD, together with their lipid-binding properties analysis, showed that it was not sufficient to trigger flowering. Thus, our findings revealed that the divergence of flowering time modulating by FT/TFL1 homologs is independent to interaction and binding activities.

M.Sc. (Botany) / Global efforts to protect the world’s forests from unsustainable and inequitable exploitation have been undermined in recent years by rampant illegal logging in many timber-producing countries. A prerequisite for efficient control and seizure of illegally harvested forest product is a rapid, accurate and tamper proof method of species identification. DNA barcoding is one such a tool, relatively simple to apply. It is acknowledged to bring about accuracy and efficiency in species identification. In this study a DNA barcode reference library for traded and protected tree species of southern Africa was developed comprising of 81 species and 48 genera. Four primary analyses were conducted to assess the suitability of the core barcodes as a species identification tool using the R package Spider 1.2-0. Lastly, to evaluate this identification tool, query specimens independently sampled at a Mozambican logging concession were identified using DNA barcoding techniques. The nearest neighbour (k-NN) and best close match (BCM) distance based parameter yielded 90% and 85% identification success rate using the core plant barcodes respectively. DNA barcoding identification of query specimens maintained a constant 83% accuracy over the single marker dataset and the combined dataset. This database can serve as a backbone to a control mechanism based on DNA techniques for species identification and also advance the ability of relevant authorities to rapidly identify species of timber at entry and exit points between countries with simple, fast, and accurate DNA techniques.