Ce mémoire présente trois approches différentes vers la synthèse du 3–(trans–2–nitrocyclopropyl)alanine, un intermédiaire synthétique de la hormaomycine. Cette molécule naturelle démontre d’intéressantes activités biologiques et pharmacologiques. Il est intéressant de souligner que ce dérivé donne facilement accès au 3–(trans–2–aminocyclopropyl)alanine, unité centrale de la bélactosine A. Ce composé naturel possédant lui aussi d’intéressantes propriétés biologiques, plusieurs études relationnelles structures-activités menant à des dérivés plus actifs de cette molécule ont été entreprises, démontrant l’intérêt toujours présent de synthétiser de façon efficace et optimale ces dérivés cyclopropaniques. Une méthodologie développée au sein de notre groupe de recherche et basée sur une réaction de cyclopropanation intramoléculaire diastéréosélective sera mise à profit afin d’élaborer une nouvelle voie de synthèse aussi élégante qu’efficace à la construction du 3–(trans–2–nitrocyclopropyl) alanine. En utilisant un carbène de rhodium généré soit par la dégradation d’un dérivé diazoïque, soit par la formation d’un réactif de type ylure d’iodonium, une réaction de cyclopropanation diastéréosélective permettra la formation de deux autres centres contigus et ce, sans même utiliser d’auxiliaire ou de catalyseur énantioenrichis. Ensuite, un réarrangement intramoléculaire précédant deux réactions synchronisées d’ouverture de cycle et de décarboxylation permettront l’obtention du composé d’intérêt avec un rendement global convenable et en relativement peu d’étapes. De cette manière, la synthèse formelle de la bélactosine A et de l’hormaomycine a été effectuée. Cette synthèse se démarque des autres par l’utilisation d’une seule transformation catalytique énantiosélective. / This master’s thesis presents three different approaches toward the synthesis of 3–(trans–2–nitrocyclopropyl)alanine, a key constituent of the natural product hormaomycin. This unusual compound demonstrates interesting biological and pharmaceutical activity. It is noteworthy that this unique amino acid can be readily converted to the corresponding 3–(trans–2–aminocyclopropyl)alanine, the central core of belactosin A, a natural compound exhibiting interesting biological properties. Efficient syntheses of these aminocyclopropane derivatives are of current interest since several structure-activity relationships in syntheses of belactosin A and hormaomycin analogues are currently under study in an effort to discover enhanced biological activity. A methodology developed in our research group based on a diastereoselective intramolecular cyclopropanation reaction will be used to elaborate a unique and elegant pathway to the synthesis of the 3–(trans–2–nitrocyclopropyl)alanine. By using a rhodium carbene generated either by the degradation of a diazoic derivative or by the formation of the corresponding iodonium ylide, a diastereoselective cyclopropanation reaction can be applied in the concerted elaboration of two chiral centers needed in the desired aminocyclopropanes, avoiding in this way the utilisation of chiral reagents. Following this key sequence, an intramolecular rearrangement followed by synchronous ring–opening/decarboxylation reactions will permit a convenient formation of the desired product in an acceptable overall yield and in few ensuing steps. In this manner, the formal synthesis of the hormaomycin and the belactosin A can be achieved. This synthesis is unique since it involves only one asymmetric step in the whole synthetic process.

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New Fourier transform infrared (FTIR) approaches for the quantitative determination of peroxide value (PV) and isolated trans analyses were investigated and developed. The FTIR-PV methods investigated were all based on the stoichiometric reaction of hydroperoxides and triphenylphosphine (TPP) which converts TPP to triphenylphosphine oxide (TPPO). A reference transmission cell (100 mum) method was developed based on the use of a unique TPPO absorption at 542 cm-1. This method covered PV values from 0--15 PV and was shown to be superior in accuracy and reproducibility to the standard American Oil Chemists Society (AOCS) iodometric method. Subsequently, the utility of disposable polyethylene cards, normally used only for qualitative analyses, was investigated for quantitative PV determination. A quantitative IR card method was successfully developed and shown to serve as a very simple, rapid and alternative means of carrying out PV analyses. TPP-impregnated cards were able to reproduce the transmission cell PV results to +/-1.12 PV, while the unimpregnated card was slightly more accurate (+/-0.92 PV). A third FTIR-PV method was developed specifically for the at-line monitoring of high PV fatliquors and employed a germanium attenuated total reflectance sample handling accessory. This method hinged on the use of a TPPO absorption band at 1118 cm-1, normally off scale when pathlengths of >3 mum are used, but is suited to the analysis of oils having very high PVs (>250). The successful quantitative use of the disposable polyethylene IR card to PV led to its study for the quantitative FTIR determination of the isolated trans content of fats and oils and margarines. The polyethylene card was shown to unique and useful properties, tending to inhibit fat crystallization and its inability to retain moisture. These two properties allowed trans determination to be carried out on melted, high trans fats, without heating the polyethylene substrate and also to analyze margarines

