Synthesis and multinuclear magnetic resonance studies of some nitrogen-containing ceramic phases

This Thesis describes the synthesis of a range of sialon ceramic phases, and their characterisation using multinuclear magnetic resonance and powder X-ray diffraction.Sihcon-29 and aluminium-27 MAS NMR spectroscopies have been used in the past on a range of inorganic systems, with considerable success. In this study, they were applied to phases in M-Si-Al-O-N systems, with M=La, Y, Li, Mg and Ca, leading to an improved understanding of the factors affecting chemical shifts and other NMR parameters. It was found that some structural information on, for example, 0/N ordering was not available from (^29)Si and (^27)Al NMR, but could be obtained from studies of other nuclei. Nitrogen-15 and oxygen-17 were selected for further study. The low natural abundances of these nuclei meant that isotopically enriched materials had to be prepared. The synthesis of a-Si(^15)(_3)N(_4), Mg(^17)O and Si(^17)O(_2), and of enriched sialon materials is described, and also (^15)N and (^17)0 MAS NMR studies of many sialon phases. In particular, the (^15)N and (^29)Si spectra of lanthanum new phase, a phase of previously unknown structure, were combined with a Patterson map from powder XRD data to allow the crystal structure of this phase to be determined. Finally, the feasibility of using other nuclei to study ceramic structures has been investigated, and (^9)Be, (^7)Li and (^139)La NMR spectra of several phases are reported

An evidence-based health workforce model for primary and community care

<p>Abstract</p> <p>Background</p> <p>The delivery of best practice care can markedly improve clinical outcomes in patients with chronic disease. While the provision of a skilled, multidisciplinary team is pivotal to the delivery of best practice care, the occupational or skill mix required to deliver this care is unclear; it is also uncertain whether such a team would have the capacity to adequately address the complex needs of the clinic population. This is the role of needs-based health workforce planning. The objective of this article is to describe the development of an evidence-informed, needs-based health workforce model to support the delivery of best-practice interdisciplinary chronic disease management in the primary and community care setting using diabetes as a case exemplar.</p> <p>Discussion</p> <p>Development of the workforce model was informed by a strategic review of the literature, critical appraisal of clinical practice guidelines, and a consensus elicitation technique using expert multidisciplinary clinical panels. Twenty-four distinct patient attributes that require unique clinical competencies for the management of diabetes in the primary care setting were identified. Patient attributes were grouped into four major themes and developed into a conceptual model: the Workforce Evidence-Based (WEB) planning model. The four levels of the WEB model are (1) promotion, prevention, and screening of the general or high-risk population; (2) type or stage of disease; (3) complications; and (4) threats to self-care capacity. Given the number of potential combinations of attributes, the model can account for literally millions of individual patient types, each with a distinct clinical team need, which can be used to estimate the total health workforce requirement.</p> <p>Summary</p> <p>The WEB model was developed in a way that is not only reflective of the diversity in the community and clinic populations but also parsimonious and clear to present and operationalize. A key feature of the model is the classification of subpopulations, which gives attention to the particular care needs of disadvantaged groups by incorporating threats to self-care capacity. The model can be used for clinical, health services, and health workforce planning.</p

An alternative method of endotracheal intubation of common marmosets (Callithrix jacchus)

Peer reviewe

Testing the human factor: Radiocarbon dating the first peoples of the South Pacific

Archaeologists have long debated the origins and mode of dispersal of the immediate predecessors of all Polynesians and many populations in Island Melanesia. Such debates are inextricably linked to a chronological framework provided, in part, by radiocarbon dates. Human remains have the greatest potential for providing answers to many questions pertinent to these debates. Unfortunately, bone is one of the most complicated materials to date reliably because of bone degradation, sample pretreatment and diet. This is of particular concern in the Pacific where humidity contributes to the rapid decay of bone protein, and a combination of marine, reef, C₄, C₃ and freshwater foods complicate the interpretation of ¹⁴C determinations. Independent advances in bone pretreatment, isotope multivariate modelling and radiocarbon calibration techniques provide us, for the first time, with the tools to obtain reliable calibrated ages for Pacific burials. Here we present research that combines these techniques, enabling us to re-evaluate the age of burials from key archaeological sites in the Pacific

