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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.
11

Simulation of human skin pigmentation disorders / Simulação de transtornos de pigmentação da pele humana

Barros, Renan Sales January 2013 (has links)
Nosso trabalho apresenta um modelo de simulação de transtornos de pigmentação humana. Nosso modelo é formado por um conjunto de equações diferenciais que definem um sistema reação-difusão. Nosso sistema simula algumas características do sistema pigmentar humano. Alterações nesse sistema podem levar a desequilíbrios na distribuição de melanina na pele resultando em artefatos conhecidos como lesões de pigmentação. Nosso modelo tem como objetivo reproduzir essas alterações e assim sintetizar lesões de pigmentação humanas. Nosso sistema reação-difusão foi elaborado tomando como base dados biológicos a respeito da pele humana, do sistema pigmentar e do ciclo de vida dos melanócitos, que são as principais células envolvidas nesse tipo de transtorno. A simulação desse tipo de transtorno apresenta diversas aplicações em dermatologia como, por exemplo, suporte para o treinamento de dermatologistas e auxílio no diagnóstico de transtornos de pigmentação. No entanto, nosso trabalho se concentra em aplicações relacionadas com computação gráfica. Assim, nós também apresentamos um método para transferir os resultados do nosso modelo de simulação para texturas e imagens de pele humana. Nesse contexto, o nosso modelo contribui para a geração de texturas de pele mais realistas e consequentemente para a geração de modelos de serem humanos mais realistas. Além disso, nós também comparamos os resultados da nossa simulação com lesões de pigmentações reais objetivando avaliar a qualidade das lesões geradas pelo nosso modelo. Para realizar essa comparação nós extraímos métricas das lesões sintetizadas e das lesões reais e comparamos os valores dessas métricas. Com base nessa comparação, nós observamos que as lesões sintetizadas apresentam as mesmas características das lesões reais. Ainda, para efeito de comparações visuais, nós também apresentamos imagens de lesões reais lado a lado com imagens sintetizadas e podemos observar que o método utilizado para produzir imagens de lesões a partir do resultado do nosso modelo de simulação produz resultados que são indistinguíveis das imagens reais. / Our work presents a simulation model of human pigmentation disorders. Our model is formed by a set of differential equations that defines a reaction-diffusion system. Our system simulates some features of the human pigmentary system. Changes in this system can lead to imbalances in the distribution of melanin in the skin resulting in artifacts known as pigmented lesions. Our model aims to reproduce these changes and consequently synthesize human pigmented lesions. Our reaction-diffusion system was developed based on biological data regarding human skin, pigmentary system and melanocytes life cycle. The melanocytes are the main cells involved in this type of human skin disorders. The simulation of such disorders has many applications in dermatology, for example, to assist dermatologists in diagnosis and training related to pigmentation disorders. However, our study focuses on applications related to computer graphics. Thus, we also present a method to transfer the results of our simulation model for textures and images of human skin. In this context, our model contributes to the generation of more realistic skin textures and consequently for the generation of more realistic human models. Moreover, we also compared the results of our simulation with real pigmented lesions to evaluate the quality of the lesions generated by our model. To perform this comparison we measured some features of real and synthesized pigmented lesions and we compared the results of these measurements. Based on this comparison, we observed that synthesized lesions exhibit the same characteristics of real lesions. Still, for the purpose of visual comparisons, we also present images of real lesions along with images of synthesized lesions. In this visual comparison, we can note that the method used to produce lesions images from the results of our simulation generates images that are indistinguishable from real images.
12

Simulation of human skin pigmentation disorders / Simulação de transtornos de pigmentação da pele humana

