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Exploring natural yeast diversity for high protein secretion
No full textEmpirical thesis.Bibliography: pages 42-45.Chapter One. Introduction -- Chapter Two. Materials and methods -- Chapter Three. Results and discussion -- Chapter Four. Conclusions -- References -- Supplementary material.Ethanol is seen as a sustainable biofuel, reducing reliance on non-sustainable fossil fuels. Cellulose is an abundant component in agricultural waste and is composed of glucose, linked by β-1,4-glycosidic bonds. If this waste biomass could be utilised as a potential source of glucose for fermentation to ethanol, it would lower production costs. However, cellulose is recalcitrant to enzymatic hydrolysis, requiring high enzyme levels for efficient sugar liberation. In this project, the natural variation of divergent Saccharomyces cerevisiae isolates was utilised to identify high heterologous cellobiohydrolase secreting strains. In preparation for quantitative trait loci identification, 18 haploid S. cerevisiae strains were generated from these isolates. Expression cassettes were constructed to allow the single copy integration and expression of two closely related cellobiohydrolase genes from Rasamsonia emersonii (Te) and Trichoderma reesei (Tr), and the ability of each of the 18 haploid strains to secrete the two cellobiohydrolases was evaluated. There were distinct secretion phenotypes between different strains secreting the same CBH1, with up to a 5-fold difference between the lowest and highest secretors. These high secretion phenotypes resulted in the identification of different strains efficient at secreting either the Te or Tr CBH1. Strains with superior secretion characteristics were combined with reference strains, and representative high secreting progeny were selected for downstream beneficial allele identification.1 online resource (49 pages) colour illustration
The neurological examination in adults with autism spectrum conditions: a pilot study
No full textEmpirical thesis.Bibliography: pages 50-71.Chapter 1. Introduction -- Chapter 2. Background -- Chapter 3. Methods -- Chapter 4. Results -- Chapter 5. Discussion.Autism is a neurodevelopmental condition. However, the way neurological aspects of autism persist into adulthood and old age is not well understood. Neurological disorders are the second highest cause of mortality in adults with autism, the highest being suicide. A primary care clinician uses the neurological examination (neuroexam) as the first port of call to assess neurological function. The neurodevelopmental nature of autism begs the question of how useful the standard physical examination is in assessing neurological health or pathology in adults with autism.The study had two objectives: to assess the feasibility of the neuroexam protocol and the tolerability of the neuroexam to participants with autism, and to assess the results of the neuroexam for between group differences.The present study recruited 17 participants, aged 18 – 30 years, to attend a neuroexam. Seven participants had a diagnosis of autism, whilst the other ten were typically developed participants as controls.The neuroexam was well tolerated by all participants. The protocol revealed some problems in the application of the graphaesthesia and timed motor coordination tests but otherwise ran smoothly. The neuroexam results displayed significant differences between groups in cranial nerves, and motor coordination and balance. Individual tests which were significant included: saccades, muscles of facial expression, finger-to-nose, and pronation/supination.Mode of access: World wide web1 online resource (vi, 71, 2 pages) table
“For an authentic democracy, #IAm132”: contested democratic imaginaries in the Mexican student movement, #YoSoy132
No full textTheoretical thesis.Bibliography: pages 246-274.Introduction -- Chapter 1. (Re)conceptualising #YoSoy132 -- Chapter 2. Legacies of struggle -- Chapter 3. The encounter -- Chapter 4. A new political style -- Chapter 5. Bifurcation -- Chapter 7. An authentic democracy -- Chapter 7. Lasting significance -- Conclusion -- References -- Appendix.#YoSoy132 erupted unexpectedly during Mexico’s 2012 presidential elections in the face of the imminent return of the ex-hegemonic Institutional Revolutionary Party (PRI) to power. Faced with this threat to Mexico’s weakly consolidated democracy and with the candidate’s neoliberal reforms package, this volatile student movement temporarily united sections of a deeply divided student body. Given the entrenched class antagonisms that divide public and private universities in Mexico, surprisingly little critical attention has been paid to the forging of these political solidarities. Instead the literature has emphasised the aesthetic self-consciousness and innovative use of new communication technologies as mechanisms for contesting power and alternatives for participation. Such accounts sideline socio-economic and historical factors in favour of cultural and communicative analyses of the movement’s politics, overlooking factors that mediate access and influence. This thesis grounds the ongoing significance of #YoSoy132 within a history of democratising struggles in Mexico. Drawing on 21 semi-structured interviews, I explore participant reflections two years on, at the movement’s epicentre: Mexico City. Investigating the play of competing democratic imaginaries within the movement, I argue that a new political style enabled #YoSoy132 to temporarily transcend class-based divisions and to generate an inclusive and voluntaristic association, which was both energising and self-limiting. In parallel, I analyse how politically-minded public university students revived historic aspirations for popular sovereignty, channelling the movement towards an antagonistic politics and testing the limits of student unity. Finally, tensions between electoral and anti-systemic politics underscored a vital and necessary confrontation between world views in a generational debate on Mexico’s future. Rescuing these tensions, analysing their underlying assumptions and placing them into dialogue with one another revives the transversal spirit of the movement, reveals hitherto under-examined instances of power and privilege, and tempers premature celebrations of its rupturing status.Mode of access: World wide web1 online resource (viii, 277 pages
