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On a global scale there are few greater threats to human health than the rapid rise of antibiotic resistance. It is therefore of crucial importance to discover and develop new antibiotics for clinical use. This thesis describes investigations into synthetic strategies to antibiotic natural products and novel derivatives.

Botulinum neurotoxins (BoNTs) are the deadliest proteins known and cause flacid paralysis through inhibition of acetylcholine release from motor neurons. Each BoNT consists of three domains: the binding domain, the translocation domain and the catalytic light chain. The binding domain is responsible for the targetting of neuronal cell membranes and is able to form a dual-receptor complex with cell-surface receptors. The BoNT is taken into the cell through endocytosis where the translocation domain acts to release the catalytic light chain into the cell cytosol. The light chain is then free to cleave one of the SNARE (soluble N-ethylmaleimide-sensitive-fusion-protein attachment protein receptor) proteins, inhibiting exocytosis and thus neurotransmitter release. BoNTs are categorised into serotypes (BoNT/A to /G) and subtypes (e.g. BoNT/A1) based on amino acid variations. BoNTs have many therapeutic uses including as a treatment for cervical dytonia, strabismus, and overactive bladder and the most common commercially available product consists of BoNT/A1. Subtle amino acid variations between BoNT subtypes may have a dramatic impact on the properties of the protein, some of which may be useful for the production of engineered BoNTs in the future. In this thesis, the crystal structures of the binding domains from BoNT/A1 to /A6 were determined to high resolution and their binding to the protein-receptor SV2 was investigated. The structures of full-length BoNTs in solution were also investigated to confirm whether multiple domain-organisations exist across BoNT serotypes. There are over 150 different BoNTs known and this work also includes a new open-access tool for identifying and retrieving information about specific BoNTs in a fast and easy way.

Primary Sjogren's Syndrome (PSS) patients will suffer a variable degree of damage to their salivary glands, caused by lesions of immune infiltrates into the tissue surrounding duct structures. Some patients present with extensive lesions that destroy any residual secretory acinar tissue, leading to hyposalivation. This damage, and reduced salivation, can lead to deleterious effects on the oral health, such as increased risk of caries and periodontitis, and will impact the general quality of life of the patients and can increase their risk of developing other, more serious conditions. Previously, there has been limited knowledge and characterisation of how different cell populations are impacted by PSS. Therefore, this project developed clear characterisation of labial salivary gland tissue from patients presenting with PSS compared to non-PSS patient samples. It was shown that regions that were not directly associated to lesions present with the same phenotypical profile as observed in non-PSS patients, indicating a very limited focal impact of the disorder. These regions stained positively for E-cadherin and Vimentin in patterns that were comparable to non-PSS patient samples. Simultaneously, the directly affected lesion regions presented with complete absence of any healthy salivary gland cell markers. Peri-lesion tissue presented with subtle changes to marker expression; here we could identify changes to mesenchymal cell markers such as PDGFRb and CD29 between the PSS and non-PSS tissue. The established immunofluorescent markers could further be used in later experimentations to identify each cell population, particularly when developing cell cultures and organoid models. 23 In order to investigate the impact of PSS on the ability of cells to proliferate and perform a rudimentary regenerative function, the group developed cell cultures that were representative of epithelial and mesenchymal cell types and recombined them to form organoid models. These models were first developed using mouse derived cell cultures before being adapted for use with human derived cells. Using these organoid models, it was possible to demonstrate that mesenchymal cells isolated from PSS positive patients had a reduced ability to direct the regenerative capacity of the epithelial spheroid structures, resulting in smaller, less complex, and less functionally advanced organoids than those developed using non-PSS derived cells. During this study, standard techniques were used such as quantitative real-time PCR of relative mRNA expression levels, immunofluorescent staining, and laser capture microdissection (LCM), whilst a novel organoid culture technique was optimised. Since these models have been established, it is thought that they could be adapted to investigate other disease or environmental impact on the salivary gland tissue, with some preliminary studies attempting to investigate the impact of x-ray irradiation exposure on the tissue. Furthermore, the technique could possibly be extrapolated to other tissue types to aid the understanding of the effect of other autoimmune conditions on their target tissues. In conclusion, this project shows mesenchymal cells appear to play an important and necessary role within tissue regeneration models. There is a significant change to cell fate determination pathways in PSS positive patient biopsies, and these mechanistic changes now need to be studied further within the constraints of the organoid model that has been developed.

