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In high-dimensional regression problems, a key aim is to identify a sparse model that fits the data well. This may be used to form accurate predictions or to gain subject-matter understanding. When strong dependence is present among covariates, it is common for many models to fit the data equally well. Whilst it is sufficient to report a single model for prediction, when the goal is to gain subject-matter understanding, Cox & Battey (2017) argue that a confidence set of models - a set consisting of all models of appropriate fit - should be reported and propose a method to achieve this aim. This thesis provides a theoretical elucidation of this approach, and based on the results, explores further ideas in high-dimensional data analysis.

As a group, birds are facing continued declines in conservation status. As such, ex situ management is becoming a more widely used and important tool in conservation programmes. However, adaptation to captivity and behavioural change during ex situ breeding programmes may reduce the success of these interventions. Changes in mating traits, such as vocal behaviour, may be particularly important. In this thesis, I examine the potential for vocal evolution during ex situ conservation to determine how it could impact conservation efforts, focusing on the Java sparrow (Lonchura oryzivora), an endangered estrildid finch. Firstly, I examine the existing literature to determine how vocal behaviour could impact on conservation actions and how potential problems could be mitigated (Chapter 2). Vocal learning and the formation of population dialects have particular significance in conservation programmes due to their effects on important behaviours, such as mate choice. Java sparrows learn a number of components of their song, including song complexity and note acoustic structure (Chapter 3). Birds also learned many temporal features of song, such as tempo, the inheritance of which has been less frequently studied (Chapter 4). Given the importance of vocal learning in song development, there is a high potential for vocal change and population divergence during ex situ breeding in this species. Such differences are important for mate preference; Java sparrow females preferred familiar, over unfamiliar, songs (Chapter 5). Preference for familiar songs may result in assortative mating between individuals of different population origin during conservation efforts, reducing the effectiveness of conservation programmes. As well as behavioural changes, other phenotypic changes may occur in captivity. Captive Java sparrows were both larger and had greater sexual size dimorphism than those of wild origin (Chapter 6). Morphological changes during captive breeding may reduce the performance of captive-bred individuals in wild environments, as well as affecting other, correlated traits, such as vocal behaviour. Vocal behaviour may also be affected by altered sound environments experienced by birds during ex situ breeding programmes. Human presence has a significant effect on the zoo soundscape; reduction in human presence during the COVID-19 lockdown was associated with a number of changes in the sound environment (Chapter 7). Overall, there is significant potential for vocal evolution during the captive breeding of Java sparrows, mediated by cultural processes resulting from social learning of vocalizations, environmental differences, and other, correlated changes. Changes in vocal behaviour in the Java sparrow could affect conservation programmes due to preferences for familiar vocalizations in this species by contributing to assortative mating. The findings from this species suggest that vocal behaviour can have an important role in the success of conservation efforts and requires further investigation in this and other species.

Climate change is one of the key issues of our time, causing rapid changes to habitats worldwide and exerting novel pressures on natural populations. Central to understanding species responses to climate change is the process of thermal adaptation, whereby populations adapt to increased or changing temperatures. However, we do not understand how important thermal adaptation is in nature, nor the phenotypes that underpin it. Understanding thermal adaptation in insect species is of particular interest, as they provide many ecosystem services (e.g. pollination, pest control and recycling of organic matter), and are particularly vulnerable to temperature changes due to their inability to thermoregulate. Additionally, several pervasive pest species are insects, so understanding how they will respond to climate change will have major impacts on food security. Here, I investigate thermal adaptation using Tribolium castaneum, which is the model beetle and a globally important pest of stored products. I use experimentally evolved populations exposed to control temperature (30°C) or stressful high temperature (38°C) for over 50 generations, to investigate how thermal adaptation occurs and the effects of population demographics and life history on this. I found that high temperature lines had lower overall reproductive output compared to control lines, even when reproduction occurred at high temperatures. I then experimentally increased population size and induced migration into the high temperature lines for 10 generations, to increase levels of genetic diversity, but found that this did not result in increased reproductive output or survival. However, when the experimental populations underwent development at high temperature, I found markedly reduced reproductive output in the control lines, but not the high temperature lines. Development at high temperature affected the fecundity of adult females and the fertility of adult males, and I identified morphological differences in the ovaries and testes of beetles following development at 38°C or 30°C. Furthermore, this adaptation appears to occur rapidly, with observable signals of change in reproductive morphology and increased reproductive output within just five generations. This thesis highlights that there is potential for rapid adaptation in insects, which suggests that there is a chance they may cope with climate change. However, it also demonstrated the complexity of thermal adaptation, and more in-depth understanding is required to accurately predict the outcomes of changes in temperature.

