4 resultados para strength and function

em Glasgow Theses Service


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This study concerns the manuscript music book of Robert Edward (c. 1614–c. 1697), minister, author and musician. The manuscript, formerly part of the library at Panmure House, is now held in the National Library of Scotland and is commonly referred to as ‘Robert Edward’s Commonplace Book’ (GB-En MS.9450). The present study is in two parts and begins with an exploration of the physical book, including the structure, compilation, hands and ownership before a second chapter explores the biography of the eponymous owner, contextualising GB-En MS.9450 locally and nationally. The third chapter concerns the function of the manuscript which, it is argued, is closely related to pedagogy. The final three chapters discuss the content of the manuscript, taking in turn the vocal music, instrumental music and the selection of Italian three-part villanelle. The implications for dating and use arising from the first part of this

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This thesis explores two distinct parts of mitochondrial physiology: the role of mitochondria in generation of reactive oxygen species (ROS) and mitochondrial morphology and dynamics within cells. The first area of research is covered in Chapters 1-8. Mitochondrial biofunctionality and ROS production are discussed in Chapter 1, followed by the strategy of targeting bioactive compounds to mitochondria by linking them to lipophilic triphenylphosphonium cations (TPP) (Chapter 2). ROS sensors relevant to the research are reviewed in Chapter 3. Chapter 4 presents design and synthesis of novel probes for superoxide detection in mitochondria (MitoNeo-D), cytosol (Neo-D) and extracellular environment (ExCellNeo-D). The results of biological validation of MitoNeo-D and Neo-D performed in the MRC MBU in Cambridge are presented in Chapter 5. A dicationic hydrogen peroxide sensor that utilizes in situ click chemistry is discussed in Chapter 6. Preliminary work on the synthesis of mitochondria-targeted superoxide generators, which led to the development of mitochondria-targeted analogue of paraquat, MitoPQ, is presented in Chapter 7. A set of bifunctional probes (BCN-Mal, BCN-E-BCN and Mito-iTag) for assessing the redox states of protein thiols is discussed in Chapter 8 along with their biological validation. The second part of the thesis is aimed at the study of mitochondrial morphology and dynamics and is presented in Chapters 9-11. Chapter 9 provides background on the classes of fluorophores relevant to the research, the phenomenon of fluorescence quenching and the principle of photoactivation with examples of photoactivatable fluorophores. Next, the background on mitochondrial morphology and heterogeneity is presented in Chapter 10, followed by the ways of imaging and tracking mitochondria within cells by conventional fluorophores and by photoactivatable fluorophores exploiting super-resolution microscopy. Chapter 11 presents the design and synthesis of four photoactivatable fluorophores for mitochondrial tracking, MitoPhotoRhod110, MitoPhotoNIR, Photo-E+, MitoPhoto-E+, along with results of biological validation of MitoPhotoNIR. The results and discussion concludes with Chapter 12, which is a summary and suggestions for future work, followed by the chemistry experimental procedures (Chapter 13), materials and methods for biological experiments (Chapter 14) and references.

