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    Development of a correction approach for future precipitation changes simulated by General Circulation Models

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    Producing reliable estimates of changes in precipitation at local- and regional-scales remains an important challenge in climate change science. Statistical downscaling methods are often utilised to bridge the gap between the coarse resolution of General Circulation Models (GCMs) and the higher-resolutions at which information is required by the majority of end users. However, the skill of GCM precipitation, particularly in simulating temporal variability, is not fully understood and statistical downscaling typically adopts a ‘Perfect-Prog’ (short for perfect prognosis) approach in which the derivation of high-resolution precipitation projections is based on real world statistical relationships between large-scale atmospheric ‘predictors’ and local-scale precipitation. Here, a ‘nudged’ simulation of the ECHAM5 GCM is conducted in which the large-scale climatic state is forced towards historical observations of large-scale circulation and temperature for the period 1958-2001. By comparing simulated and observed precipitation it is possible to, for the first time, quantify GCM skill in simulating temporal variability of precipitation. Correlation between simulated and observed monthly mean precipitation is shown to be as strong as 0.8-0.9 in many parts of Europe, North America and Australia. A nudged simulation permits the development of an alternative approach to statistical downscaling, known as Model Output Statistics (MOS), to correct precipitation as simulated by ECHAM5. It is also shown that MOS correction offers greater skill than Perfect-Prog methods when estimating local-scale monthly mean precipitation. The strongest-performing MOS models are applied to ECHAM5 climate change simulations and are shown to produce high-resolution precipitation projections that support those of RCM simulations. The potential for extending the MOS approach to daily precipitation is also assessed, with recommendations made for further research and application.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Exercise agency? : the role of elite actors in local democracy in English local government : the local democracy maker

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    The way in which employed senior elites in English local government exercise their agency in the practice of local democracy and local governance is considered in this thesis. The research posits the notion that elite Officers act as Local Democracy Makers as they draw on their own traditions and ideologies in responding to the dilemmas of changing policy and politics in the public realm. The study is located in the latter part of New Labour?s term of office and applies an interpretive and reflexive approach to three studies of the exercise of well being powers. The approach is one of applied ethnography through the examination of literature reviews, interviews and observations of decisions taken in the exercise of the powers of economic, environmental and social well-being are used to examine how and why the Local Democracy Makers make sense of their world in the way that they do. The research suggests that, despite prevailing narratives, local governance arrangements depend on a system of hierarchy, employed elites and local politics. The challenges of re-configuring local democracy and attempts at "hollowing out" the state have secured an influential role for the non-elected official. How officials interpret, advise, mediate and manage the exercise of local governance and local democracy presents a challenge to assumptions that public services are governed beyond or without local government. New narratives and reflections on the role of the local government Officer and the marginalisation of the elected Councillor are presented in the research. In particular, how the senior elite occupy managerial, strategic and political roles as Local Democracy Makers, offers an insight into the agency of strategic actors in localities. Consequently, the success of changes in public policy is materially influenced by how the practitioner responds to such dilemmas. The thesis concludes by suggesting that integral to the design and success of public policy implementation is the role of the Officer, and especially those practitioners that advise governing arrangements and democratic practice.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Investigating the genetic control of postharvest shelf life and vitamin C content in broccoli (Brassica oleracea var. italica)

