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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Masks

Nicholas, Jeffrey Francis 22 April 2016 (has links)
No description available.
102

Hra, hravost a hračka ve výtvarném umění / Play and toy in contemporary art

Nováková, Kateřina January 2010 (has links)
My thesis concentrates on the game, the playfulness and the toy. At first, I was searching for where these topics were most common and how they effected our lives generally. I presented some of the definitions. Then I worked more with these definitions and I put them into a connection with the art and the padegogy. Later I made a separated point of the role of the game, the playfulness and the toy in the visual art. I introduced some artist, who have been using the topics of mainly the game and the playfulness in their art work. The toy was presented more like the theme of the art works. The final part concentrates on the visual art project, which is prepared for children at age eight to ten years. One of the range was introduced deeply. n this range present individual lessons, one of them is showed in detail. This lesson is named The painting by the soap bubbles and I had been taught it at The basic art school Na Proseku. After this lesson I wrote reflection of it. Whole thesis is ilustrated by the pictures. In the conclusion I try to summarize knowledge I reached.
103

Recombination dynamics of optically generated small polarons and self-trapped excitons in lithium niobate

Messerschmidt, Simon 02 July 2019 (has links)
Quasi-particles formed in lithium niobate after pulse exposure were investigated by transient absorption and photoluminescence spectroscopy as well as numerical simulations. This includes the formation process, the transport through the crystal, interim pinning on defects during the relaxation process, and the final recombination with deep centers. It was shown that the charge-transport through the crystal can be described by a hopping transport including different types of hops between regular or defective lattice sites, i.e., the transport includes a mixture of free and bound small polarons. Furthermore, the different types of hops connected with varying activation energies and their distribution are responsible for an altered temporal decay curve when changing the crystal composition or temperature. Additionally, it was shown that the hitherto accepted recombination model is insufficient to describe all transient absorption and luminescence effects in lithium niobate under certain experimental conditions, i.e., long-living absorption dynamics in the blue/UV spectral range do not follow the typical polaron dynamics and cannot be described under the assumption of charge compensation. However, similar decay characteristics between self-trapped excitons known from photoluminescence spectroscopy and the unexpected behavior of the transient absorption were found leading to a revised model. This includes, besides the known polaron relaxation and recombination branch, a significant role of self-trapped excitons and their pinning on defects (pinned STEs). Since the consideration of further absorption centers in the relaxation path after pulse exposure might result in misinterpretations of previously determined polaron absorption cross-sections and shapes, the necessity to perform a review became apparent. Therefore, a supercontinuum pump-probe experiment was designed and all measurements applied under the same experimental conditions (temperature, polarization) so that one can extract the absorption amplitudes of the single quasi-particles in a spectral range of 0.7-3.0eV. The detailed knowledge might be used to deconvolve the absorption spectra and transform them to number densities of the involved centers which enables one to obtain an easier insight into recombination and decay dynamics of small polarons and self-trapped excitons. As the hopping transport of quasi-particles and the concept of pinned STEs might be fundamental processes, a thorough understanding opens up the possibility of their exploitation in various materials. In particular, results presented herein are not only limited to lithium niobate and its applications; an extension to a wide range of further strongly polar crystals in both their microscopic processes and their use in industry can be considered.
104

Effects of iron and omega-3 supplementation on the immune system of iron deficient children in South Africa : a randomised controlled trial / Linda Malan