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This thesis focuses on the history of the inflexional subjunctive and its functional substitutes in Late Middle English. To explore why and how the inflexional subjunctive declined in the history of English language, I analysed 2653 examples of three adverbial clauses introduced by if (1882 examples), though (305 examples) and lest (466 examples). Using a corpus-based approach, this thesis argues that linguistic change in subjunctive constructions did not happen suddenly but rather gradually, and the way it changed was varied , and that different constructions changed at different speeds in different environments. It is well known that the inflexional subjunctive declined in the history of English, mainly because of inflexional loss. Strangely however this topic has been comparatively neglected in the scholarly literature, especially with regard to the Middle English period, probably due to the limitations of data and also because study of this development requires very cumbersome textual research. This thesis has derived and analysed the data from three large corpora in the public domain: the Middle English Grammar Corpus (MEG-C for short), the Innsbruck Computer Archive of Machine-Readable English Texts (ICAMET for short), and some selected texts from The Corpus of Middle English Prose and Verse, part of the Middle English Compendium that also includes the Middle English Dictionary. The data were analysed from three perspectives: 1) clausal type, 2) dialect, and 3) textual genre. The basic methodology for the research was to analyse the examples one by one, with special attention being paid to the peculiarities of each text. In addition, this thesis draw on some complementary – indeed overlapping -- linguistic theories for further discussion: 1) Biber’s multi-dimensional theory, 2) Ogura and Wang’s (1994) S-curve or ‘diffusion’ theory, 3) Kretzchmar’s (2009) linguistics of speech, and 4) Halliday’s (1987) notion of language as a dynamic open system. To summarise the outcomes of this thesis: 1) On variation between clausal types, it was shown that the distributional tendencies of verb types (sub, ind, mod) are different between the three adverbial clauses under consideration. 2) On variation between dialects, it has been shown that the northern area, i.e. the so-called Great Scandinavian Belt, displays an especially high comparative ratio of the inflexional subjunctive construction compared to the other areas. This thesis suggests that this result was caused by the influence of Norse, relating the finding to the argument of Samuels (1989) that the present tense -es ending in the northern dialect was introduced by the influence of the Scandinavians. 3) On variation between genres, those labelled Science, Documents and Religion display relatively high ratio of the inflexional subjunctive, while Letter, Romance and History show relatively low ratio of the inflexional subjunctive. This results are explained by Biber’s multi-dimensional theory, which shows that the inflexional subjunctive can be related to the factors ‘informational’, ‘non-narrative’, ‘persuasive’ and ‘abstract’. 4) Lastly, on the inflexional subjunctive in Late Middle English, this thesis concludes that 1) the change did not happen suddenly but gradually, and 2) the way language changes varies. Thus the inflexional subjunctive did not disappear suddenly from England, and there was a time lag among the clausal types, dialects and genres, which can be related to Ogura and Wang’s S-curve (“diffusion”) theory and Kretzchmars’s view of “linguistic continuum”. This thesis has shown that the issues with regard to the inflexional subjunctive are quite complex, so that research in this area requires not only textual analysis but also theoretical analysis, considering both intra- and extra- linguistic factors.