Studies towards metabolically stable Fluorine-18 labelled peptides and their efficient syntheses
No full textTheoretical thesis."A thesis submitted in partial fulfillment of the requirements for the degree of Master of Research"--title page.Bibliography: pages 46-51.1. Introduction -- 2. Comparative stability of amide and sulfonamide model systems -- 3. Studies towards efficient direct labelling of peptides with Fluorine-18 -- 4. Materials and methods -- 5. Conclusions and future directions -- Appendices.Positron emission tomography (PET) is a powerful nuclear medicine imaging technique that has become invaluable for the in vivo diagnosis and staging of cancers and many other diseases. The overall aim of this project was to develop strategies for improving the metabolic stability and ease of synthesis of 18F radiolabelled peptide conjugates for use in PET. The first objective was to use model systems to determine if the substitution of an amide bond with a sulfonamide bond increases the metabolic stability of peptide conjugates. For this, N-benzoyl glycine and N-benzenesulfonyl glycine were incubated with the human carboxylesterase/amidase model enzyme pig liver esterase. Both compounds exhibited good stability, however, future work with other enzyme systems would be valuable. The second objective was to synthesise a series of bifunctional aromatic and heteroaromatic compounds that possess the good leaving group tetramethylammonium (TMA) and an activated 4-nitrophenyl ester to enable efficient fluorination and peptide conjugation. Unfortunately, the 4-nitrophenyl ester proved to be too active, making it difficult to form the TMA activated aromatic systems. As a result, a new method was developed based upon the synthesis of TMA methyl esters. Using this method, the synthesis of a TMA bearing methyl ester was successfully trialled.1 online resource (vi, 53 pages : illustrations
The expert in the aisles: exploring supermarket narratives in Coles and Woolworths magazines from 2009-2018 using machine learning techniques
No full textEmpirical thesis.Bibliography: pages 103-119.1. Introduction - 2. The digital promise -- 3. Defamiliarising diet and nutrition -- 4. Supermarket narratives -- 5. Digging deep into the text -- 6. Uncovering narratives : the expert in the aisles -- 7. Conclusion -- Appendices.In Australia, supermarkets dominate our food landscape, with over eighty-four percent of weekly food purchases occurring at the supermarket. The majority of this shopping occurs at either Coles or Woolworths. Given Coles and Woolworths’ dominance in food retailing, the messages they promote about food form important narratives that establish, reflect and reproduce broader cultural and social beliefs about taste.This thesis uses a combination of topic modelling, a type of machine learning, together with close reading to analyse the supermarket narratives found in the Coles and Woolworths magazines, Coles Magazine and Woolworths’ Fresh, published between 2009 and 2018. My analysis of these narratives demonstrates how supermarkets are positioning themselves as food and lifestyle authorities ready to instruct their customers on how to be good moral citizens through their consumption choices. Although the supermarket duopoly was subjected to intense external scrutiny and criticism from multiple sources during this period, my research finds this had little impact on their magazine narratives. Finally, my research highlights the benefits and analytical richness to be gained from combining topic modelling and close reading when performing content analysis on a large corpus of textMode of access: World wide web1 online resource (v, 119 pages) colour illustration
Syria in the mirror: the politics of belonging to Syria from Syrian diasporas in Armenia and Australia
No full textTheoretical thesis.Bibliography: pages 208-218.Preface -- Chapter 1. Introduction -- Chapter 2. Methodology -- Chapter 3. Approaches to Syrian identity and politicisation of identity -- Chapter 4. The new Syrian diaspora in Armenia and Australia -- Chapter 5. Arabism and minority in Syrian national identity -- Chapter 6. Sectarianisation in Syria and sectarian identity in diaspora -- Chapter 7. Secularisation and Islamisation in Syria versus secularity and religiosity in diaspora -- Chapter 8. Conclusion : the ambiguity of identity -- References -- Appendices.With the escalation of the conflict in Syria, since 2011, religious and ethnic groups have been increasingly politicised on the basis of identity. By studying Syrian immigrant communities in Armenia and Australia, this thesis explores Syrian diasporic transnationalism, testing how politicisation of identities in Syria permeate and condition what being Syrian means in exile. The focus is on the relationship between formulations of Syrian identity at the political level, before and after the outbreak of the conflict, and those of diasporic Syrian-ness.It