Barros, Renan Sales January 2013 (has links)
Nosso trabalho apresenta um modelo de simulação de transtornos de pigmentação humana. Nosso modelo é formado por um conjunto de equações diferenciais que definem um sistema reação-difusão. Nosso sistema simula algumas características do sistema pigmentar humano. Alterações nesse sistema podem levar a desequilíbrios na distribuição de melanina na pele resultando em artefatos conhecidos como lesões de pigmentação. Nosso modelo tem como objetivo reproduzir essas alterações e assim sintetizar lesões de pigmentação humanas. Nosso sistema reação-difusão foi elaborado tomando como base dados biológicos a respeito da pele humana, do sistema pigmentar e do ciclo de vida dos melanócitos, que são as principais células envolvidas nesse tipo de transtorno. A simulação desse tipo de transtorno apresenta diversas aplicações em dermatologia como, por exemplo, suporte para o treinamento de dermatologistas e auxílio no diagnóstico de transtornos de pigmentação. No entanto, nosso trabalho se concentra em aplicações relacionadas com computação gráfica. Assim, nós também apresentamos um método para transferir os resultados do nosso modelo de simulação para texturas e imagens de pele humana. Nesse contexto, o nosso modelo contribui para a geração de texturas de pele mais realistas e consequentemente para a geração de modelos de serem humanos mais realistas. Além disso, nós também comparamos os resultados da nossa simulação com lesões de pigmentações reais objetivando avaliar a qualidade das lesões geradas pelo nosso modelo. Para realizar essa comparação nós extraímos métricas das lesões sintetizadas e das lesões reais e comparamos os valores dessas métricas. Com base nessa comparação, nós observamos que as lesões sintetizadas apresentam as mesmas características das lesões reais. Ainda, para efeito de comparações visuais, nós também apresentamos imagens de lesões reais lado a lado com imagens sintetizadas e podemos observar que o método utilizado para produzir imagens de lesões a partir do resultado do nosso modelo de simulação produz resultados que são indistinguíveis das imagens reais. / Our work presents a simulation model of human pigmentation disorders. Our model is formed by a set of differential equations that defines a reaction-diffusion system. Our system simulates some features of the human pigmentary system. Changes in this system can lead to imbalances in the distribution of melanin in the skin resulting in artifacts known as pigmented lesions. Our model aims to reproduce these changes and consequently synthesize human pigmented lesions. Our reaction-diffusion system was developed based on biological data regarding human skin, pigmentary system and melanocytes life cycle. The melanocytes are the main cells involved in this type of human skin disorders. The simulation of such disorders has many applications in dermatology, for example, to assist dermatologists in diagnosis and training related to pigmentation disorders. However, our study focuses on applications related to computer graphics. Thus, we also present a method to transfer the results of our simulation model for textures and images of human skin. In this context, our model contributes to the generation of more realistic skin textures and consequently for the generation of more realistic human models. Moreover, we also compared the results of our simulation with real pigmented lesions to evaluate the quality of the lesions generated by our model. To perform this comparison we measured some features of real and synthesized pigmented lesions and we compared the results of these measurements. Based on this comparison, we observed that synthesized lesions exhibit the same characteristics of real lesions. Still, for the purpose of visual comparisons, we also present images of real lesions along with images of synthesized lesions. In this visual comparison, we can note that the method used to produce lesions images from the results of our simulation generates images that are indistinguishable from real images.
13

Simulation of human skin pigmentation disorders / Simulação de transtornos de pigmentação da pele humana