The research conducted for this thesis is an exploratory study of migrant workers' experiences in UK food supply chains. This thesis provides an original contribution to criminology by discussing how some food supply chain dynamics result in various exploitative and harmful labour practices against migrant workers. Data consisted of semi-structured interviews conducted with migrant workers in the UK, as well as individual and group interviews with food supply chain stakeholders, including representatives from industry, regulation, and labour movements. This research conceptualises labour exploitation as a continuum, with severe practices including modern slavery on one extreme and 'decent work' on the other. There are a range of practices in-between these two extremes that risk being overlooked, whereby 'routine', banal exploitation is embedded and normalised within legitimate supply chain processes. The argument developed in this thesis is that a stronger emphasis is needed on the harmful consequences of routine, mundane, everyday labour exploitation in order to understand how they can result from legitimate supply chain dynamics. The key contributions of this thesis can be summarised under four themes: developing a more rigorous analysis of 'routine' labour exploitation and harm against migrant workers; understanding how legitimate food supply chain dynamics can facilitate exploitation and harm; explaining how the regulatory framework may unwittingly result in further exploitation and harm to migrant workers; and recognising the complexity of the relationship between migration and labour exploitation. The thesis findings contribute to predominant discussions of labour exploitation that typically focus on severe exploitation such as modern slavery and emphasise rogue individuals or criminal networks as the main perpetrators. The research findings demonstrate that a significant amount of routine labour exploitation and harm remains 'under the radar' in the context of legitimate supply chain practices. Police action and supply chain regulation typically focuses on the most severe labour exploitation, which results in routine exploitation being largely unaddressed. Therefore, labour exploitation has implications for the nature, organisation, and control of harms facilitated by businesses and supply chains. It is important for criminology and society to not disregard routine labour exploitation, as these practices can result in numerous harmful consequences for workers. Since the public profile of labour exploitation continues to grow, a stronger focus is needed on the routine and banal aspects, not just the most severe practices.

Magnetoencephalography (MEG) is a neuroimaging method for mapping brain activity based on magnetic field recordings. The inverse problem associated with MEG is severely ill-posed and is complicated by the presence of high collinearity in the forward (leadfield) matrix. This means that accurate source localisation can be challenging. The most commonly used methods for solving the MEG problem do not employ sparsity to help reduce the dimensions of the problem. In this thesis we review a number of the sparse regression methods that are widely used in statistics, as well as some more recent methods, and assess their performance in the context of MEG data. Due to the complexity of the forward model in MEG, the presence of measurement-error in the leadfield matrix can create issues in the spatial resolution of the data. Therefore we investigate the impact of measurement-error on sparse regression methods as well as how we can correct for it. We adapt the conditional score and simulation extrapolation (SIMEX) methods for use with sparse regression methods and build on an existing corrected lasso method to cover the elastic net penalty. These methods are demonstrated using a number of simulations for different types of measurement-error and are also tested with real MEG data. The measurement-error methods perform well in simulations, including high dimensional examples, where they are able to correct for attenuation bias in the true covariates. However the extent of their correction is much more restricted in the more complex MEG data where covariates are highly correlated and there is uncertainty over the distribution of the error.

This thesis investigates the problem of contemporary historiography and regime representation in Flavian Rome through a close study of a text not usually read for such purposes but which has obvious promise for a study of this theme, the Jewish War of Flavius Josephus. Having surveyed the evolution of our conception of Josephus' relationship to Flavian power, taken a broad account of issues of political expression and regime representation in Flavian Rome outside Josephus and examined questions relating to the structure and date of the work, I will provide a series of thematically-focused readings of the three senior members of the Flavian family, Vespasian, Titus and Domitian, as represented by their contemporary and client Josephus. Key topics to be explored include the level of independence of Josephus' vision, his work's relationship to how the regime is depicted in other contemporary sources, how Josephus makes the Flavians serve his own agenda (which is distinct from the heavy focus of most previous scholarship on how Josephus served their agenda), and the viability and usefulness of certain types of reading practices relating to figured critique which have recently become influential in Josephan scholarship. The thesis offers a new approach to Josephus' relationship to the Flavian Dynasty and sheds new light on contemporary historiography and political expression in the Early Principate.