Malan, Linda January 2014 (has links)
Background Iron deficiency (ID) is the world‟s most prevalent micronutrient deficiency and predominantly affects developing countries, also South Africa. In areas with low fish consumption and high n-6 PUFA vegetable oil intake, there is a risk for having inadequate n-3 PUFA status. Both iron and n-3 PUFA play important roles in the immune response, and supplementation is a strategy to alleviate deficiencies. However, little is known about potential interactive effects between concurrent iron and n-3 PUFA supplementation on the immune system. This is also important in the context that iron supplementation may be unsafe and may increase morbidity and mortality. Aim The overall aim of this thesis was to assess the effects of iron and docosahexaenoic (DHA)/eicosapentaenoic acid (EPA) supplementation, alone and in combination, on the immune system of ID children. More specifically, these effects were investigated on the occurrence and duration of illness and school-absenteeism due to illness, peripheral blood mononuclear cell (PBMC), red blood cell (RBC) and plasma total phospholipid fatty acid composition, iron status, fatty acid-derived immune modulators and targeted PBMC gene expression. Furthermore, association of PBMC, RBC and plasma total phospholipid fatty acid composition with allergic disease, were also examined. Design In a 2-by-2 factorial, randomised, double-blind, placebo-controlled trial, South African children (n = 321, aged 6–11 y) were randomly assigned to receive oral supplements of either 1) iron (50 mg as ferrous sulphate) plus placebo; 2) DHA/EPA (420/80 mg) plus placebo; 3) iron plus DHA/EPA (420/80 mg); or 4) placebo plus placebo for 8.5 mo, four times per week. Absenteeism and illness symptoms were recorded and biochemical parameters for compliance as well as parameters fundamental to immune function were assessed at baseline and endpoint. Furthermore, in a cross-sectional design, associations of allergic disease with baseline fatty acid composition of PBMC, RBC and plasma were examined. Results The combination of iron and DHA/EPA significantly attenuated respiratory illness caused by iron supplementation. DHA/EPA supplementation alone improved respiratory symptoms at school, but increased headache-related absenteeism. DHA/EPA and iron supplementation individually tended to increase and decrease anti-inflammatory DHA and EPA-derived mediators, respectively. Furthermore the anti-inflammatory DHA-derived immune mediator, 17HDHA was higher in the DHA/EPA plus placebo and iron plus DHA/EPA groups than in the iron plus placebo group. Also, the pro-inflammatory arachidonic acid (AA)-derived modulators (5- and 15-hydroxyeicosapentaenoic acid) were significantly lower in the iron plus DHA/EPA group compared to the placebo plus placebo groups. In the study population, 27.2% of the children had allergic disease and AA in PBMC phospholipids was significantly lower in the allergic children than in the non-allergic children. In RBC phospholipids dihomo-gamma-linolenic acid (DGLA) and the ratio of DGLA: linoleic acid (LA) correlated negatively and the n-6:n-3 PUFA ratio positively with total immunoglobulin E (tIgE). Furthermore, trans-C18:1n-9, tended to be higher in the allergic group. Conclusion DHA/EPA prevented respiratory illness caused by iron supplementation and although DHA/EPA on its own reduced respiratory morbidity when the children were present at school, surprisingly it increased the likelihood of being absent with headache and fever. The biochemical findings compliment the clinical results and support previous observations about DHA/EPA supplementation to reduce inflammation, but add to the current knowledge base that a relatively high oral dose of non-haem iron modulates circulating lipid-derived immune modulators and related gene expression. Furthermore, when supplementing with iron and DHA/EPA combined, in this ID population with low fish intake, the anti-inflammatory effect of DHA/EPA is maintained concurrently with attenuation of respiratory morbidity. This finding support the notion that excess iron (probably as non-transferrin bound iron) becomes available for pathogens and is probably why we found that iron increased respiratory infectious morbidity. The improved clinical outcome with combined supplementation seems to be related to increased lipid-mediator synthesis gene expression and the availability of DHA/EPA, leading to a more pro-resolving profile and enhanced immune competence. Overall these results give better insight into immune function and infectious morbidity in relation to n-3 PUFA and iron status and treatment, as well as the possible association of fatty acid status with allergic disease in young South-African school children. / PhD (Nutrition), North-West University, Potchefstroom Campus, 2015
105

Effects of iron and omega-3 supplementation on the immune system of iron deficient children in South Africa : a randomised controlled trial / Linda Malan