To meet the nutritional requirements of a growing population, world agricultural output must increase by 70-100% by 2050. However, worldwide wheat yields are close to reaching a 'glass ceiling'. In order to meet the challenges of a rapidly growing population, scarcity of resources and a trend toward high-protein diets, traditional agriculture has looked towards molecular biology for insight and innovation for the future. Studying the mechanisms underlying DNA damage and repair is crucially important to facilitating generation of novel variation and developing breeding techniques. The Mismatch Repair (MMR) system is a highly-conserved series of pathways responsible for maintaining genomic integrity in prokaryotes and eukaryotes. The constituent proteins repair DNA mismatches and prevent meiotic recombination between homoeologous sequences. Work in Arabidopsis, tobacco and tomato has shown that plants with an impaired MMR system accumulate point mutations and undergo increased homoeologous recombination, which may be useful in breeding programs. Two key MMR genes are explored: MutS Homologue 2 (MSH2) acts as a heterodimer with MSH3, MSH6 or MSH7 to detect point mutations, insertions and deletions. Post Meiotic Segregation increased 2 (PMS2) is a homologue of the MutL gene, which co-ordinates repair of mismatches. The two genes were cloned and sequenced from elite cultivar Cadenza, and the sequences subsequently compared to next generation sequencing data from Chinese Spring. Three homoeologous copies of each gene were identified in the genome of wheat, and two of these were sequenced from the transcriptome. The expression of MSH2 was studied using qPCR in the transcriptome of Cadenza and four gamma-irradiated deletion lines, generated in a Paragon background. The four deletion lines showed varying responses: from down-regulation of MSH2 expression by 57% to upregulation by 82%. The expression of the individual homoeologues of MSH2 were also explored using a qPCR based method and by examining RNAseq data, but this was inconclusive.

Chondrocytes are the cells of articular cartilage responsible for the production and maintenance of their extracellular matrix (ECM). They exist in a unique environment of low partial pressures of oxygen, low pH and avascularity (Urban, 1994). The chondrocyte environment is also challenged by constant osmotic fluxes during osmolarity changes induced by joint loading. This thesis investigates the ion channels expressed by chondrocytes and examines the possible functions for these channels. Whole cell and single channel electrophysiological experiments identified chloride, sodium, potassium and non-selective cation conductances in isolated canine chondrocytes. Whole-cell current clamp measurements of membrane potential (Vm) showed that chondrocytes have very depolarised Vm compared to other cell types (in the range of -8 to -14mV, measured from bovine, ovine, equine and canine chondrocytes). Permeability experiments carried out in whole-cell voltage clamp mode determined that the non-selective cation current was selective for calcium over sodium and potassium at a level similar to that of the transient receptor potential vanilloid type five and six channels (TRPVS and 6). RT-PCR detected mRNA for TRPV4 and TRPVS channels. The effect of these channels on chondrocyte membrane potential (Vm) was determined using whole-cell current-clamp electrophysiology. Experiments with the selective TPRVS inhibitor econazole suggest that TRPVS is constitutively active and important for setting the depolarised Vm. Conversely, TRPV4 appeared to be inactive at rest and when activated by the selective agonist 4 a-phorbol 12,13-didecanoate indirectly caused an increase in potassium conductance and thus membrane hyperpolarisation. A low conductance sodium channel was also identified. Sensitivity to low concentrations of amiloride and benzamil indicate that this channel is the epithelial sodium channel (ENaC). Whole-cell current-clamp showed that this ENaC had a small but significant contribution to the Vm. A mixed population of chloride channels was found in the chondrocyte using single channel and whole-cell current and voltage clamp recordings. This population consisted of a maxi-chloride channel and a calcium-activated chloride channel. A model of chondrocyte Vm was then developed combining the approach of Hodgkin and Huxley (1952b) with parameters measured in the patch clamp experiments. This model was able to simulate many of the effects of inhibition of channel conductances on the resting membrane potential. Whole-cell current clamp experiments using inhibitors of the ion conductances discovered previously, verified the models predictions. This thesis then tested the hypothesis that the depolarised Vm of chondrocytes facilitates volume regulation. Cell volume experiments discovered that at more negative Vm chondrocytes were unable to regulate their volume upon hypotonic challenge. At more positive potentia Is, cell volume recovery was significantly greater. This is likely to be due to the greater driving force for potassium efflux and suggests that the depolarised Vm is an adaptation which allows the chondrocyte to effectively regulate its volume.