Barros, Renan Sales January 2013 (has links)
Nosso trabalho apresenta um modelo de simulação de transtornos de pigmentação humana. Nosso modelo é formado por um conjunto de equações diferenciais que definem um sistema reação-difusão. Nosso sistema simula algumas características do sistema pigmentar humano. Alterações nesse sistema podem levar a desequilíbrios na distribuição de melanina na pele resultando em artefatos conhecidos como lesões de pigmentação. Nosso modelo tem como objetivo reproduzir essas alterações e assim sintetizar lesões de pigmentação humanas. Nosso sistema reação-difusão foi elaborado tomando como base dados biológicos a respeito da pele humana, do sistema pigmentar e do ciclo de vida dos melanócitos, que são as principais células envolvidas nesse tipo de transtorno. A simulação desse tipo de transtorno apresenta diversas aplicações em dermatologia como, por exemplo, suporte para o treinamento de dermatologistas e auxílio no diagnóstico de transtornos de pigmentação. No entanto, nosso trabalho se concentra em aplicações relacionadas com computação gráfica. Assim, nós também apresentamos um método para transferir os resultados do nosso modelo de simulação para texturas e imagens de pele humana. Nesse contexto, o nosso modelo contribui para a geração de texturas de pele mais realistas e consequentemente para a geração de modelos de serem humanos mais realistas. Além disso, nós também comparamos os resultados da nossa simulação com lesões de pigmentações reais objetivando avaliar a qualidade das lesões geradas pelo nosso modelo. Para realizar essa comparação nós extraímos métricas das lesões sintetizadas e das lesões reais e comparamos os valores dessas métricas. Com base nessa comparação, nós observamos que as lesões sintetizadas apresentam as mesmas características das lesões reais. Ainda, para efeito de comparações visuais, nós também apresentamos imagens de lesões reais lado a lado com imagens sintetizadas e podemos observar que o método utilizado para produzir imagens de lesões a partir do resultado do nosso modelo de simulação produz resultados que são indistinguíveis das imagens reais. / Our work presents a simulation model of human pigmentation disorders. Our model is formed by a set of differential equations that defines a reaction-diffusion system. Our system simulates some features of the human pigmentary system. Changes in this system can lead to imbalances in the distribution of melanin in the skin resulting in artifacts known as pigmented lesions. Our model aims to reproduce these changes and consequently synthesize human pigmented lesions. Our reaction-diffusion system was developed based on biological data regarding human skin, pigmentary system and melanocytes life cycle. The melanocytes are the main cells involved in this type of human skin disorders. The simulation of such disorders has many applications in dermatology, for example, to assist dermatologists in diagnosis and training related to pigmentation disorders. However, our study focuses on applications related to computer graphics. Thus, we also present a method to transfer the results of our simulation model for textures and images of human skin. In this context, our model contributes to the generation of more realistic skin textures and consequently for the generation of more realistic human models. Moreover, we also compared the results of our simulation with real pigmented lesions to evaluate the quality of the lesions generated by our model. To perform this comparison we measured some features of real and synthesized pigmented lesions and we compared the results of these measurements. Based on this comparison, we observed that synthesized lesions exhibit the same characteristics of real lesions. Still, for the purpose of visual comparisons, we also present images of real lesions along with images of synthesized lesions. In this visual comparison, we can note that the method used to produce lesions images from the results of our simulation generates images that are indistinguishable from real images.
14

