Sentence Topic in Comment Articles

[Abstract] Although it competes with subject and theme as a key concept within the field of discourse analysis, there is much to be gained by utilising the sophisticated treatment of sentence topic developed by theorists working within the frameworks of functional and cognitive grammar. The claim that there is a tendency for sentence topics to coincide with grammatical subjects and familiar referents is examined in relation to texts drawn from two different genres and text-types. It is argued that the alignment of topic and grammatical subject may be more clear-cut in brief expository biographical notes than in longer argumentative comment articles, where clarity and coherence may not be the primary objective. Finally, it is suggested that the preference for sentence topics and familiar referents to be realized by grammatical subjects might vary according to texttype and genre

Factorization Properties of Leamer Monoids

The Huneke-Wiegand conjecture has prompted much recent research in Commutative Algebra. In studying this conjecture for certain classes of rings, Garc\'ia-S\'anchez and Leamer construct a monoid S_\Gamma^s whose elements correspond to arithmetic sequences in a numerical monoid \Gamma of step size s. These monoids, which we call Leamer monoids, possess a very interesting factorization theory that is significantly different from the numerical monoids from which they are derived. In this paper, we offer much of the foundational theory of Leamer monoids, including an analysis of their atomic structure, and investigate certain factorization invariants. Furthermore, when S_\Gamma^s is an arithmetical Leamer monoid, we give an exact description of its atoms and use this to provide explicit formulae for its Delta set and catenary degree

The role of T-lymphocytes in the pathogenesis of dengue haemorrhagic fever

Dengue is one of the most important human diseases transmitted by an arthropod vector and the incidence of dengue virus infection has been increasing steadily throughout the world. Most infections are asymptomatic but a subset of patients experience a potentially fatal shock syndrome characterised by plasma leakage. Generally attributed to the phenomenon of antibody-dependent enhancement, recent observations indicate that T cells may influence the development of this disease and it is this arm of the immune response to dengue this thesis examines. It starts by describing the production of novel HLA "tetramers" required for the work and then examines the role played by CD8+ cytotoxic T lymphocytes (CTL). This work demonstrates that CTL showing high level cross reactivity between dengue serotypes tend to exhibit high avidity and can be expanded from blood samples taken during the acute phase of secondary dengue infection. These cells produce much higher levels of both type 1 and certain type 2 cytokines than more serotype specific populations. Highly cross-reactive cells cannot be detected in convalescence when populations demonstrating significant serotype specificity dominate. The next section of the thesis describes the generation and characterisation of dengue specific CD4+ T cell clones, many of which behave in a highly cross-reactive manner producing large amounts of type 1 cytokines and demonstrating perforin-mediated cytolytic activity associated with an increase in the expression of surface CD107. It debates whether a new epitope has been discovered and discusses the nature of CD4 degeneracy, and its contribution to early cross-reactive immune responses which may facilitate priming of other immune system components. In conclusion this thesis hypothesises that sequential infection with different dengue virus serotypes elicits highly activated, cross-reactive CTL from memory which produce high levels of pro-inflammatory cytokines. Dengue-specific cross-reactive CD4+ T cell populations are also generated from memory and are capable of producing even greater levels of pro-inflammatory cytokines, and perhaps priming other cell populations. These mediators lead to the development of fluid leak and shock. High-avidity CD8+ T cells are subsequently deleted, perhaps as a consequence of activation-induced cell death, and a more beneficial serotype-specific memory CTL pool generated. These observations have significant implications for our understanding of the role of virus-specific CTL in pathogenesis of dengue disease and consequently for the design of a safe, effective vaccine

NEW, MULTI-SCALE APPROACHES TO CHARACTERIZE PATTERNS IN VEGETATION, FUELS, AND WILDFIRE

Pattern and scale are key to understanding ecological processes. My dissertation research aims for novel quantification of vegetation, fuel, and wildfire patterns at multiple scales and to leverage these data for insights into fire processes. Core to this motivation is the 3-dimensional (3-D) characterization of forest properties from light detection and ranging (LiDAR) and structure-from-motion (SfM) photogrammetry. Analytical methods for extracting useable information currently lag the ability to collect such 3-D data. The chapters that follow focus on this limitation blending interests in machine learning and data science, remote sensing, wildland fuels (vegetation), and wildfire. In Chapter 2, forest canopy structure is characterized from multiple landscapes using LiDAR data and a novel data-driven framework to identify and compare structural classes. Motivations for this chapter include the desire to systematically assess forest structure from landscape to global scales and increase the utility of data collected by government agencies for landscape restoration planning. Chapter 3 endeavors to link 3-D canopy fuels attributes to conventional optical remote sensing data with the goal of extending the reach of laser measurements to the entire western US while exploring geographic differences in LiDAR-Landsat relationships. Development of predictive models and resulting datasets increase accuracy and spatial variation over currently used canopy fuel datasets. Chapters 4 and 5 characterize fire and fuel variability using unmanned aerial systems (UAS) and quantify trends in the influence of fuel patterns on fire processes

The residential school; some aspects of the physical and social environment

This thesis considers the environment of mainstream residential schools largely from the viewpoint of the pupils' perception. The nature of the physical environment and in particular the evolution of the built environment is discussed in detail. The temporal element is not forgotten in this context, as major influences, be they personalities or trends are assessed for their impact. The second major element of the environment is then considered, being the social climate. A whole range of factors are assessed for the level of impact in terms of their influence on the atmosphere of a residential school. The role of Government, and in particular the impact of the Children Act.(1989), is covered in detail. The range of areas where the legislation impinges on the form of the physical environment is discussed. Behaviorialism as an approach to the study of the perception of the environment is developed as a concept. The major trends in developing an approach to perceptual studies are traced and individual contributors are given due recognition. From this a field programme is created, drawing upon ideas employed in the past for the assessment of the environment. The field programme is applied to a variety of residential schools, which declare themselves to have a distinctive ethos. The field programme is completed by the pupils in the schools in order to assess their perception of the effectiveness of the school environment in their educational experience. Fifteen case studies are detailed to illustrate specific points of contrast between schools. The mean school for comparative purposes is calculated and recommendations for the improvement and development of the whole residential school environment are made