171 research outputs found
Faithful semigroup diagram representations of homeomorphism groups
No full textIn this thesis we investigate two different classes of objects. The first is the class of Dénes cycles of a tree; we show a ‘strong’ correspondence between such cycles and certain partial orders on the edges of the tree. This allows us to find a slick new proof of a classical result, as well as give an algorithm for computing the multiplicity of a Dénes cycle. The second class of objects we investigate, and the main focus of this thesis, is groups generated by geometrically fast sets of bumps. We show that the class of such groups on the interval coincides with a certain subclass of diagram groups, and then exploit this connection to answer a question of Matthew Brin. We then go on to consider groups generated by fast bumps in a general setting and, in so doing, find a necessary and sufficient condition for when groups generated by fast sets of bumps on the circle are isomorphic to certain annular diagram groups. To finish, we deduce a couple of properties of fast groups of the interval using their diagram group representations. In aid of this, we define a group structure on infinite tree diagrams."The author has been partially funded by the EPSRC through the University of St Andrews doctoral training program during the creation of this thesis."--Acknowledgement
Data from: The application of optical coherence tomography to image subsurface tissue structure of Antarctic krill Euphausia superba
No full textMany small open ocean animals, such as Antarctic krill, are an important part of marine ecosystems. To discover what will happen to animals such as krill in a changing ocean, experiments are run in aquaria where conditions can be controlled to simulate water characteristics predicted to occur in the future. The response of individual animals to changing water conditions can be hard to observe, and with current observation techniques it is very difficult to follow the progress of an individual animal through its life. Optical coherence tomography (OCT) is an optical imaging technique that allows images at high resolution to be obtained from depths up to a few millimeters inside biological specimens. It is compatible with in vivo imaging and can be used repeatedly on the same specimens. In this work, we show how OCT may be applied to post mortem krill samples and how important physiological data such as shell thickness and estimates of organ volume can be obtained. Using OCT we find an average value for the thickness of krill exoskeleton to be (30±4) µm along a 1 cm length of the animal body. We also show that the technique may be used to provide detailed imagery of the internal structure of a pleopod joint and provide an estimate for the heart volume of (0.73±0.03) mm3. </span
Music made visible in time and space : concepts of simultaneity in tone-eurythmy choreography
No full textIncludes bibliographical references (leaves 105-113).Eurythmy is an art of movement that expresses music and speech. This dissertation explores eurythmy's musical field, called tone-eurythmy, in its multifaceted appearances, background and within its philosophical context. Tone-eurythmy, carried out by performers moving in space and time, makes music visible. It transforms music into a new movement-art form, that of audible-visible music, by expressing musical components as well as the artistic intentions within a composition and those held by the performing artists. The dissertation examines how musical concepts are seen by eurythmists to integrate ideas of wholeness and to understand music as both audible and inaudible. It draws on studies and findings from music psychology to show distinct effects of musical elements on the human being, and to indicate the similarities between those and the qualitative expressions of music through tone-eurythmy
The application of optical coherence tomography to image subsurface tissue structure of Antarctic krill Euphausia superba
No full textMany small open ocean animals, such as Antarctic krill, are an important part of marine ecosystems. To discover what will happen to animals such as krill in a changing ocean, experiments are run in aquaria where conditions can be controlled to simulate water characteristics predicted to occur in the future. The response of individual animals to changing water conditions can be hard to observe, and with current observation techniques it is very difficult to follow the progress of an individual animal through its life. Optical coherence tomography (OCT) is an optical imaging technique that allows images at high resolution to be obtained from depths up to a few millimeters inside biological specimens. It is compatible with in vivo imaging and can be used repeatedly on the same specimens. In this work, we show how OCT may be applied to post mortem krill samples and how important physiological data such as shell thickness and estimates of organ volume can be obtained. Using OCT we find an average value for the thickness of krill exoskeleton to be (30±4) µm along a 1 cm length of the animal body. We also show that the technique may be used to provide detailed imagery of the internal structure of a pleopod joint and provide an estimate for the heart volume of (0.73±0.03) mm3