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    Broccoli (Brassica oleracea var. italica) is a popular vegetable, known for its nutritional benefits. However, the marketability of broccoli is limited by a short shelf life. Broccoli is susceptible to rapid postharvest senescence, which causes visible head yellowing and wilting from dehydration. Visible quality loss is also accompanied by a decline in nutrients, resulting in a product with reduced postharvest nutritional value. These factors combined cause broccoli to become unmarketable, leading to severe wastage in the retail chain. Postharvest yellowing in broccoli has been shown to be controlled by genotype, as a doubled haploid population (MGDH) created from an F1 cross between GD33, a poor performing DH line (yellow in 2 days) and Mar34, a good performing DH line (staying green > 4 days) exhibited natural variation for shelf life. Therefore, to investigate the genetic control of quality in broccoli, the fixed mapping population was assessed for shelf life, morphological traits and vitamin C content and stability in replicated field trials. Visual inspections identified head yellowing, stem turgor and bud compactness as the main traits affecting the marketability of broccoli. Two methods to quantify head yellowing were also evaluated. Spectrophotometer readings were found to be more sensitive than Image J in detecting colour change, but Image J data was more reproducible. Vitamin C quantification using HPLC, confirmed that natural variation was present in the MGDH population at harvest. Vitamin C content during postharvest storage, detected by plate assays, found vitamin C to be unstable, degrading quickly after harvest. A unique broccoli x broccoli linkage map, covering ~72.9% of the B.oleracea genome, was also constructed by genotyping the MGDH population with SSR and AFLP markers. QTL analysis of the trait data positioned 48 significant QTL in the linkage map for head yellowing (4), colour co-ordinates (17), morphological traits (17), bud quality (2) and postharvest vitamin C content (3) and stability (5). The identification of QTLs associated with the above traits has provided useful information for breeders to breed for improved nutritional and quality in broccoli using marker-assisted selection (MAS). The location of QTLs has also provided targets for fine-scale mapping and for the identification of candidate genes underlying traits.EThOS - Electronic Theses Online ServiceBiotechnology and Biological Sciences Research Council (Great Britain) (BBSRC)GBUnited Kingdo

    Semantic information systems engineering : a query-based approach for semi-automatic annotation of web services

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    There has been an increasing interest in Semantic Web services (SWS) as a proposed solution to facilitate automatic discovery, composition and deployment of existing syntactic Web services. Successful implementation and wider adoption of SWS by research and industry are, however, profoundly based on the existence of effective and easy to use methods for service semantic description. Unfortunately, Web service semantic annotation is currently performed by manual means. Manual annotation is a difficult, error-prone and time-consuming task and few approaches exist aiming to semi-automate that task. Existing approaches are difficult to use since they require ontology building. Moreover, these approaches employ ineffective matching methods and suffer from the Low Percentage Problem. The latter problem happens when a small number of service elements - in comparison to the total number of elements – are annotated in a given service. This research addresses the Web services annotation problem by developing a semi-automatic annotation approach that allows SWS developers to effectively and easily annotate their syntactic services. The proposed approach does not require application ontologies to model service semantics. Instead, a standard query template is used: This template is filled with data and semantics extracted from WSDL files in order to produce query instances. The input of the annotation approach is the WSDL file of a candidate service and a set of ontologies. The output is an annotated WSDL file. The proposed approach is composed of five phases: (1) Concept extraction; (2) concept filtering and query filling; (3) query execution; (4) results assessment; and (5) SAWSDL annotation. The query execution engine makes use of name-based and structural matching techniques. The name-based matching is carried out by CN-Match which is a novel matching method and tool that is developed and evaluated in this research. The proposed annotation approach is evaluated using a set of existing Web services and ontologies. Precision (P), Recall (R), F-Measure (F) and Percentage of annotated elements are used as evaluation metrics. The evaluation reveals that the proposed approach is effective since - in relation to manual results - accurate and almost complete annotation results are obtained. In addition, high percentage of annotated elements is achieved using the proposed approach because it makes use of effective ontology extension mechanisms.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Financial intermediation and interest rate risk

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    This thesis analyses the link between interest rate risk faced by financial intermediaries in the G-10 countries, their balance sheet composition and national bank regulation. The regulatory authorities both in the US and in Europe increasingly emphasise the issue of bank interest rate exposure. The importance of this topic is also reasserted by recent developments in the monetary environment. The thesis offers three major contributions to the area. First, it empirically investigates the interest rate risk exposure of financial intermediaries across a large international data sample over the 1997 to 2009 time period. The results verify the importance of interest rate exposure for the majority of analysed institutions, with statistical inferences being robust to the choice of interest rate proxy, time period, and the adopted econometric methodology. Second, this research examines the underlying determinants of bank interest rate risk. Both company and market specific information is considered in the analysis. The findings suggest that national regulatory and supervisory characteristics, and notably international diversity among these provisions, are as important as firm-level accounting variables in explaining the interest rate exposures of individual banks. Finally, this work empirically addresses the impact of securitization on bank interest rate risk. In particular, the research questions whether securitization is conducive to the optimal hedging of bank interest rate risk, or is merely a funding source enabling these companies to pursue more profitable but riskier projects. The reported results imply that banks resorting to asset securitization do not, on average, achieve an unambiguous reduction in their exposure to the term structure developments.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    What is the appeal of poetry written for children for children? : a study of children's relationship with poetry