This project focuses on propaganda posters produced during the Second World War (1939 to 1945), primarily by the British government, aimed chiefly at their civilian population. The project uses Foucauldian discourse analysis and content analysis to investigate the images and their context, and identify key themes across a wide range of posters, over a long time-frame. This thesis contributes to an historical understanding of the British popular propaganda experience, largely ignored in previous historical research. Drawing on material from several archives, including the Imperial War Museum (IWM), the Public Record Office (PRO) and Mass-Observation (M-0), the project also uses questionnairest o elicit memorieso f the posters,a nd a poster databaset o collect together material which would otherwise remain dispersed. The thesis sets the posters against a background of contextual material, it identifies key propaganda theories, discerns relevant poster styles and recognises British poster style as one of pragmatic functionalism. The thesis outlines the poster production and distribution processeso f the Ministry of Information (MOI) and considers the first (highly criticised) posters before concentrating on four case studies, each of which is structured in three sections: the planning (context), the design, and the reception of the posters. The first case study examines what people were fighting for, and identifies their `imagined community', by considering urban and rural representations of the UK in the posters. The secondc ases tudy considersi ndustrial propaganda,e mphasisesth e idea of the island nation, and identifies those involved in the industrial effort. The third case study looks at the `enemy within', and examines who was excluded from, or was considered damaging to, the war effort. The fourth case study explores in detail who was compromising the war effort through their sexual behaviour, putting themselves at risk of venereal disease. The thesis argues that the posters drew heavily on longer term discourses emanating from new and established institutions, although there was often a clear distinction between those that drew on the past and tradition, and those that pushed forward to the future

Whisker samples were collected from grey seals from North Rona and from Isle of May in 1997-1999, from southern elephant seals from Pensinsular Valdes, Patagonia, from 1998 and 1999 and from South American sea lions also from Pensinsular Valdes in 1999. The whiskers were sub-sampled along their length and analysed for stable isotopes of δ(^13)C and δ(^15)N. There were significant differences between the two populations of grey seal and between years for each of the populations. Isotopic variations seen along the length of some of the whiskers were greater than could be attributed to background variation, indicating some seasonal variation. Possible prey items were herring, sandeels, some species of flat fish and gadoids. A strong temporal shift in apparent prey choice was seen only for the Isle of May, and the shift over a period of three years diminished the difference between the two populations. This could reflect changing prey choice or prey abundance in the North Sea over this time period. Male and female southern elephant seals showed significant differences in their isotopic values, with the male seals showing three different isotopic clusters that were distinct from one another and from the female seals. Two of these groups showed higher S'^C and §'^N values than those of the females and the third group. South American sea lions showed significantly higher values of δ(^13)C and δ(^15)N than female and most male southern elephant seals, suggesting that they were feeding at a higher trophic level. The South American sea lions and the group of male southern elephant seals with the highest values of δ(^13)C and δ(^15)N were possibly eating similar prey species which could include various fish and elasmobranch species. The female seals were feeding on prey with an isotopic signature similar to that of krill.