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During pregnancy, the maternal cardiovascular system undergoes major adaptation. One of these changes is a 40-50 % increase in circulating blood volume which requires a systemic remodelling of the vasculature in order to regulate maternal blood pressure and maximise blood supply to the developing placenta and fetus. These changes are broadly conserved between humans and rats making them an appropriate pre-clinical model in which to study the underlying mechanisms of pregnancy-dependent cardiovascular remodelling. Whilst women are normally protected against cardiovascular disease; pregnancy marks a period of time where women are susceptible to cardiovascular complications. Cardiovascular disease is the leading cause of maternal mortality in the United Kingdom; in particular hypertensive conditions are among the most common complications of pregnancy. One of the main underlying pathologies of these pregnancy complications is thought to be a failure of the maternal cardiovascular system to adapt. The remodelling of the uterine arteries, which directly supply the maternal-fetal interface, is paramount to a healthy pregnancy. Failure of the uterine arteries to remodel sufficiently can result in a number of obstetric complications such as preeclampsia, fetal growth restriction and spontaneous pregnancy loss. At present, it is poorly understood whether this deficient vascular response is due to a predisposition from existing maternal cardiovascular risk factors, the physiological changes that occur during pregnancy or a combination of both. Previous work in our group employed the stroke prone spontaneously hypertensive rat (SHRSP) as a model to investigate pregnancy-dependent remodelling of the uterine arteries. The SHRSP develops hypertension from 6 weeks of age and can be contrasted with the control strain, the Wistar Kyoto (WKY) rat. The phenotype of the SHRSP is therefore reflective of the clinical situation of maternal chronic hypertension during pregnancy. We showed that the SHRSP exhibited a deficient uterine artery remodelling response with respect to both structure and function accompanied by a reduction in litter size relative to the WKY at gestational day (GD) 18. A previous intervention study using nifedipine in the SHRSP achieved successful blood pressure reduction from 6 weeks of age and throughout pregnancy; however uterine artery remodelling and litter size at GD18 was not improved. We concluded that the abnormal uterine artery remodelling present in the SHRSP was independent of chronic hypertension. From these findings, we hypothesised that the SHRSP could be a novel model of spontaneously deficient uterine artery remodelling in response to pregnancy which was underpinned by other as yet unidentified cardiovascular risk factors. In Chapter 1 of this thesis, I have characterised the maternal, placental and fetal phenotype in pregnant (GD18) SHRSP and WKY. The pregnant SHRSP exhibit features of left ventricular hypertrophy in response to pregnancy and altered expression of maternal plasma biomarkers which have been previously associated with hypertension in human pregnancy. I developed a protocol for accurate dissection of the rat uteroplacental unit using qPCR probes specific for each layer. This allowed me to make an accurate and specific statement about gene expression in the SHRSP GD18 placenta; where oxidative stress related gene markers were increased in the vascular compartments. The majority of SHRSP placenta presented at GD18 with a blackened ring which encircled the tissue. Further investigation of the placenta using western blot for caspase 3 cleavage determined that this was likely due to increased cell death in the SHRSP placenta. The SHRSP also presented with a loss of one particular placental cell type at GD18: the glycogen cells. These cells could have been the target of cell death in the SHRSP placenta or were utilised early in pregnancy as a source of energy due to the deficient uterine artery blood supply. Blastocyst implantation was not altered but resorption rate was increased between SHRSP and WKY; indicating that the reduction in litter size in the SHRSP was primarily due to late (>GD14) pregnancy loss. Fetal growth was not restricted in SHRSP which led to the conclusion that SHRSP sacrifice part of their litter to deliver a smaller number of healthier pups. Activation of the immune system is a common pathway that has been implicated in the development of both hypertension and adverse pregnancy outcome. In Chapter 2, I proposed that this may be a mechanism of interest in SHRSP pregnancy and measured the pro-inflammatory cytokine, TNFα, as a marker of inflammation in pregnant SHRSP and WKY and in the placentas from these animals. TNFα was up-regulated in maternal plasma and urine from the GD18 SHRSP. In addition, TNFα release was increased from the GD18 SHRSP placenta as was the expression of the pro-inflammatory TNFα receptor 1 (Tnfr1). In order to investigate whether this excess TNFα was detrimental to SHRSP pregnancy, a vehicle-controlled intervention study using etanercept (a monoclonal antibody which works as a TNFα antagonist) was carried out. Etanercept treatment at GD0, 6, 12 and 18 resulted in an improvement in pregnancy outcome in the SHRSP with an increased litter size and reduced resorption rate. Furthermore, there was an improved uterine artery function in GD18 SHRSP treated with etanercept which was associated with an improved uterine artery blood flow over the course of gestation. In Chapter 3, I sought to identify the source of this detrimental excess of TNFα by designing a panel for maternal leukocytes in the blood and placenta at GD18. A population of CD3- CD161+ cells, which are defined as rat natural killer (NK) cells, were increased in number in the SHRSP. Intracellular flow cytometry also identified this cell type as a source of excess TNFα in blood and placenta from pregnant SHRSP. I then went on to evaluate the effects of etanercept treatment on these CD3- CD161+ cells and showed that etanercept reduced the expression of CD161 and the cytotoxic molecule, granzyme B, in the NK cells. Thus, etanercept limits the cytotoxicity and potential damaging effect of these NK cells in the SHRSP placenta. Analysing the urinary peptidome has clinical potential to identify novel pathways involved with disease and/or to develop biomarker panels to aid and stratify diagnosis. In Chapter 4, I utilised the SHRSP as a pre-clinical model to identify novel urinary peptides associated with hypertensive pregnancy. Firstly, a characterisation study was carried out in the kidney of the WKY and SHRSP. Urine samples from WKY and SHRSP taken at pre-pregnancy, mid-pregnancy (GD12) and late pregnancy (GD18) were used in the peptidomic screen. In order to capture peptides which were markers of hypertensive pregnancy from the urinary peptidomic data, I focussed on those that were only changed in a strain dependent manner at GD12 and 18 and not pre-pregnancy. Peptide fragments from the uromodulin protein were identified from this analysis to be increased in pregnant SHRSP relative to pregnant WKY. This increase in uromodulin was validated at the SHRSP kidney level using qPCR. Uromodulin has previously been identified to be a candidate molecule involved in systemic arterial hypertension but not in hypertensive pregnancy thus is a promising target for further study. In summary, we have characterised the SHRSP as the first model of maternal chronic hypertension during pregnancy and identified that inflammation mediated by TNFα and NK cells plays a key role in the pathology. The evidence presented in this thesis establishes the SHRSP as a pre-clinical model for pregnancy research and can be continued into clinical studies in pregnant women with chronic hypertension which remains an area of unmet research need.