is argued that Syria represents a case in which communal disunity is used to equate to political dissent, and where mobilisation around religious and/or ethnic identity is a result of social, political and economic disadvantage in periods of political crisis. The Syrian diasporas in the two countries chosen for the case studies, Armenia and Australia, give shape to a simplified reproduction of the politics of belonging at stake in the Syrian homeland.This thesis contributes new empirical knowledge about the political dimension of multi-layered Syrian identity. The analysis of Syrian diasporic political identity draws on interviews with Syrian-born representatives of Syrian immigrant associations, and 84 interview-based surveys with representatives, members, and independent Syrian respondents. What emerges from an integration of empirical results, theories and secondary sources is that with the sectarianisation of the conflict, the explicit use of ethno-religious identity in political debates has a social impact on diaspora. The nature of the influence is mixed: it has led both to divisions amongst SyrianTo frame the complexity and ambiguity of Syrian identity re-constructions, this thesis adopts a post-structuralist constructivist approach, which does not see group attachments and national cohesion as intrinsically dichotomous. On the contrary, this study demonstrates the need to understand under what circumstances the sub-loyalties can provide a solid basis for national cohesion. The results can help evaluate the effects of national crises of identity away from the state-centred perspective that has dominated Syrian studies.Mode of access: World wide web1 online resource (xii, 233 pages
Behind every great man: the position of women as expressed through tomb design in Middle Kingdom, Middle Egypt
No full textTheoretical thesis.Bibliography: pages 52-58.Chapter 1. Introduction -- Chapter 2. Artistic depictions -- Chapter 3. Textual references -- Chapter 4. Architecture -- Capter 5. Discussion and conclusion -- Bibliography -- Appendix.The purpose of this research is to analyse how women are incorporated into the decoration of Middle Kingdom tombs, and how this reflects their broader role in society. This has been done by focusing on the main elements of design within the tombs, at the neighbouring necropolises of Meir, Deir el-Bersha and Beni Hassan. Through analysis of the text, art and architectural features it is demonstrated that the representation of women in tombs was tied to that of the tomb owner, who were typically their husbands, fathers or sons. With few exceptions noble women have little independent representation within the broader decorative program; and women across the board only accounted for approximately 10% of human figures. Likewise women have a limited presence within the cultic focus of the tomb during the Middle Kingdom, namely on the false door or within the shrine. This is paralleled with developments in female titles during this period. Ultimately however, the design of the tomb reinforced the patriarchal social hierarchy. Although upper Egypt has some of the most extensive and well-preserved necropolises from the Middle Kingdom period, there has been limited research into the elite women of these sites; with only cursory investigations into their lives. More research is needed to fully understand how women were incorporated into tomb design.Mode of access: World wide web1 online resource (65 pages) black and white illustration
Cognitive and behavioural plasticity in the intertidal Cocos Frillgoby (Bathygobius cocosensis)
No full textEmpirical thesis.Bibliography: pages 157-181.Chapter 1. General introduction -- Chapter 2. Trophic niche plasticity : investigating seasonal and ontogenetic shifts in three intertidal gobies -- Chapter 3. Sexually dimorphic spatial learning is seasonally driven in the intertidal Cocos Frillgoby (Bathygobius cocosensis) -- Chapter 4. Environmental enrichment influences spatial learning ability in captive-reared Bathygobius cocosensis -- Chapter 5. Evidence of behavioural syndromes in wild but not captive-reared Cocos Frillgoby (Bathygobius cocosensis) -- Chapter 6. No evidence of population-level laterality in wild and captive-reared gobies (Bathygobius cocosensis) -- General discussion -- Appendices -- References.The age-old dichotomy of nature versus nurture continues to spark debate in the context of plastic behaviour, and not just when it comes to humans. Every year there is further evidence illustrating how individual experience shapes personality, behaviour and cognitive ability, all of which are fundamental aspects of an individual’s phenotype. Ultimately, experience is intricately linked to an individual’s environment, and numerous studies have focused on population differences in behaviour. Key explanatory variables include variation in predation, competition and habitat stability/physical complexity. Despite their evolutionary history being embedded in ancient lineages, and the associated popularist idea that they are ‘simple and primitive,’ fishes demonstrate highly flexible behaviour. Moreover, they have become one of the leading vertebrate taxa in behavioural plasticity studies using comparative approaches, not least because of the wide range of aquatic habitats 20they occupy.In marine coastal environments, the intertidal zone is a highly dynamic habitat and home to one of the largest and most successful groups of fishes (>2000 spp), the family Gobiidae. This family is well-adapted to the intertidal zone morphologically and behaviourally, both aspects of which differ widely in species occupying different micro-habitats. Their