Electricity Network Scenarios for Great Britain in 2050

The next fifty years are likely to see great developments in the technologies deployed in electricity systems, with consequent changes in the structure and operation of power networks. This paper, which forms a chapter in the forthcoming book Future Electricity Technologies and Systems, develops and presents six possible future electricity industry scenarios for Great Britain, focussed on the year 2050. The paper draws upon discussions of important technologies presented by expert authors in other chapters of the book to consider the impact of different combinations of key influences on the nature of the power system in 2050. For each scenario there is a discussion of the effects of the key parameters, with a description and pictorial illustration. Summary tables identify the role of the technologies presented in other chapters of the book, and list important figures of interest, such as the capacity and energy production of renewable generation technologies

The role of social norms in incentivising energy reduction in organisations

This study was part of a collaborative trial for an energy feedback intervention, providing detailed individual desk based energy feedback information to help individuals reduce energy in an office environment. Although the intervention was individually based, this paper explores the social context in which the intervention took place, and in particular attempted to measure changes in normative influence (descriptive and injunctive norms) around specific energy services, before and after the intervention. Results from the study identified that social norms around certain energy services changed as a result of the intervention, and the level of descriptive norms was found to have an effect on the energy efficiency of participants. Additionally interviews which were carried out during the study are insightful in helping understand how norms emerge and spread with the influence of social context and related factors. Interviews indicate strong interactions between technologies/technology policy and social context. The findings are highly relevant in the current age of fast paced technology change where businesses and governments often make decisions on what ICT technologies shall be introduced and used (such as smart metering), without fully considering the two way relationship between these technologies and social context

Variability in the lower circumpolar deep water and the Lazarev Sea

Furthering our understanding of the Southern Ocean as a critical component of the global climate system and its variability in both space and time is the focus of many investigations. This thesis aims to add to that effort by addressing two important questions. The first chapter will set the role of the Southern Ocean into greater context, clarifying the framework and background for its examination. The second chapter will examine a simple 1-dimensional model of the modification of the Lower Circumpolar Deep Water as it moves southwards across the ACC and into the Weddell Gyre. This leads into the third chapter which will address the first question of how variable are the characteristics of the Lower Circumpolar Deep Water? The variability of the salinity maximum associated with the Lower Circumpolar Deep Water is examined in order to address its spatial variability – from entry via the South Atlantic, through its circumpolar transit, ending with a terminal repository in the Weddell Gyre – by making use of freely available hydrographic data. It also examines temporal variability where repeat data allows, and provides new estimates of deep ocean mixing rates. The fourth chapter will seek to address the second question of how variable was the volume transport during the Lazarev Sea Krill Study (LaKriS) cruises? The LaKriS cruises provide a rare set of semi-repeat grids of hydrographic measurements near the Greenwich Meridian. This provides the opportunity to attempt to assess seasonal and inter-annual variability by making use of an inverse modelling technique. The fifth and final chapter will set the knowledge gained from addressing these two questions against the wider knowledge of the Southern Ocean system and consider the implications for future oceanic sampling and research

Ubiquitin/SUMO modification of PCNA promotes replication fork progression in Xenopus laevis egg extracts

The homotrimeric DNA replication protein proliferating cell nuclear antigen (PCNA) is regulated by both ubiquitylation and sumoylation. We study the appearance and the impact of these modifications on chromosomal replication in frog egg extracts. Xenopus laevis PCNA is modified on lysine 164 by sumoylation, monoubiquitylation, and diubiquitylation. Sumoylation and monoubiquitylation occur during the replication of undamaged DNA, whereas diubiquitylation occurs specifically in response to DNA damage. When lysine 164 modification is prevented, replication fork movement through undamaged DNA slows down and DNA polymerase δ fails to associate with replicating chromatin. When sumoylation alone is prevented, replication occurs normally and neither monoubiquitylation nor sumoylation are required for the replication of simple single-strand DNA templates. Our findings expand the repertoire of functions for PCNA ubiquitylation and sumoylation by elucidating a role for these modifications during the replication of undamaged DNA. Furthermore, they suggest that PCNA monoubiquitylation serves as a molecular gas pedal that controls the speed of replisome movement during S phase

Effects of defocus on the transfer function of coherence scanning interferometry

Coherence scanning interferometry (CSI) offers three dimensional (3D) measurement of surface topography with high precision and accuracy. Defocus within the interferometric objective lens, however, is commonly present in CSI measurements, and reduces both the resolving power of the imaging system and the ability to measure tilted surfaces. This paper extends the linear theory of CSI to consider the effects of defocus on the 3D transfer function and the point spread function in an otherwise ideal CSI instrument. The results are compared with measurements of these functions in a real instrument. This work provides further evidence for the validity of the linear systems theory of CSI