Institutional diversity is a long-held value in U.S. higher education with origins dating back 300 years to pre-Revolutionary colonial colleges. Institutional diversity is still valued today, but Institutional theory predicts that institutional organizations, such as universities, will homogenize without intervention to prevent loss of diversity. Multi-campus systems should guard against homogenization as their primary function is to define the missions of constituent universities and ensure diversity throughout the system. Working under the assumptions of Institutional theory and the functional tenets of a multi-campus system, the purpose of this study was twofold; to determine if public universities in Texas were homogenizing with regard to institutional mission and to explore the multi-campus systems' role in the condition of institutional diversity among constituent universities. The objectives of the study were accomplished using a two-part mixed methods research approach that examined the time period from 1990 to 2010. In Part I, three hypotheses and regional competition were tested to determine the state of institutional diversity among Texas public universities. The variables representing the various aspects of a university's mission are program duplication rates; proportion of graduate programs out of total programs; research expenditures; first-time, freshmen admission rates; and the rate of first-time, freshmen applicants from the top 10% of their high school class. Simple OLS analysis was used to examine Hypothesis 1 to determine if changes in the variables for each university were significantly correlated with time and if the universities were becoming more like one another. Hypothesis 2 examined whether non-research universities were homogenizing toward research universities. Hypothesis 3 examined whether membership in a multi-campus system reduced homogenization. A series of two proportions, two-tailed z-tests were used to test Hypotheses 2 and 3 by comparing the variables between the sub-groups of universities. After the comparisons were conducted, analysis entailed looking for patterns in the similarities and differences of the comparisons. Regional competition among universities in close geographic proximity was examined using simple OLS analysis where comparisons among universities were done on a regional basis within the Dallas-Fort Worth and Austin-San Antonio regions. Part II of the study explored the multi-campus systems' role in promoting diversity among constituent universities through the examination of multi-campus systems' decisions and discussions recorded in the respective board of regent meeting minutes. A basic interpretive analysis was used to find explicit or implicit evidence that multi-campus systems were aware of their role in promoting institutional diversity as well as evidence that multi-campus systems were actively promoting institutions diversity among constituent universities. Four key findings emerged from the analyses of the research hypotheses; regional competition; and the examination of the multi-campus systems' board of regent meeting minutes: 1) homogenization has occurred among the universities within this study; 2) non-research universities have not become like the research universities in this study; 3) multi-campus systems are not consistently preventing homogenization and in some cases are encouraging it; and 4) Institutional theory's isomorphic pressures do not adequately explain the homogenization observed in this study. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

The electrophysiological variation of RBCs and platelets is intriguing, as both are anucleate and lack traditional cellular apparatus; their behaviour is driven by the ion channels within the membrane. Assessment and characterisation of the electrophysiological rhythms of red blood cells (RBCs), and the observation of similar rhythms in platelets, is potentially of importance due to the temporal incidence of many diseases associated with these cell types. RBCs and platelets were examined using various methods including dielectrophoresis, flow cytometry, and zeta potential to assess for rhythmic properties. This work demonstrates that casein kinase is involved in RBC electrophysiological rhythms. Inhibition of casein kinase in RBCs altered the observed rhythm, revealing its involvement in both RBC electrophysiological rhythms and temperature compensation. The possible roles of intrinsic and extrinsic factors in RBC electrophysiological rhythms were examined. Levels of haemoglobin, ionic abundance, and passive electrophysiology were found to show time of day variation. Furthermore, zeta potential was used as a novel method to examine rhythmic electrophysiology. This thesis provides the first evidence of the presence of electrophysiological rhythms in platelets. Platelet electrophysiology was assessed in: platelet rich plasma immediately after venepuncture, stored platelet rich plasma, and stored resuspended platelets. Each condition exhibited a rhythm of differing period, suggesting the platelet entrainment mechanism involves at least three components: an intrinsic platelet component, entraining plasma component, and endogenous circulation component. Furthermore, activated platelets showed altered rhythms in each condition, suggesting the presence of an additional clock, functioning on platelet activation. The electrophysiological rhythm of a platelet precursor cell line was examined (in the assessment of the origin of platelet rhythms) and was found to be different to that of platelets.