Thesis (M.Med.Sc.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 44-57). Also available in print.

Thesis (M. Sc.)(Biochemistry)--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.

In this sector analysis I report on my investigation of the International Smallholder Tea Sector and its incorporation into global policy spheres. “Globally, tea smallholder sector covers 70% of the plantation area and produces 60% of the global tea production volume (UNFAO, 2017) Therefore, I argue that smallholder farmers should play a greater role in creating value through representation in dynamic policy discussions, such as the UNFAO Intergovernmental Group on Tea. I address how small landholders are economically developing and overall industry strategy. I suggest governance structures in order to address challenges and opportunities in future development and specifically look at the dynamic position of global policy making and industry trends, as they pertain to the potential for sustainability and long term-success of this important industry. My regional emphasis on South Asia provides a setting to focus on shared global trends as they pertain to social, cultural, biological production atmospheres.

Leaching is one of the major processes occurring when organic litter is decomposed and is often completed within a few days when litter enters aquatic environments. It is important that leaching is addressed when studying microbial and invertebrate decomposition rates in order to avoid overestimations. The traditional litter bag method that has been used to measure decomposition rates in both terrestrial and aquatic environments has in recent years been challenged by the new and widely adopted tea bag index (TBI). Both methods, however, fail to bring a standardized methodology for separating and recognizing weight losses of litter due to leaching and biotic decomposition. Through a field experiment in two streams with different water discharge, this study has focused on exploring the leaching phase and post-leaching phase of the tea products used in TBI. The results unveiled that 20% of rooibos tea’s and 44% of green tea’s initial weight was lost to leaching within three days (72 hours) of the experiment. After the 72nd hour, both teas remained in a stabilized phase until the end of the experiment (120 hours). Water discharge had no significant effect on neither of the tea-weights during or after the leaching phase. This study recommends that weight loss through the leaching phase are taken into account in future studies and advocate the development of an updated TBI protocol where leaching losses are recognized. If not, overestimations of active decomposition rates will be made and may result in compromised conclusions. / Urlakning är en av de viktigaste processerna som uppstår vid nedbrytning av organiskt material och är ofta slutfört inom några dagar när materialet befinner sig i vattenmiljöer. Det är viktigt att den urlakade massan beräknas när studier fokuserade på nedbrytningshastigeter av mikrober och evertebrater genomförs, detta för att undvika en överestimering av den biotiska aktiviteten. Den traditionella metoden, där torkade växtdelar i påsar, har använts för att mäta nedbrytningshastigheter i både mark- och vattenmiljöer har under de senaste åren utmanats av det nya och allmänt accepterade tepåse-indexet (TBI). Båda metoderna misslyckas dock med att implementera en standardiserad metodik för att separera och uppskatta materialets viktförluster genom urlakning och biotisk nedbrytning. Genom ett fältexperiment i två vattendrag med olika vattenföring har denna studie fokuserat på att undersöka urlakningsfasen och den stabiliserade perioden efter urlakningen hos teprodukterna som används i TBI. Resultaten avslöjade att 20% av rooibos tes och 44% av grönt tes ursprungliga vikt förloras genom urlakning inom tre dagar (72 timmar) av experimentet. Efter den 72:a timmen förblev båda teerna i en stabiliserad fas till slutet av experimentet (120 timmar). Vattenflöde hade ingen signifikant effekt på någon av tetypernas vikter, varken för perioden under eller efter urlakningsfasen. Denna studie rekommenderar att viktminskning genom urlakningsfasen beaktas i framtida studier och förespråkar utvecklingen av ett uppdaterat TBI-protokoll för att inkludera urlakningens påverkan. Om inte, kommer överskattningar av aktiva nedbrytningshastigheter att göras och kan leda till äventyrade slutsatser.