Malan, Linda January 2014 (has links)
Background Iron deficiency (ID) is the world‟s most prevalent micronutrient deficiency and predominantly affects developing countries, also South Africa. In areas with low fish consumption and high n-6 PUFA vegetable oil intake, there is a risk for having inadequate n-3 PUFA status. Both iron and n-3 PUFA play important roles in the immune response, and supplementation is a strategy to alleviate deficiencies. However, little is known about potential interactive effects between concurrent iron and n-3 PUFA supplementation on the immune system. This is also important in the context that iron supplementation may be unsafe and may increase morbidity and mortality. Aim The overall aim of this thesis was to assess the effects of iron and docosahexaenoic (DHA)/eicosapentaenoic acid (EPA) supplementation, alone and in combination, on the immune system of ID children. More specifically, these effects were investigated on the occurrence and duration of illness and school-absenteeism due to illness, peripheral blood mononuclear cell (PBMC), red blood cell (RBC) and plasma total phospholipid fatty acid composition, iron status, fatty acid-derived immune modulators and targeted PBMC gene expression. Furthermore, association of PBMC, RBC and plasma total phospholipid fatty acid composition with allergic disease, were also examined. Design In a 2-by-2 factorial, randomised, double-blind, placebo-controlled trial, South African children (n = 321, aged 6–11 y) were randomly assigned to receive oral supplements of either 1) iron (50 mg as ferrous sulphate) plus placebo; 2) DHA/EPA (420/80 mg) plus placebo; 3) iron plus DHA/EPA (420/80 mg); or 4) placebo plus placebo for 8.5 mo, four times per week. Absenteeism and illness symptoms were recorded and biochemical parameters for compliance as well as parameters fundamental to immune function were assessed at baseline and endpoint. Furthermore, in a cross-sectional design, associations of allergic disease with baseline fatty acid composition of PBMC, RBC and plasma were examined. Results The combination of iron and DHA/EPA significantly attenuated respiratory illness caused by iron supplementation. DHA/EPA supplementation alone improved respiratory symptoms at school, but increased headache-related absenteeism. DHA/EPA and iron supplementation individually tended to increase and decrease anti-inflammatory DHA and EPA-derived mediators, respectively. Furthermore the anti-inflammatory DHA-derived immune mediator, 17HDHA was higher in the DHA/EPA plus placebo and iron plus DHA/EPA groups than in the iron plus placebo group. Also, the pro-inflammatory arachidonic acid (AA)-derived modulators (5- and 15-hydroxyeicosapentaenoic acid) were significantly lower in the iron plus DHA/EPA group compared to the placebo plus placebo groups. In the study population, 27.2% of the children had allergic disease and AA in PBMC phospholipids was significantly lower in the allergic children than in the non-allergic children. In RBC phospholipids dihomo-gamma-linolenic acid (DGLA) and the ratio of DGLA: linoleic acid (LA) correlated negatively and the n-6:n-3 PUFA ratio positively with total immunoglobulin E (tIgE). Furthermore, trans-C18:1n-9, tended to be higher in the allergic group. Conclusion DHA/EPA prevented respiratory illness caused by iron supplementation and although DHA/EPA on its own reduced respiratory morbidity when the children were present at school, surprisingly it increased the likelihood of being absent with headache and fever. The biochemical findings compliment the clinical results and support previous observations about DHA/EPA supplementation to reduce inflammation, but add to the current knowledge base that a relatively high oral dose of non-haem iron modulates circulating lipid-derived immune modulators and related gene expression. Furthermore, when supplementing with iron and DHA/EPA combined, in this ID population with low fish intake, the anti-inflammatory effect of DHA/EPA is maintained concurrently with attenuation of respiratory morbidity. This finding support the notion that excess iron (probably as non-transferrin bound iron) becomes available for pathogens and is probably why we found that iron increased respiratory infectious morbidity. The improved clinical outcome with combined supplementation seems to be related to increased lipid-mediator synthesis gene expression and the availability of DHA/EPA, leading to a more pro-resolving profile and enhanced immune competence. Overall these results give better insight into immune function and infectious morbidity in relation to n-3 PUFA and iron status and treatment, as well as the possible association of fatty acid status with allergic disease in young South-African school children. / PhD (Nutrition), North-West University, Potchefstroom Campus, 2015
106