sheer diversity offers exciting opportunities for comparative studies which attempt to untangle the relative influence of genes versus experience in shaping behaviour.Despite the diversity of intertidal gobies, niche overlap is common and competition for resources plays a vital role in behaviours such as foraging, suggesting that behavioural plasticity would be beneficial when securing resources. Furthermore, food resources in the intertidal zone vary on temporal and spatial scales, so that individuals with flexible behaviour can adjust to these changes and thus reap the fitness benefits. Chapter 2 of this thesis focuses on the niche overlap of two sympatric goby species, one rockpool specialist and one sand specialist, and how this overlap changes seasonally and ontogenetically. In addition, the trophic niche of a third allopatric species was investigated, to determine how diet changes seasonally and ontogenetically in the absence of interspecific competition. In the sympatric species, we found a seasonal switch in diet complexity, where the sand species consumed a variety of prey taxa in winter but not summer, and vice versa for the rockpool specialist. In contrast, the allopatric species showed similar diet complexity across seasons but shifted toward a specialised diet later in ontogeny.Seasonal change has been tied to variation in cognition, whereby changes in cognitive function are linked to reproductive demands and can differ dramatically between sexes, depending on life-history strategies. Although this has been demonstrated in several mammalian species, few have investigated sexually dimorphic cognitive ability in fishes, and none in the context of reproductive strategy. Rockpool gobies demonstrate exceptional cognitive function by way of spatial learning ability so Chapter 3 focused on the male nest-guarding mating system in the intertidal goby Bathygobius cocosensis and how it influenced male and female cognitive abilities in a spatial learning task in each season. Males and females performed similarly in all seasons except spring, which marks the breeding season in this species. Males showed a substantial decrease in cognitive ability while females did not. I suggest that the decreased cognitive ability observed in males during the breeding season is linked to their reproductive strategy; males are site-attached whilst they guard their nests and forgo foraging excursions. This study highlights the importance of cognitive plasticity and how individuals manage the trade-off between costs and benefits associated with enhanced cognition over relatively short temporal scales.The ecological cognition hypothesis suggests that an individual’s brain and behaviour are greatly influenced by environmental characteristics such as stability and predictability. However, whether the plasticity of these aspects is finite or otherwise constrained by inherited genetic mechanisms shaped by evolutionary pressures over multiple generations, remains unexplored in gobies. To that end, Chapters 4, 5 and 6 examined environmental drivers of spatial learning ability, anti-predator behaviour and laterality in gobies, using a wild-captive comparative framework. Previous studies have shown that rockpool gobies possess superior spatial learning abilities compared to sand specialist gobies, associated with the selective environmental pressures of living in a structurally complex habitat. However, whether this ability is fixed and innate, or flexible and shaped by experience, remains unknown. In Chapter 4, I reared juvenile gobies in 4 different habitats that varied in the degree of physical complexity and trained them to solve a simple spatial learning task. I found that gobies reared in structurally complex habitats solved the task faster than those reared in the simpler regimes, suggesting that, although spatial learning ability may have an innate component, life experience shaped by environmental heterogeneity continues to alter learning ability in later ontogenetic stages.In addition to controlled manipulation of the physical environment, captivity also allows researchers to regulate the social environment, such as predation pressure. Wild gobies were captured as adults with experience in assessing visual and olfactory cues to ascertain predation risk and altering their behaviour accordingly, while captive gobies were captured as juveniles and reared in the absence of predation risk. In Chapter 5, wild and captive-reared gobies were exposed to a series of cues from a sympatric predatory crab species and their anti-predator behaviours observed. In addition, I paid close attention to correlations between behaviours which may indicate population-level behavioural syndromes which, in other taxa, are most often manifested in high-predation contexts. Captive-reared gobies showed little differences in behaviour, regardless of cue treatment, although larger individuals generally spent less time moving in the presence of the predator. In the wild population, large individuals spent less time moving than smaller individuals, and gobies exposed to olfactory cues were less active than those in visual and control treatments. The relationship between activity and size emphasises the importance of body size in risk-related behaviour and the influence of captive- rearing on animal behaviour more broadly. As predicted, behavioural syndromes were only observed in wild fish when exposed to olfactory cues (olfactory cues alone or in combination with visual cues) emanating from predators, which aligns well with the existing literature.Previous studies have shown that behavioural differences in gobies from contrasting environments