Music for classical guitar by South African composers : a historical survey, notes on selected works and a general catalogue
No full textIncludes abstract.Includes bibliographical references (leaves 296-309).This is the first comprehensive investigation of music for, or including, the classical guitar by South African composers. The focus of this research has been, firstly, to uncover as much of the repertoire as possible, and, secondly, to collate, study, catalogue and report on the information. A brief historical survey of the guitar in South Africa provides the context within which this study was conducted. The primary sources of quantitative data collection were through the archival catalogues of the South African Music Rights Organisation and through personal contact with guitarists, composers and guitar teachers. Other sources consulted were publishers, broadcasting corporations, recording companies, libraries and the internet. The body of the dissertation comprises biographical sketches, background notes, analyses and technical notes on 17 selected solo and chamber works dating from 1947 to 2007 by some of South Africa's most prominent composers and guitaristcomposers. The repertoire ranges in style from the traditional and ethnically inspired to the experimental and abstract. As this is an empirical survey, each selected entry includes details on instrumentation, duration, level of difficulty, number of pages, scordatura, commissions or requests, sources or publishers, premières and recordings. A biography of each composer is provided as well as background notes which offer an overview of the selected work. The notes discuss historical, cultural, musical and extra-musical influences, and frequently include references to interview material. The commentaries on the selected works, with musical examples, include an analytical component describing structure, form, stylistic and compositional elements, while the technical observations include performance suggestions and a grading for each work
Improved Methods for the Diagnosis and Control of Bluetongue in Small Ruminants in Asia and the Epidemiology and Control of Bovine Ephemeral Fever in China
No full textLivestock Production/Industries,
David Martyn Lloyd-Jones 1899-1981 and twentieth-century evangelicalism.
No full textThe purpose of this thesis was to demonstrate the significance of the life and ministry of David Martyn Lloyd-Jones in post-war British evangelicalism and to show that, so far as Protestant churches in England and Wales were concerned, no history of the period can afford to ignore him. It is our contention that despite differences of opinion and self- marginalization Lloyd-Jones was and has remained a major force in evangelical thinking. In order to understand how this developed the thesis has been structured along thematic lines highlighting events, persons and questions. The study begins by setting the stage with a biographical chapter and goes on to examine the kind of impact that Lloyd-Jones's preaching had on Christians of all denominations. He believed preaching to be the greatest need of the day and the position of this thesis is that preaching was Lloyd-Jones's greatest contribution to twentieth- century Christianity. As a preacher he attracted one of London's largest congregations and in chapter three we look at the history and nature of Westminster Chapel comparing it with neighbouring ministries, and establishing the kind of people who went to hear him. Chapters four and five ascertain the factors which shaped Lloyd-Jones's views on the church and show how his Reformed evangelicalism led in a separatist as opposed to an ecumenical direction and finally, to a position which was neither Congregational nor Presbyterian. Our further argument is that while he favoured unity among believers his separatist ecclesiology only exacerbated the situation and left evangelicals more divided than before. Chapters six to eight evaluate Lloyd-Jones's background, the nature of his leadership and the extent of his influence - factors which either shaped or were the outcome of his ministry - and looks at the issues which these questions raise
Accounting for Intergenerational Income Persistence: Noncognitive Skills, Ability and Education
No full textWe analyse in detail the factors that lead to intergenerational persistence among sons, where this is measured as the association between childhood family income and later adult earnings. We seek to account for the level of income persistence in the 1970 BCS cohort and also to explore the decline in mobility in the UK between the 1958 NCDS cohort and the 1970 cohort. The mediating factors considered are cognitive skills, non-cognitive traits, educational attainment and labour market attachment. Changes in the relationships between these variables, parental income and earnings are able to explain over 80% of the rise in intergenerational persistence across the cohorts. Copyright 2007 The Author(s). Journal compilation Royal Economic Society 2007.