Avaliação da atividade da unidade epidermo-melânica e do dano dérmico no melasma

Brianezi, Gabrielli January 2016 (has links)
Orientador: Hélio Amante Miot / Resumo: A patogênese do melasma, especialmente o papel dos queratinócitos e fibroblastos no desenvolvimento e manutenção da doença não é bem compreendida. Alterações dérmicas como dano estrutural à zona de membrana basal, melanócitos em pêndulo, elastose solar, celularidade, proliferação vascular, além da expressão de mediadores inflamatórios, fatores de crescimento, expressão epitelial de melanocortina e receptores dos hormônios sexuais; sugerem interação entre a unidade epidermo-melânica e a derme na fisiopatologia do melasma. A pigmentação melânica da pele pode ser estimulada por diferentes vias de sinalização, sendo a radiação ultravioleta, citocinas dérmicas e inflamação epidérmica, os modelos mais usuais. Neste estudo, objetivamos comparar a morfologia nuclear e a textura da cromatina entre queratinócitos basais no melasma facial e pele adjacente, investigar a ativação das diferentes vias de estímulo à pigmentação, além do envolvimento da derme, com foco na zona de membrana basal e colágeno, no melasma facial. Para a sua execução, foram coletados pares de biópsias faciais (2mm) de mulheres adultas com melasma e de pele adjacente (<2 cm). Processaram-se para coloração de PAS e picrosirius red; imunofluorescência para p53, p38, IL- 1α, αMSH, MC1R e COX2; imunoistoquímica para Melan-Acontracorada com PAS; Microscopia Eletrônica de Transmissão, além de cultura primária de fibroblastos para real-timePCR array e marcação para SA-β-gal. Foram avaliados: núcleos de quer... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The melasma pathogenesis, specially the role of keratinocytes and fibroblast in the disease development and maintenance are not completely understood. Dermal alterations such as basal membrane structural damage, pendulous melanocytes, solar elastosis, cellularity, vascular proliferation, in addition to the expression of inflammatory mediators, grow factors, epithelial melanocortin and sexual hormones receptors, suggest there is an interaction between the epidermal melanin unit and dermis in melasma physiopathology. The melanin skin pigmentation can be stimulated by different signaling pathways. UVR, dermal cytokines and epidermal inflammation are the most common models. These study aims to compare the nuclear morphology and chromatin texture in basal keratinocytes between melasma and adjacent skin, to investigate the activation of different pigmentation signaling pathways, and the dermal involvement, focusing on basal membrane zone and collagen. Therefore, facial skin biopsies (2 mm) from women were taken from melasma and normal skin (<2 cm apart) and processed for PAS and picrosirius red; immunofluorescence for p53, p38, IL-1α, αMSH, MC1R and COX2, immunohistochemistry for Melan-A counterstaining with PAS, and transmission electronic microscopy. Furthermore, primary fibroblast culture for real-timePCRarray and SA-β-gal staining. The nuclei of basal keratinocytes were evaluated as nuclear morphometry and chromatin texture; the fluorescence intensity was quantified in the epid... (Complete abstract click electronic access below) / Doutor
15

Avaliação da atividade da unidade epidermo-melânica e do dano dérmico no melasma / Activity evaluation of epidermo-melanin unit and dermal damage in melasma