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    This thesis explores the appeal that a sample of children's poetry has for a group of thirty children in their final year of primary school in the United Kingdom. It examines this appeal within a socio-historical context that perceives literature written for children as playing an important role within a 'developmental state' (Lee, 2001) - a State where children are seen as sites of investment and as 'human becomings'. The thesis argues that the literature written for children forms part of the discourse that has historically attempted to define, manage and maintain contemporary conceptualisations of childhood. Within this context of adult society's ideological claim over literature written for children - including poetry - the study explores the nature of the appeal the texts generate for a class of ll-year olds. Through the use of a triangulation of case studies, the enquiry investigates how this appeal reflects children's own understanding of their childness (Hollindale, 1997). It will argue that although children's literature continues to be written for a variety of adult purposes, children are able to manage the messages and meanings found within the poetry and create their own pleasures from the texts with which they engage, rejecting those that they individually dislike.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    The power of feedback in professional learning

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    This longitudinal study explores the power and potential of feedback for expert professional learners. Feedback designed for professional learners has complex goals, including higher cognition, greater independence, increased perception within the field of activity and increased levels of reflection, both on and in action. Feedback definitions, which focus on improvement of product outcome, need to reflect the constructivist nature of giving and receiving information about learning. Feedback, as linked to assessment and evaluation practices, has roles for both teacher and learner. if feedback is to be optimally effective, its interaction with learner, learning environment, curriculum and teacher need to become understood through experience by learners in that context. The context of this study is a fulltime Master's programme for teacher educators at the Institute of Education, University of London. The findings, using data from interviews, course documents, field notes and written examples of feedback, demonstrate that feedback as a concept is somewhat uniquely constructed. This construction has the potential to either assist, or impede, or leave undisturbed the learning intentions of the feedback being understood and acted upon by the learner. Feedback can assist the process of perspective transformation. As learners learn, they are transformed, if feedback acts as catalyst to learning for knowledge construction, learning about the construction process itself and associated values in a given context. Therefore, feedback when perceived as a curriculum within a curriculum can provide a powerful means by which the goal of transformation is achieved. Feedback, as a socially situated practice, can operate as catalyst, process, product and curriculum when adopted in higher professional learning. The learning process, as knowledge and action, moves from the interpersonal to the intra-personal, with the feedback curriculum acting to enhance self assessment and self-directed learning, as learners actively seek and interpret feedback from the learning contexts which they lead.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Quantum metrology with Bose-Einstein condensates

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    The ability to make ultra-precise measurements is fundamentally important to science as it allows theories to be tested and refined. Interferometers offer unrivalled measurement precision and therefore form the basis of many metrology schemes. Research has shown that by using quantum states as inputs to interferometers, precisions better than anything possible classically can be achieved. Nevertheless, these states are difficult to produce and fragile to particle losses. Consequently, classical inputs, which are extremely robust, are used in experiments. Here, however, we propose experimentally accessible schemes to make quantum-limited measurements, in particular rotation measurements using Bose-Einstein condensates, that are robust to losses. We begin by describing how, by loading a Bose-Einstein condensate into an optical ring lattice, multiport beam splitters are created through a simple raising and lowering of potential barriers between sites. We then use these ‘splitters’ to create an atomic gyroscope. We demonstrate how to create several quantum states in the gyroscope, all capable of making rotation measurements. Whilst NOON states afford best precision in idealised set-ups, we find they are outperformed by ‘bat’ states for modest loss rates. However, bat states are not ideal as they are outperformed by classical states for large losses. A second gyroscope scheme is therefore developed. Using multiple momentum modes, rather than just two, we show quantum-limited precisions can be reached using states that have similar robustness to classical states. The final section focuses on the precision of linear interferometers. Recent work[1, 2] has calculated the theoretical optimum initial states for two-mode lossy interferometers. Here we present an experimental way to produce initial states that afford similar precisions to this optimum. We also consider lossy multimode interferometry and demonstrate a potential advantage over two-mode systems. It is thought with further investigation other advantages will be found.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    From the sublime to the ridiculous : top physics and minimum bias events in the ATLAS detector at the LHC