The reversible action of tungsten or molybdenum-containing formate dehydrogenase (FDH) enzymes in reducing CO2 to formate has been proposed for storing renewably produced electricity with concomitant CO2 sequestration. Previous attempts have highlighted the unfeasibility of using purified enzyme systems for biotechnological purposes. In response the possibility of using the exoelectrogenic bacteria Shewanella oneidensis in association with a cathode to drive intracellular CO2 reduction is proposed. Since the native FDH enzymes of S.oneidensis have not been previously studied, this work concerns their characterisation and directionality to inform both on native physiology and possible future biotechnological applications. This thesis demonstrates that the native FDH enzymes of S.oneidensis are capable of CO2 reductase activity. Both forward (Km 39 μM) and reverse (Km 1.43 mM) directions of FDH catalysis in whole cell cultures are maximal when cultured in the presence of W. When grown under such conditions, two FDH isoforms (Fdh1αβγ and Fdh2αβγ) contribute to these activities, with protein purification confirming Fdh2αβγ as a tungstoenzyme. CO2 reductase activity in S.oneidensis cultures could be driven by a cathode in simple three electrode electrochemical experiments without exogenous mediators with high coloumbic efficiency, representing an interesting paradigm for future inexpensive microbial electrosynthetic study.

Globally, higher education institutions (HEIs) can help facilitate the transition to a low-carbon society through their role as educators, researchers and community leaders. Focusing on their role as educators, one of the central concepts of education for sustainable development is global citizenship, where for UK HEIs the recruitment of international students and study abroad schemes have been a fundamental way of encouraging home students to develop global perspectives. However, this approach conflicts with the sector's low-carbon agenda due to the significant emissions from air travel (hereafter 'the Conflict'). To evaluate the scale of student air travel emissions, and to explore students and HEIs awareness of, and willingness to mitigate and/or compensate for these emissions, this study adopted a convergent and integrated parallel strand mixed methods design. This comprised of a cross-sectional survey of 663 international and study abroad students and document analysis and in-depth interviews under the umbrella of eight HEI case studies. An analysis of UK HE sector statistics, in combination with flight frequencies determined from the student survey, found that student air travel emissions were equivalent to 68% of estates emissions, or 119% when visiting friends and relatives were taken into account. Furthermore, scenario analysis suggested that by 2020/21, increases in these emissions are likely to exceed the reductions achieved in estates emissions unless HEIs reinvigorate efforts to achieve their ambitious reduction targets, and/or there is close to zero annual growth in inbound and outbound student numbers. The findings from the eight case studies revealed that the sector is poorly equipped to respond to the Conflict. This relates to an ongoing focus on, and difficulties achieving, estates emission reductions, varied engagement with indirect (supply chain) emissions, and an unwillingness at the institutional level from the majority of HEIs to engage with the Conflict. To have credibility and be in a position to respond strategically to the Conflict, HEIs should include student air travel emissions in a comprehensive carbon footprint. Moreover, a robust carbon management strategy for the sector should include offsetting due to the limited potential to avoid or reduce these emissions through reduction in air travel consumption. This is evidenced by both responses to the student survey and the importance placed on student mobility by the HEIs. Clearly, there are challenges for organisations who face conflicting business priorities in responding to the carbon management agenda. Organisations need to account for and engage with indirect emission sources such as employee commuting and business travel, and the emissions associated with products (goods and services). The reluctance and inability to engage with challenges that require a trade-off, or compromise between socio-economic benefits and environmental costs has implications for the achievability of a global reduction in emissions.

This study employed adaptation paradigms to explore visual motion processing during smooth pursuit eye movement. Two classes of model, classical models and reference signal models, employ estimates of retinal motion and pursuit to estimate head-centred world motion. The pursuit estimate in classical models is purely extra-retinal. In reference signal models the pursuit estimate is additionally modulated by retinal feedback. Chapters 2 and 3 investigated the motion aftereffect (MAE) following adaptation to simultaneous retinal motion and smooth pursuit. In chapter 2 adaptations to either horizontal retinal motion or vertical smooth pursuit respectively resulted in retinal or extra-retinal MAE. Simultaneous orthogonal adaptation to both motions resulted in a unidirectional MAE that bisected the individual MAE directions. Adaptation to a head-centred motion signal (perceived direction) was not supported by the recorded directions for adapting motion and resulting MAE. An explanation employing separate lower level adaptations was favoured. Chapters 3 and 4 examined motion perception following collinear motion adaptation. Additionally, the retinotopic nature of retinal motion adaptation was exploited to limit the effects of retinal sensor adaptation during the test phase. The two classes of model then make differing predictions: Reference signal models predict a pursuit estimate that is modulated by retinal motion, whilst classical models do not. In chapter 3 varying the background motion during adaptation did alter the physical eye movement. However, the properties of the resulting MAE were not modulated by retinal feedback and a classical model was supported. Chapter 4 used a moving test to quantify the perceived stability of a background during smooth pursuit using a two alternative forced choice paradigm and staircase procedure. Either a phantom velocity aftereffect or a modified reference signal model was suggested as modulating the Filehne illusion in Experiment 6. Two control experiments failed to find evidence for phantom adaptation. Experiment 9 demonstrated a potential retinotopic location bias for background motion when applying a reference signal model, background motion above the test area did not alter perceived stability judgments.