Brianezi, Gabrielli [UNESP] 26 January 2016 (has links)
Submitted by GABRIELLI BRIANEZI null (gabrielli.brianezi@hotmail.com) on 2016-02-26T15:36:13Z No. of bitstreams: 1 20160224 Tese Gabrielli Brianezi.pdf: 3073309 bytes, checksum: 8fd0793265926aa1a58aea12aad689a6 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-02-26T20:04:11Z (GMT) No. of bitstreams: 1 brianezi_g_dr_bot.pdf: 3073309 bytes, checksum: 8fd0793265926aa1a58aea12aad689a6 (MD5) / Made available in DSpace on 2016-02-26T20:04:11Z (GMT). No. of bitstreams: 1 brianezi_g_dr_bot.pdf: 3073309 bytes, checksum: 8fd0793265926aa1a58aea12aad689a6 (MD5) Previous issue date: 2016-01-26 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A patogênese do melasma, especialmente o papel dos queratinócitos e fibroblastos no desenvolvimento e manutenção da doença não é bem compreendida. Alterações dérmicas como dano estrutural à zona de membrana basal, melanócitos em pêndulo, elastose solar, celularidade, proliferação vascular, além da expressão de mediadores inflamatórios, fatores de crescimento, expressão epitelial de melanocortina e receptores dos hormônios sexuais; sugerem interação entre a unidade epidermo-melânica e a derme na fisiopatologia do melasma. A pigmentação melânica da pele pode ser estimulada por diferentes vias de sinalização, sendo a radiação ultravioleta, citocinas dérmicas e inflamação epidérmica, os modelos mais usuais. Neste estudo, objetivamos comparar a morfologia nuclear e a textura da cromatina entre queratinócitos basais no melasma facial e pele adjacente, investigar a ativação das diferentes vias de estímulo à pigmentação, além do envolvimento da derme, com foco na zona de membrana basal e colágeno, no melasma facial. Para a sua execução, foram coletados pares de biópsias faciais (2mm) de mulheres adultas com melasma e de pele adjacente (<2 cm). Processaram-se para coloração de PAS e picrosirius red; imunofluorescência para p53, p38, IL- 1α, αMSH, MC1R e COX2; imunoistoquímica para Melan-Acontracorada com PAS; Microscopia Eletrônica de Transmissão, além de cultura primária de fibroblastos para real-timePCR array e marcação para SA-β-gal. Foram avaliados: núcleos de queratinócitos da camada basal quanto à morfometria nuclear e textura da cromatina; quantificada a intensidade de fluorescência nos compartimentos da epiderme e derme; avaliadas organelas citoplasmáticas e zona de membrana basal; além do colágeno dérmico e densidade de melanócitos: totais e em pêndulo. Em relação à pele adjacente sem melasma: núcleos de queratinócitos basais da epiderme com melasma facial apresentaram índices morfométricos e textura da cromatina alterados; houve aumento da expressão epitelial de αMSH e MC1R, sem diferença quanto ao p53, p38, IL1α e COX2; houve maior número de organelas citoplasmáticas e melanossomas em estágios de maturação maiores nos queratinócitos e melanócitos; áreas danificadas na zona de membrana basal com presença de microvesículas adjacentes à membrana basal; maior número de melanócitos em pêndulo; colágeno dérmico desestruturado. Entre os fibroblastos, houve maior marcação para SA-β-gal e expressão alterada dos genes COL4A1, IL6, ESR2, DKK3, CCL2, WIF1, WNT3A, HGF, IL1B, MMPs 1-7-9 no melasma. As alterações encontradas nos queratinócitos, na derme e zona de membrana basal, sugerem que o fenótipo do melasma pode resultar de alterações em toda unidade epidermo-melânica, não somente de uma hipertrofia dos melanócitos, as vias inflamatórias da epiderme e dependentes de p53 não se mostraram proeminentes, além de ser identificado um possível papel do processo de reparo/dano da derme e da senescência de fibroblastos na patogênese da doença. / The melasma pathogenesis, specially the role of keratinocytes and fibroblast in the disease development and maintenance are not completely understood. Dermal alterations such as basal membrane structural damage, pendulous melanocytes, solar elastosis, cellularity, vascular proliferation, in addition to the expression of inflammatory mediators, grow factors, epithelial melanocortin and sexual hormones receptors, suggest there is an interaction between the epidermal melanin unit and dermis in melasma physiopathology. The melanin skin pigmentation can be stimulated by different signaling pathways. UVR, dermal cytokines and epidermal inflammation are the most common models. These study aims to compare the nuclear morphology and chromatin texture in basal keratinocytes between melasma and adjacent skin, to investigate the activation of different pigmentation signaling pathways, and the dermal involvement, focusing on basal membrane zone and collagen. Therefore, facial skin biopsies (2 mm) from women were taken from melasma and normal skin (<2 cm apart) and processed for PAS and picrosirius red; immunofluorescence for p53, p38, IL-1α, αMSH, MC1R and COX2, immunohistochemistry for Melan-A counterstaining with PAS, and transmission electronic microscopy. Furthermore, primary fibroblast culture for real-timePCRarray and SA-β-gal staining. The nuclei of basal keratinocytes were evaluated as nuclear morphometry and chromatin texture; the fluorescence intensity was quantified in the epidermis and dermis; cytoplasm organelles and basal membrane zone were evaluated; in addition to dermal collagen and melanocytes density: total and pendulous. Regarding adjacent healthy skin, the melasma skin showed alterations in morphometric index and chromatin texture; there was greater epithelial expression of αMSH and MC1R, but without difference for p53, p38, IL1α and COX2; cytoplasm organelles and melanossomas in higher maturity were in greater number in keratinocytes and melanocytes; there were commoner damaged areas in basal membrane zone, presence of microvesicules adjacent to basal membrane; and higher number of pendulous melanocyte; dermal collagen was less structured. There were greater SA-β-gal staining and altered expression of COL4A1, IL6, ESR2, DKK3, CCL2, WIF1, WNT3A, HGF, IL1B, MMPs 1-7-9 genes in melasma fibroblasts.The alterations presented in keratinocytes, dermis and basal membrane zone suggest the melasma phenotype can result from alteration in entire epidermal melanin unit, not just hypertrophic melanocytes, the epidermal inflammatory pathways and p53 dependents do not show prominence, in addition to the possible role of the repair/ damage process identified at dermis and fibroblast senescence in the melasma pathogenesis. / FAPESP: 12/09233-5 / FAPESP: 12/05004-1
16