are mirrored in brain morphology, exemplified by larger telencephala in rockpool specialists compared to sand specialists. The question remains whether laterality, the preferred use of one brain hemisphere over another when assessing information, is similarly influenced by habitat complexity. Existing literature suggests that laterality is influenced by both habitat complexity and predation pressure. Chapter 6 focused on whether gobies exhibit population-level laterality and if differences exist between captive and wild populations. Trials were conducted using a mirror test, where the body position of gobies was observed, and eye use preference recorded. I found no evidence of population-level laterality in either group, although there was a tendency toward stronger lateralisation with increasing size, indicating laterality remains plastic throughout ontogeny. Moreover, this data supports the existing literature which suggests that population-level laterality occurs most often in highly social species.In summary, the research outlined in this thesis emphasises the plasticity of behaviour in a species that occupies a complex and dynamic habitat, and how the extent of this plasticity can be altered with controlled manipulation of environment in early ontogeny. It also highlights the strengths of a comparative framework, particularly when captive experience is improved with environmental enrichment to encourage natural behaviours in fishes.Mode of access: World wide web1 online resource (181 pages) graphs, table
Characterisation and detections of third-party content loading in the web
No full textEmpirical thesis.Bibliography: pages 47-54.1. Introduction -- 2. Literature review -- 3. Technical background -- 4. Experimental evaluation -- 5. Conclusion -- References.The Web has evolved into a tangled mass of interconnected services within the last two decades,where websites import resources i.e. data or contents from third-party domains. These domains serve several purposes including analytics, tracking and advertisement. Websites trust their third parties for resources in the process of loading contents or data to their web pages. The dependency of resources sometimes extend further from third-party domains to other domains thus fabricating a chain of dependency. In the resource dependency chain, the first party websites are indeed trusting resources obtained by their direct third-parties through requests to other domains. The chain of dependency cannot be rigidly controlled by the first-party websites as they have very scarce or no information of where the loaded content have originated from. Since this is the case, the websites even end up trusting compromised websites for contents unknowingly and become prone to multifarious attacks. We characterize the implicit trust in the chain of dependency for Alexa's top 30k websites and estimate the level of risks that first-party websites may be venturing while loading resources from thirty-party domains. We found that 10.55% of the resources of top-1000 Alexa websites are obtained implicitly and that they constitute 4.1% of malicious resources in the overall count of external resources.Mode of access: World wide web1 online resource (xiv, 54 pages) graphs, table
The visual system of the blind shark (Brachaelurus waddi)
No full textTheoretical thesis.Bibliography: pages 33-37.1. Introduction -- 2. Methods -- 3. Results -- 4. Discussion -- References -- Appendix.Sharks have evolved over a period of approximately 400 million years. This extensive time frame has resulted in a divergence of shark species that occupy a wide range of environments and exhibit considerable diversity in morphology and behavior. It is likely that this diversity is reflected in the anatomy and physiology of shark visual systems. However, only a very small proportion of extant shark species has been studied in detail and much remains to be discovered about interspecific variation in their visual system. Furthermore, there have been no studies to date that have undertaken a comprehensive assessment of the visual abilities of a single shark species. Blind sharks (Brachaelurus waddi) are a benthic species found in abundance along Australia’s coast and adapt well in captivity, which makes them amenable to an in-depth assessment of their visual system. In this study, the anatomy and physiology of the blind shark’s eye was investigated and the results interpreted within the context of their environment and behavior. Electrophysiological techniques were used to measure the temporal resolution and contrast sensitivity of the eye. The spectral absorption properties of the photoreceptor visual pigments that subserve vision were measured in situ using single cell microspectrophotometry. Spatial resolving power was assessed by measuring the topographic distribution of ganglion cells in wholemounted retinas. When presented with a sinusoidally modulated light stimulus, blind sharks have a maximum critical flicker fusion rate of 22 Hz and a contrast sensitivity threshold of 177.6 (0.56%) at the brightest light intensity. Rods were the only type of photoreceptor identified in the retina. The rods contained a medium-wavelength (‘green’) sensitive visual pigment with a mean max at 501 nm. The topographic distribution of ganglion cells in B. waddi showed a weakly defined, elongated horizontal band or visual streak of higher density in the central-dorsal region of the retina. Based on the mean peak density of ganglion cells in the retina, the estimated spatial resolving power of the eye was 2.36 cycles per degree (cpd).Mode of access: World wide web1 online resource (39 pages) colour illustration