If we were to ask the question, "why does organism X develop/behave as it does?" or, "why does organism X give rise (through e.g. sexual reproduction) to an organism that is similar to itself?" we have two broad types of explanation: the localised and the distributed. These, and other questions addressed in developmental and evolutionary biology, I characterise as problems of biology. Localised causal explanations (LCEs) focus on the identification of an entity (localised in space) or event (localised in time) responsible for the phenomenon to be explained. Distributed causal explanations (DCEs) have tended to focus on the identification of (often global) properties or features (distributed in space) or processes (distributed in time) responsible for the phenomenon to be explained.

Converging evidence suggests that it is not until the age of approximately 4 years that children can mentally time-travel back in time to re-experience episodes from their life (‘episodic memory’). This research was motivated by two questions: (1) how does episodic-like memory emerge out of event memory? And (2) to what extend does episodic-like memory share some of the psychological characteristics of episodic memory (e.g. the putative dependence on grasping the representing relationship between knowledge and experience, as demonstrated by tests of seeing-leads-to-knowing)? Three tasks were conducted to address these issues. The first, the ‘two-object what & where’ task employed an object-placement/witnessed pilfer design, and found that shortly after the second birthday children become able to integrate ‘what’ information (with respect to objects) in day-long location memory. In the ‘Tim and Tom’ task, deferred imitation of a two-step action sequence was used to demonstrate the presence of day-long event memory in children upwards of 36-months-of-age. Finally, the ‘what, where, when’ task tested for the presence of episodic-like memory in 3- to 4-year-olds, and established that children found conditions which require them to remember how long ago an event had happened were significantly harder than conditions without this requirement. The abilities tested by the ‘what, where, when’ task were not found to recruit theory-of-mind or seeing-leads-to-knowing abilities. Given this, the ‘what, where, when’ task can be interpreted as supporting the distinction drawn between episodic and episodic-like memory.

Adsorbed and incorporated ruthenium on Pt(110) has been probed using the techniques of LEISS, LEED and XPS. Well characterised alloy surfaces have been prepared by annealing in the temperature range 400-1100K and the temperature programmed desorption of CO investigated. Second layer ruthenium is shown to have a major effect on the adsorption characteristics of CO. The catalytic activity of these surfaces towards the electro-oxidation of CO has been determined using cyclic voltammetry. The reversible hydrogen adsorption peaks are perturbed by subsurface ruthenium, however, promotion of the electro-oxidation of CO, as evidenced by a downwards potential shift, occurs solely due to ruthenium incorporated into the top atomic layer. The adsorption of ruthenium on Pt(111) has been investigated by LEISS, XPS and LEED. At room temperature clusters of ruthenium are obtained. On annealing competition occurs between the processes of spreading of these clusters and incorporation of ruthenium into the Pt(111) surface. Two Clavilier bead crystals have been prepared of the Pt(111) and Pt(533) surfaces. Promotion of the electro-oxidation of CO by ruthenium spontaneously deposited onto these surfaces from a RuCl₃ solution, before and after reduction of the surface ruthenium species, has been demonstrated. A particularly sharp oxidation peak at 0.53 V is observed on the Pt(533) - Ru system after exposure to hydrogen, attributed to the formation of an ideal "alloy" ensemble at the step.