Propagation and quality assessment for the introduction of Greyia Radlkoferi into commercialization

Nogemane, Noluyolo 02 1900 (has links)
Greyia radlkoferi is a South African indigenous tree, which has recently been discovered to be a source of extracts that have a potential in the development of cosmeceutical herbal products having the ability to treat hyperpigmentation disorders. For product development however, G. radlkoferi would need to be available in a commercial scale. Greyia radlkoferi grows naturally in the wild and is often available for cultivation as an ornamental plant. In order to establish this plant into cultivation, suitable propagation techniques must be established for rapid multiplication of trees and thus a sustainable leaf production. For consistent and improved leaf supply to the market, agronomic practices that will enhance leaf production were investigated in the current study. Furthermore, in order to meet market demand in terms of good quality extracts with guaranteed therapeutic efficiency, pre-harvest and post-harvest factors that affect the chemical composition of the extracts were investigated. Recently developed biotechnology techniques such as metabolomics using 1H-NMR and multivariate data analysis offered a platform to study the chemical variation of extracts. Therefore, the current study was aimed at understanding the requirements for propagation and optimum leaf production as well as conditions that favour optimum production of secondary metabolite of G. radlkoferi plant material (at pre and post-harvest) and thus assess its commercial viability. To understand the effects of temperature on seed germination of G. radlkoferi, seeds were exposed to five temperatures (10°C, 15°C, 20°C, 25°C and 30°C) in the incubators in the laboratory. Germination of G. radlkoferi by seeds was discovered to be temperature dependent. The optimum germination temperature of 81% was obtained at 25°C. In the case of vegetative propagation by stem cuttings, the effect of cutting position (basal or apical), exogenous rooting hormone (Seradix1, Seradix 2, 0.1% IBA, 0.3% IBA and 0.8% IBA) and cutting position were investigated in the glasshouse. The cutting position had a significant effect on rooting of G. radlkoferi cuttings with basal cuttings exhibiting 35% rooting as compared to 6% rooting attained for the apical cuttings. A clear trend in rooting response to application of rooting hormones was observed, with 0.1% Indole butyric acid (IBA) showing the highest rooting percentage of 63%. Considering the outcomes of the propagation studies as well as the limited material for vegetative propagation, seed propagation appears to be the most suitable technique for large-scale multiplication of G. radlkoferi. The effect of different pruning techniques as well as harvesting frequencies on fresh and dry weights of G. radlkoferi leaves were evaluated. Factors considered were four pruning treatments (‘pruned but not tipped’, ‘tipped but not pruned’, ‘not pruned nor tipped’ as well as ‘pruned and tipped’) and three harvesting periods (monthly, bimonthly and once–off). Bimonthly harvests highly increased leaf production compared to trees that were harvested monthly and once-off with higher leaf fresh weight yield of 238 g per tree or 2.38 tons/per hectare as well as dry weight yield of 83 g per tree or 0.830 tons/hectare. This outcomes of this study further suggested that a suitable pruning practice for G. radlkoferi would be to either ‘prune only’ or ‘cut back the main stem’ rather than a combination of the two treatments. The influence of seasons (summer, autumn, winter and spring) on the anti-tyrosinase activity and metabolomics profile of G. radlkoferi leaf extracts were investigated. Seasons significantly influenced the chemical composition and the efficacy of the plant extracts. Tyrosinase enzyme inhibition was investigated against monophenolase (tyrosine) with kojic acid as positive control. The highest tyrosinase inhibition concentration with IC50 (50% tyrosinase inhibition concentration) value of 30.3±1.8 μg/ml were obtained in winter harvested leaves compared to the other seasons. The lowest IC50 values were obtained in spring. Metabolomics analysis using orthogonal partial least square discriminant analysis (OPLS-DA) provided a clear class