Mitchell's mandalas : mapping David Mitchell's textual universe

Harris-Birtill, Rosemary January 2017 (has links)
This study uses the Tibetan mandala, a Buddhist meditation aid and sacred artform, as a secular critical model by which to analyse the complete fictions of author David Mitchell. Discussing his novels, short stories and libretti, this study maps the author's fictions as an interconnected world-system whose re-evaluation of secular belief in galvanising compassionate ethical action is revealed by a critical comparison with the mandala's methods of world-building. Using the mandala as an interpretive tool to critique the author's Buddhist influences, this thesis reads the mandala as a metaphysical map, a fitting medium for mapping the author's ethical worldview. The introduction evaluates critical structures already suggested to describe the author's worlds, and introduces the mandala as an alternative which more fully addresses Mitchell's fictional terrain. Chapter I investigates the mandala's cartographic properties, mapping Mitchell's short stories as integral islandic narratives within his fictional world which, combined, re-evaluate the role of secular belief in galvanising positive ethical action. Chapter II discusses the Tibetan sand mandala in diaspora as a form of performance when created for unfamiliar audiences, reading its cross-cultural deployment in parallel with the regenerative approaches to tragedy in the author's libretti Wake and Sunken Garden. Chapter III identifies Mitchell's use of reincarnation as a form of non-linear temporality that advocates future-facing ethical action in the face of humanitarian crises, reading the reincarnated Marinus as a form of secular bodhisattva. Chapter IV deconstructs the mandala to address its theoretical limitations, identifying the panopticon as its sinister counterpart, and analysing its effects in number9dream. Chapter V shifts this study's use of the mandala from interpretive tool to emerging category, identifying the transferrable traits that form the emerging category of mandalic literature within other post-secular contemporary fictions, discussing works by Michael Ondaatje, Ali Smith, Yann Martel, Will Self, and Margaret Atwood.
107

Multivalence, liminality, and the theological imagination : contextualising the image of fire for contemporary Christian practice

Dyer, Rebekah Mary January 2018 (has links)
This thesis contends that the image of fire is a multivalent and theologically valuable image for application in British Christian communities. My research offers an original contribution by contextualising the image of fire for Christian practice in Britain, and combining critical observation of several contemporary fire rites with theological analysis. In addition, I conduct original case studies of three Scottish fire rituals: the Stonehaven Fireball Ceremony, the Beltane Fire Festival, and Up-Helly-Aa in Lerwick, Shetland. The potential contribution of fire imagery to Christian practice has been overlooked by modern theological scholarship, social anthropologists, and Christian practitioners. Since the multivalence of the image has not been fully recognised, fire imagery has often been reduced to a binary of ‘positive' and ‘negative' associations. Through my study of non-faith fire rituals and existing Christian fire practices, I explore the interplay between multivalence, multiplicity, and liminality in fire imagery. I demonstrate that deeper theological engagement with the image of fire can enhance participation, transformation, and reflection in transitional ritual experience. I argue that engaging with the multivalence of the image of fire could allow faith communities to move beyond dominant interpretive frameworks and apply the image within their own specific context. First, I orientate the discussion by examining the multivalence of biblical fire imagery and establishing the character of fire within the British social imagination. Second, I use critical observation of community fire practices in non-faith contexts to build a new contextual framework for the analysis of fire imagery. Finally, I apply my findings to a contextual analysis of existing Christian fire practices in Britain. Throughout, I argue that sensory and imaginative interaction with the image of fire provides a way to communicate and interact with theological ideas; experience personal and communal change; and mediate experience of the sacred.

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