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Group I introns belong to a class of large RNAs that catalyze their own excision from precursor RNA through a two-step process called self-splicing reaction. These self-splicing introns have often been converted into ribozymes with the ability site specifically cleave RNA molecules. One such ribozyme, derived from a self-splicing Pneumocystis carinii group I intron, has subsequently been shown to sequence specifically excise a segment from an exogenous RNA transcript through trans excision-splicing reaction.The trans excision-splicing reaction requires that the substrate be cleaved at two positions called the 5' and 3' splice sites. The sequence requirements at these splice sites were studied. All sixteen possible base pair combinations at the 5' splice site and the four possible nucleotides at the 3' splice site were tested for reactivity. It was found that all base pair combinations at the 5' splice site allow the first reaction step and seven out of sixteen combinations allow the second step to occur. Moreover, it was also found that non-Watson-Crick base pairs are important for 5' splice site recognition and suppress cryptic splicing. In contrast to the 5' splice site, 3' splice site absolutely requires a guanosine.The pathway of the trans excision-splicing reaction is poorly understood. Therefore, as an initial approach, a kinetic framework for the first step (5' cleavage) was established. The framework revealed that substrate binds at a rate expected for RNA-RNA helix formation. The substrate dissociates with a rate constant (0.9 min-1), similar to that for substrate cleavage (3.9 min-1). Following cleavage, the product dissociation is slower than the cleavage, making this step rate limiting for multiple-turnover reactions. Furthermore, evidence suggests that P10 helix forms after the 5' cleavage step and a conformational change exists between the two reaction steps of trans excision-splicing reaction. Combining the data presented herein and the prior knowledge of RNA catalysis, provide a much more detailed view of the second step of the trans excision-splicing reaction.These studies further characterize trans excision-splicing reaction in vitro and provide an insight into its reaction pathway. In addition, the results describe the limits ofthe trans excision-splicing reaction and suggest how key steps can be targeted for improvement using rational ribozyme design approach.

Group I introns are catalytic RNAs capable of self-splicing out of RNA transcripts. Ribozymes derived from these group I introns are used to explore the molecular recognition properties involved in intron catalysis. New ribozyme reactions are designed based on the inherent ability of these ribozymes to perform site-specific nucleophilic attacks. This study explores the molecular recognition properties of group I intron-derived ribozyme reactions and describe a new ribozyme reaction involving molecular recognition properties previously not seen.We report the development, analysis, and use of a new combinatorial approach to analyze the substrate sequence dependence of suicide inhibition, cyclization, and reverse cyclization reactions catalyzed by a group I intron from the opportunistic pathogen Pneumocystis carinii. We demonstrate that the sequence specificity of these Internal Guide Sequence (IGS) mediated reactions is not high, suggesting that RNA targeting strategies which exploit tertiary interactions could have low specificity due to the tolerance of mismatched base pairs.A group I intron-derived ribozyme from P. carinii has been previously shown to bind an exogenous RNA substrate, splice-out an internal segment, and then ligate the two ends back together (the trans excision-splicing reaction). We now report that a group I intron derived ribozyme from the ciliate Tetrahymena thermophila can also perform the trans excision-splicing reaction, although not nearly as well as the P. carinii ribozyme.In addition, we discovered a new ribozyme reaction called trans insertion-splicing where the P. carinii ribozyme binds two exogenous RNA substrates and inserts one directly into the other. Although this reaction gives the reverse products of the trans excision-splicing reaction, the trans insertion-splicing reaction is not simply the reverse reaction. The ribozyme recognizes two exogenous substrates through more complex molecular recognition interactions than what has been previously seen in group I intron-derived ribozyme reactions. We give evidence for this new reaction mechanism composed of three steps, with intermediates attached to the ribozyme.