中國茶文化源遠流長，茶作為一種日常飲品，與咖啡、可可並稱為世界三大無酒精飲料。近年來，隨著人們生活水平的日益提高，茶葉的保健功效越來越受到社會的重視。據各文獻史料記載，我國飲用茶葉已有千年曆史，記載有關茶葉的文獻古籍繁多。而一直以來，茶葉與“健康”一詞密不可分，古人經過歸納前人的記述總結出了茶葉的二十四功效，如清熱、消食、醒酒、去疾等，並對茶有著極高的評價，然而很少人注意到通過飲茶所達到的有利功效需要建立在適度飲茶，科學飲茶的前提下，盲目品飲只會起到相反效果。與此同時，隨著醫學經驗、藥學知識的日益豐富，不當飲茶所帶來的一些副作用同樣也引起了古代醫學家與茶人的重視，人們開始不僅只是單純的追求茶葉的口感，更多的是開始關注飲茶對身體的影響及飲茶時的身心體驗，通過自己多年的親身感悟，長期與他人的經驗分享，總結歸納出了飲茶的利弊，教導後人飲茶需有度，因人而飲。 本文擬在分析我國古代文獻中飲茶不當導致的疾病，尋找飲用單一味茶葉對人體所產生的不良反應，其中不包括複方茶及非茶之“茶”，通過歸納、整理，探究古代不當飲茶所造成的對人體的危害疾病，提出適度飲茶，健康飲茶，科學飲茶的觀念，為今後的茶學及醫學研究不當飲茶致病因素提供古代文獻線索依據。 關鍵字：過度飲茶，過派飲茶，飲茶致病

Made available in DSpace on 2014-06-11T19:24:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-11-23Bitstream added on 2014-06-13T20:51:26Z : No. of bitstreams: 1 fonseca_bm_me_sjc.pdf: 775997 bytes, checksum: e77eb2f75ac56e60c212e110b913bb06 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste estudo foi avaliar a interface adesiva de amostras de dentina bovina / adesivo e resina variando as estratégias adesivas e o tempo de armazenamento. Foram selecionados 80 incisivos bovinos, limpos e seccionados 2,0 mm além da junção amelocementária, desgaste da superfície vestibular do esmalte, com exposição de uma área plana de dentina, a qual foi submetida a diferentes protocolos adesivos. Aleatoriamente, as amostras foram divididas em 4 grupos (n= 20), submetidos às estratégias adesivas: SB – controle: sistema adesivo Adper Single Bond 2 aplicado segundo instruções do fabricante; CLX – clorexidina: aplicação de solução de digluconato de clorexidina 0,2% previamente a aplicação do sistema adesivo semelhante ao SB; EGCG – EGCG10: aplicação da solução em gel de EGCG 10μM – principal componente ativo do chá verde – por 30 s previamente a aplicação do sistema adesivo semelhante ao SB; e CV – solução aquosa de chá verde: aplicação do chá verde – preparado após infusão da erva acondicionada em sachê – previamente a aplicação do sistema adesivo semelhante ao SB. Em todos os grupos foi aplicada resina composta (RC) Amelogen Plus com o auxílio de matriz de silicone, com fotopolimerização por 20 s cada incremento. Posteriormente, os grupos foram redivididos em dois subgrupos (n= 10) de acordo com o tempo de armazenamento em água destilada por 24 h e 6 meses, a 37ºC em estufa bacteriológica. Em seguida, todos os corpos-de-prova foram seccionados no sentido mésio-distal e cérvico-incisal em cortes paralelos de espessura aproximada de 0,8 mm2 em cortadeira Labcut (Extec Technologies – EUA) com refrigeração em baixa velocidade. Desta forma, foram obtidos em média 9 palitos por dente, sendo cada... / The aim of this study was evaluate the adhesive interface of bovine dentin samples / adhesive and resin varying adhesive strategies and time of storage. Eighty bovine incisors were selected, cleaned and sectioned 2.0 mm beyond the cementoenamel junction; the labial surface of the enamel was worn to obtain a flat area of exposed dentin. The dentin was subjected to different adhesives protocols. Samples were randomly divided into 4 groups (n = 20), according to the adhesive strategies: SB - control: Adper Single Bond 2 (SB) system was applied according to manufacturer's instructions; CHX - chlorhexidine: application of 0.2% chlorhexidine gluconate solution prior to adhesive system similar to SB; EGCG - EGCG10: application 10 μM EGCG gel - the main active component of green tea - for 30 s prior to application of the adhesive system similar to SB; and GT - aqueous green tea: application of green tea - prepared after infusion of the herb sachet - prior to application of the adhesive system similar to SB. The composite resin Amelogen Plus was applied in all groups with aid of silicone matrix, and lightcured for 20 s. Subsequently, groups were re-divided into two subgroups (n = 10) in accordance with the time of storage in distilled water, for 24h or 6 months at 37°. Specimens were sectioned to obtain parallel cuts and beams of approximately 0.8 mm2. Cut procedure was performed in Labcut cutting machine (Extec Technologies - USA) at low speed with cooling. Nine beams per tooth were obtained. Each beam was attached with cyanoacrylate glue to a device prepared for submission to the microtensile test, using a universal testing machine (DL-1000, EMIC, Pinhais-PR-Brazil) with 10 kgf load and speed of... (Complete abstract click electronic access below)