separation according to the harvest season. Extracts from winter harvested leaves contained sucrose, acetamide, alanine and a compound of the catechin group (gallocatechin-(4 alpha->8)-epigallocatechin) as revealed by 1H-NMR metabolomics with assistance of LC-MS. Since compounds of the catechin group are well-known tyrosinase inhibitors, the high tyrosinase activity exhibited in extracts of winter harvested G. radlkoferi leaves could be ascribed to the presence of gallocatechin-(4 alpha->8)-epigallocatechin. Based on the outcomes of the seasonal study, we suggest that in order to obtain extracts with high bioactivity, the best suitable time for harvesting leaf samples is in late autumn-early winter. Processing leaf material using three different drying methods (sun, oven and air drying) significantly influenced chemical composition and the efficacy of the plant extracts. Extracts prepared from air-dried leaf material showed the highest tyrosinase inhibition with IC50 value of 17.80 μg/ml compared to extracts of the other drying methods. Extracts of leaves processed with air drying preserved most metabolites during processing while extracts of sun-dried and oven-dried leaves clearly depleted some metabolites especially amino acids and some aromatic compounds. 1H-NMR metabolomics approach with the assistance of LC-MS data successfully determined a positive association of alanine, acetamide, sucrose and gallocatechin-(4 alpha->8)-epigallocatechin as the chemical constituents contributing to the variation in the air-dried leaves compared to the oven-dried leaves. A positive association of valine, alanine, leucine, isoleucine, gallocatechin-(4 alpha->8)-epigallocatechin and glucose contributed to the variation in air-dried group, compared to the sun-dried group. The highest tyrosinase inhibitory activity exhibited in air-dried samples compared to the other drying methods was associated with the presence of gallocatechin-(4 alpha->8)-epigallocatechin. Because air drying preserved most leaf metabolites compared to sun and oven drying, it was regarded as the most suitable method for processing G. radlkoferi leaf material. This study is the first scientific account that provides guidelines and recommendations to (1) establish G. radlkoferi as a cultivated plant for commercialization, (2) optimize leaf production for sustainable supply to the commercial markets and (3) optimize medicinal content of G. radlkoferi related to harvesting time and post-harvest processing (drying), for enhanced quality of extracts and its products / Agriculture, Animal Health and Human Ecology / Ph. D. (Agriculture)
17

A selection of legal issues relating to persons living with albinism

Mswela, Mphoeng Maureen 10 1900 (has links)
Despite the fact that albinism affects several South Africans, it is a condition that remains deeply misunderstood. Albinism is steeped in myth and false notions, and is perceived by many as a curse and contamination. For years, persons living with albinism have been treated with doubt and suspicion. Also in schools and in the wider community, children with albinism are subjected to violence and ridicule. In certain areas on the African continent, including Southern Africa, persons living with albinism are killed for the trade in body parts for use as sacramental medicines, or sexually assaulted as a result of the belief that raping them may offer a cure for HIV/AIDS. All of this highlights the extreme vulnerability of persons living with albinism, not to mention the many violations of their fundamental rights that follow from the manner in which they are treated. Within the social context that frames the experience of persons living with albinism, the primary purpose of this study is to highlight some of the pertinent challenges faced by persons living with albinism in South Africa which compromise the full enjoyment of their fundamental rights as enshrined in the South African Constitution. The thesis makes a number of practical recommendations that will assist in promoting the legal position of this vulnerable group, while also contributing to a better understanding of albinism in general which will ultimately change negative perceptions and debunk the myths surrounding the condition. / Jurisprudence / LL. D.

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