Nudibranchia is the major Order of the gastropod Sub-class Opisthobranchia. Nudibranchs demonstrate a considerable evolutionary departure from the typical shelled gastropod and have achieved wide morphological and ecological diversity. Most species are recorded from nearshore rocky habitats where they are primary macrobenthic predators; most species are stenophagous limited to a single, or a few, prey species. Previous investigations had shown that most nudibranch species have evolved to an annual semelparous life history strategy and adopt a planktotrophic larval development strategy which would appear to be the ancestral conditions. Reviews of published data had drawn attention to some species which demonstrated an evolutionary departure from these ancestral modes and had evolved extended life history strategies combined with more advanced larval development strategies. Archidoris pseudoargus and Cadlina laevis are sponge-grazing dorid nudibranchs, and Tritonia hombergi, which feeds on an alyconarean soft coral, appeared to have extended life cycles. The aim of the present study was to investigate the life history and larval development strategies of these species and, via a study their physiological ecology, attempt to determine the selective forces which may have driven any evolutionary departure away from the ancestral condition. Archidoris pseudoargus was found to have a biennial semelparous life history strategy and a planktotrophic larval development strategy; the planktotrophic lai'vae were found to have some characteristics of the more advanced lecithotrophic laeval form. Cadlina laevis was found to have a perennial iteropalous life history strategy and a direct mode of larval development; this was the first observation of perennial iteroparity in the Order Nudibranchia. Archidoris pseudoargus and Cadlina laevis had markedly seasonal growth patterns with a high growth rate in spring and early summer, followed by a period of reduced growth, or even degrowth in late summer and over the winter. An allometric relationship was determined between body size and feeding rate for A. pseudoargus; the exponent was less than unity. For both species, a significant allometric relationship was determined between body size and respiration rate with an exponent less than unity indicating an increase in metabolic efficiency with body size. Both species displayed an acclimatization of respiration rate with increasing temperature; the acclimatization was more pronounced in C. laevis. Fecundity of both species was shown to have a significant allometric relationship body size with an exponent less than unity. Insufficient numbers of T. hombergi were collected and kept alive in the laboratory to undertake any experiments to generate meaningful data to answer these principal questions for this species. Results of the present study together with data published from previous investigations have been interpreted to suggest that the extension of the life cycle is a consequence of seasonal variations in prey quality and quantity. Rather than being an exception to the rule, it is suggested that extended life cycles could be the ancestral condition and the more common annual/sub annual life cycles would be a more adapted condition. These conclusions are based on the results obtained from laboratory investigations which are discussed in their application to the field situation.

This Thesis aims to increase the understanding of the way in which herbicides inhibit plant photosynthesis by interference at the site of photosystem II. Two structurally dissimilar series of compounds, provided by Schering Agrochemicals (Saffron Walden, U.K.), one rigid, one flexible, both series showing varying herbicidal activity, were submitted to X-ray crystallography, NMR spectroscopy and molecular modelling studies. As a result of these investigations, an explanation is given for the observed trend in activity of both series of compounds. A template for the herbicide binding site is also presented. The most active molecules in the two series of' compounds were compared using molecular modelling. A model is presented which suggests that both molecules may interact with the same binding site at the photosystem II reaction centre.

In the filamentous fungus Aspergillus nidulans, the NIMA kinase is required along with CDK1/cyclinB for mitotic entry. The essential function of NIMA in A. nidulans and the growing recognition of its importance in other eukaryotes, means that the study of NIMA function should reveal unique insights into cell cycle regulation amongst a broad range of organisms. I describe here the characterization of TINC and TIND, two NIMA interacting proteins identified in a yeast Two-hybrid screen, and describe the potential novel roles they may play in mitotic regulation. TINC and a related protein in A. nidulans, An-HETC, are highly similar to proteins conserved in filamentous fungi. Strains which lack both tinC and An-hetC are viable, but do display osmotic and cold sensitivity. Characterization of TINC suggests that it is involved in mitotic regulation. First, TINC is present in the nucleus during mitosis. Second, TINC interacts with NIMA in a phosphorylation state dependant manner. Third, truncated forms of TINC (ΔN-TINC) produce cell cycle defects characterized by a defect in nuclear membrane fission in which cells are able to separate DNA but unable to cleave the nuclear envelope. Significantly, ΔN-TINC localizes to membranous bodies which associate with nuclei. Finally, expression of ΔN-TINC promotes premature loss of NIMA from mitotic samples. The second NIMA interacting protein, TIND, is conserved from bacteria through to humans. TIND is predominantly mitochondrial throughout the cell cycle, but work in other organisms suggests that alternate forms of TIND may exist outside the mitochondria. Expression of a form of TIND which lacks the mitochondrial targeting peptide (ΔN-TIND) produces nuclear division and nuclear membrane fission defects similar to those seen for ΔN-TINC. Additionally, ΔN-TIND also produces defective mitotic spindles, which appear monopolar, an effect not seen for ΔN-TINC. The facts that TINC and TIND were isolated as NIMA interacting proteins, TINC interacts with NIMA in A. nidulans, and expression of ΔN-TINC or ΔN-TIND produces specific defects in nuclear membrane fission suggest roles for these proteins in mitotic regulation. Additionally, the finding that NIMA is destabilized in cells displaying mitotic defects suggests a role for NIMA in regulating nuclear membrane fission.