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Ancestral absence of electron transport chains in Patescibacteria and DPANN
No full text© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Beam, J. P., Becraft, E. D., Brown, J. M., Schulz, F., Jarett, J. K., Bezuidt, O., Poulton, N. J., Clark, K., Dunfield, P. F., Ravin, N. V., Spear, J. R., Hedlund, B. P., Kormas, K. A., Sievert, S. M., Elshahed, M. S., Barton, H. A., Stott, M. B., Eisen, J. A., Moser, D. P., Onstott, T. C., Woyke, T., & Stepanauskas, R. Ancestral absence of electron transport chains in Patescibacteria and DPANN. Frontiers in Microbiology, 11, (2020): 1848, doi:10.3389/fmicb.2020.01848.Recent discoveries suggest that the candidate superphyla Patescibacteria and DPANN constitute a large fraction of the phylogenetic diversity of Bacteria and Archaea. Their small genomes and limited coding potential have been hypothesized to be ancestral adaptations to obligate symbiotic lifestyles. To test this hypothesis, we performed cell–cell association, genomic, and phylogenetic analyses on 4,829 individual cells of Bacteria and Archaea from 46 globally distributed surface and subsurface field samples. This confirmed the ubiquity and abundance of Patescibacteria and DPANN in subsurface environments, the small size of their genomes and cells, and the divergence of their gene content from other Bacteria and Archaea. Our analyses suggest that most Patescibacteria and DPANN in the studied subsurface environments do not form specific physical associations with other microorganisms. These data also suggest that their unusual genomic features and prevalent auxotrophies may be a result of ancestral, minimal cellular energy transduction mechanisms that lack respiration, thus relying solely on fermentation for energy conservation.This work was funded by the USA National Science Foundation grants 1441717, 1826734, and 1335810 (to RS); and 1460861 (REU site at Bigelow Laboratory for Ocean Sciences). RS was also supported by the Simons Foundation grant 510023. TW, FS, and JJ were funded by the U.S. Department of Energy Joint Genome Institute, a DOE Office of Science User Facility supported under Contract No. DE-AC02-05CH11231. NR group was funded by the Russian Science Foundation (grant 19-14-00245). SS was funded by USA National Science Foundation grants OCE-0452333 and OCE-1136727. BH was funded by NASA Exobiology grant 80NSSC17K0548
Polymer-based treatments to control runoff, leachate and erosion from engineered slopes at Simfer Mine, Guinea, Africa
No full textIt is necessary to understand the erodibility and hydrological response of mine-site slope forming materials (SFMs), because of increasing awareness of the environmental impacts of mining. Steep engineered slopes in high intensity rainfall environments present a serious erosion risk. Temporary surface stabilisers, such as polyacrylamides (PAMs) and polyvinylacrylic latex (PVALs) are potentially cost effective erosion control solutions. In this study PAM and PVAL efficacy to reduce runoff, leachate and erosion was assessed at two application rates, with and without gypsum on SFMs from an iron ore mine in Guinea (West Africa). NSPASS (near-surface photogrammetry assessment of slope forming materials’ surface roughness) is a novel method that integrates digital image capture and GIS. It is shown to detect and quantify surface micro-relief changes of 2-3 mm, not visible to the naked eye.
As expected, soil and non-soil SFMs were significantly different in terms of their physical and chemical properties. Phase I of the study investigated the erodibility of ten SFMs, including soil, ore and waste-rock. The results indicate that the hydrological response to rainfall of most SFMs is to generate leachate. Weathered phyllite (PHY-WEA) is the most erodible SFM by both runoff and leachate. Multiple regression analysis demonstrated that magnetic susceptibility, mineralogy and dry aggregate distribution; parameters not commonly assessed in erosion studies, are important in explaining SFM erodibility and hydrological response.
Phase II evaluated critically the effectiveness of three commercially available polymer solutions (two PAMs and one PVAL) at reducing runoff, leachate and erosion from four of the most erodible SFMs identified in Phase I. The results indicate that some PAM and PVAL treatments significantly reduce runoff, leachate and erosion. Polymer efficacy is highly dependent on the physical and chemical properties of the SFM, as well as the mechanism of polymer to SFM adsorption. Increasing the application rate of select treatments lowered leachate volumes, runoff and leachate total sediment loads. Contrary to previous studies, gypsum amendments did not significantly improve polymer efficiency.
This research has added to our understanding of the erodibility and hydrological response of soil and non-soil SFMs. This is the first study to evaluate critically the efficacy of PVALs in controlling erosion from mine-site SFMs. Future studies should continue to optimise NSPASS performance in monitoring changes in surface micro-relief
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