This thesis explores the ties between the Australian and New Zealand peak trade union organisations, the Australian Council of Trade Unions (ACTU) and the New Zealand Federation of Labour (NZFOL) and its successor, the New Zealand Council of Trade Unions (NZCTU) from 1970 to 1990. The parameters for this study define a period in which unions faced an increasingly unstable industrial relations climate and an integrating world economy as globalisation shifted priorities for government and business from the worker to the consumer. This set of circumstances challenged the leaders of the union organisations to develop and evolve their links, confirming a 'trans-Tasman union community'. Underpinned by a common labour market and models of state development the organisations sought to understand the globalising world from a joint perspective acknowledging their shared economic and industrial circumstances. This led to the development of united leadership over international issues, civil rights and trans-Tasman relations. The Australasian industrial relations models diverged in the 1980s and the ACTU and NZFOL/NZCTU reacted by transferring policy across the Tasman in an attempt to develop innovative responses to manage the rise of the New Right.

This thesis investigates the evolution of Australian and New Zealand peacekeeping operations in the Pacific through a trans-Tasman lens. Both Australian and New Zealand sources are used in order to understand the relationship and interaction between the two nations. This study has a particular focus on the Truce Monitoring Group (TMG) sent to Bougainville in late 1997. This New Zealand-led operation was the first long-term regional peace initiative of recent times, and set the stage for future regional interventions by Australia and New Zealand. The thesis also considers more broadly the subsequent involvement of Australian and New Zealand peacekeepers in the International Force in East Timor (INTERFET) and Regional Assisted Mission to Solomon Islands (RAMSI). These two later operations are considered with particular attention to lessons learnt from previous peacekeeping experiences and the changing tenor of trans-Tasman relations. Since this is a history thesis it sets the argument within a historical and historiographical framework. It seeks to identify long-term trends surrounding Australia's and New Zealand's relationship with the Pacific, defence connection and Anzac heritage. A further aim of this thesis is to investigate whether joint Australian and New Zealand peacekeeping in the Pacific revived the Anzac relationship first formed at Gallipoli. By looking at evidence taken from interviews and first-hand accounts with Australian and New Zealand participants in the TMG, INTERFET and RAMSI, this thesis argues that hallmarks of the earlier Anzac relationship did re-emerge, though in a slightly different form. The phenomenon of New Zealand's reputation as having a cultural advantage in the Pacific is explored in some detail as this is an important aspect of the Anzac relationship.

Genom att intervjua fyra personer som identifierar sig som trans har denna studie undersökt hur upplevelsen av att identifiera sig med en könsidentitet som inte överensstämmer med samhällsnormen påverkat vid valet av vad individen vill jobba med. Med utgångspunkt i queerteori och kvalitativ metod har resultatet visat att deltagarnas möjlighetshorisont influeras av diskriminering, psykisk ohälsa och den påfrestning som uppstår hos individerna av att verka i ett normativt samhälle. För dessa individer blir arbetsplatsens kultur och förståelse för behovet av acceptans och trygghet viktigare än vilken bransch individen söker sig till. Hur synlig individen vill eller orkar vara påverkar också intresset för olika yrken. Studien bekräftar att samhällets utformning begränsar vissa möjligheter till anställning för personer som identifierar sig som trans. / By interviewing four individuals who define themselves as transgender, this study has researched how identifying with a gender that does not conform to the views of normative society effects their choice of vocation. Taking queer theory as a point of departure and using a qualitative interview method the results show that the respondents’ horizon for action is limited by the influence of discrimination, mental health and the strains experiences by simply living in a normative society. Acceptance and feeling safe in the workplace therefore becomes of particular importance, more so than what profession one chooses or the tasks that such a position entails. To what extent the individual wants or has the energy to be visible in their employment affects how appealing a line of work is but society itself also limits the possibilities for certain employment positions due to identifying oneself as transgender.