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    This thesis is comprised of two separate physics themes, both of which involve the ATLAS detector situated at the LHC at CERN. The first constituent is a study of the top quark signal in the fully-leptonic channel for proton-proton collisions at a centre-of-mass energy of 10 TeV. Here an event counting analysis is performed based on Monte Carlo simulation. This is supplemented by a study into one of the sources of systematic error. The second component is forward-backward correlations in minimum bias events. For this, there is a Monte Carlo hadron-level comparison of the correlation for 900 GeV centre-of-mass collisions, followed by a comparison of Monte Carlo predictions to data for 900 GeV and 7 TeV collisions. Top Physics A measurement of the fully-leptonic ttbar cross-section in the three decay channels ee, mumu, and emu is performed on ATLAS produced fully simulated pseudo-event data-samples. Selection rates for signal and background events consistent with ATLAS results are found along with the kinematic distributions of selected events. A calculation of the non-hadronic ttbar cross-section, based on the measured cross-sections, will then return the theoretical value of 217:06pb used to generate the original samples, showing the closure of the pseudo-analysis process. A more detailed study is made of the systematic uncertainty arising from variations in the initial (ISR) and final (FSR) state showering models, based on the Pythia event generator. A fast simulation of the ATLAS detector is used with similar object and event selection to the fully simulated case. The effect of ISR variations on the signal is found to be negligible as it is washed out in the subsequent decays of the ttbar system. However, the effect of FSR is found to cause 5% uncertainty in the selected signal events. In addition, in the main background of each of the selection channels the effect of FSR is found to produce variations of up to 30% in well populated channels. The variations in signal and background measurements will then be used to calculate a new estimate of the systematics on the measured ttbar cross-section for each channel. Minimum Bias A detailed study of the forward-backward (FB) correlation and event shapes of a selection of Pythia tunes for pp collisions with CoM = 900 GeV is performed. This includes an investigation into the sources of particle production in generated minimum bias events as well as the component sub-processes in generated minimum bias events. The tunes are found to be practically degenerate (within 10 - 20% variation) for the 'standard' distributions. The inclusion of a new observable, namely the forward-backward correlation, to the standard set is recommended. The study finds that the FB-correlation and its pT and dependent variations are able to discern differences between the selected tunes to a greater degree than the usual inclusive distributions. Further, the FB-correlation is found to be sensitive to the particle production processes within the tunes, an invaluable property for the purposes of generator tuning. A measurement of the forward-backward correlation for pp collision of CoM = 900 GeV and 7 TeV at the LHC using the ATLAS detector is made. The measured correlation is compared to the predicted correlation of several ATLAS centrally produced generator tunes. A correction procedure is developed and validated on the generator samples to correct the generated correlation to the hadron-level correlation. This is then applied to the measured correlation and a comparison of corrected data to the hadron-level predictions of the generated tunes made. The corrected correlations at the two collision energies are compared as well as the calculation of a global correlation at both energies. The measured and corrected correlations are found to lie above the predicted distributions at both energies and across the eta-range. Further investigation of measured correlation using augmented FB-correlations is recommended.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    The military activities of bishops, abbots and other clergy in England c.900-1200

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    This thesis examines the evidence for the involvement in warfare of clerks and religious in England between the beginning of the tenth century and the end of the twelfth. It focuses on bishops and abbots, whose military activities were recorded more frequently than lesser clergy, though these too are considered where appropriate. From the era of Christian conversion until long after the close of the middle ages, clergy were involved in the prosecution of warfare. In this period, they built fortresses and organised communities of warriors in time of peace and war. Some were slain in battle, while others were given promotion or lands for their martial exploits. A series of canonical pronouncements aimed to forbid or restrict the involvement of Christian clergy in organised bloodshed, and some writers branded militant clergy as corrupted by the lure of earthly power or even as having surrendered their sacerdotal status. This study therefore approaches the military practices of clergy alongside the legal and narrative treatments, and treats the latter as reactions to, not the background of, the former. This requires consideration of a wide range of narrative, diplomatic and legal source material. A broad approach shows that clerics’ military activities cannot be separated from their spiritual powers, that canonical treatment was more fragmented and less influential than has been assumed, and that the condemnations of some authors existed alongside others’ praise for clerics’ valour, loyalty, or commitment to defending their flocks. In consequence, the extended study of clerical participation in warfare is shown to have significant consequences for our conception of the bounds of military history, the construction of the licit and the illicit, and the nature of clerical identity itself.EThOS - Electronic Theses Online ServiceGBUnited Kingdo


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