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>Magister Scientiae - MSc / The aim of this study was to investigate the presence of Salmonella in the tea processing environment, to identify and detect potential virulence genes isolated from Salmonella in the tea, and to determine the antibiotic resistance levels of Salmonella isolated from fermented Rooibos. / National Research Foundation (NRF)

The oral intake of green tea, black tea and some of the tea constituents has been demonstrated to protect against various diseases and show protective effects on the cell. Tea is able to regulate gene expression, regulate enzymes, regulate the cell cycle, cause cell cycle arrest, induce apoptosis, and inhibit the proteasome. The aim of this study was to find proteins by a proteomic approach that may be modulated in mice drinking tea in contrast to control animals that receive water. Three groups; control, low dose, and a high dose tea group were chosen to determine the effect of tea on protein regulation of C57BL/6 male mice. Daily liquid consumption was measured, and even though the high dose group consumed less liquid they still ingested more tea than the low dose group at the end of the study. Weight gain was measured for all the groups but no significant differences were found. Some differences were found in organ weights of the low and high dose groups. There was no dose dependent effect for the liver and small intestine, while the colon showed a positive and the pancreas a negative dose dependent effect. Small intestine and liver proteins were separated by one and two dimensional gel electrophoresis. No significant differences were found for the small intestine and liver when the proteins were separated by tricine SDS PAGE. However some significant differences were found on the glycine SDS PAGE gels of both the small intestine and the liver. The small intestine had three significant bands at 66kDa, 45kDa and 10kDa. The three significant liver bands were at 110kDa, 66kDa and 14kDa. HPLC analysis of the liver 66kDa band showed that the band consisted of only one protein while the 14kDa band consisted of possibly two proteins. MS analysis of the 14kDa band identified the proteins as hypothetical protein XP_358319 (15 190Da) and immunoglobulin Ą chain (13 140Da). Although the identified proteins match the molecular weight of the 14kDa band these results will need to be confirmed by MudPIT. Thirty 2DE spots of the small intestine were regulated by tea. Ten of these spots were analyzed by MALDI TOF MS, but only seven of these proteins were identified. These proteins were S-phase kinase associated protein p19, hypothetical protein XP_903753, unnamed protein product, adenylyl cyclase-associated protein 2, developmental control protein, lysosomal acid phosphatase, and cytochrome P450 (CYP2D13). All seven the small intestinal proteins will need to be confirmed by de novo sequencing, to ensure the positive identification of the proteins. Currently there is no 2DE map in literature of the small intestine. This study will provide the first 2DE map of the murine small intestine proteins. Thirty three 2DE spots of the liver were regulated by tea. Twenty of these were analyzed by MALDI TOF MS, but only fifteen of these proteins were idenitifed. These regulated proteins are: superoxide dismutase, and glutathione peroxidase that are antioxidant enzymes to counteract oxidative stress, detoxification enzymes like glutathione S-transferase mu-1, glutathione peroxidase theta-1 and cytochrome b5. Annexin A4 is able to help stabilize plasma proteins and the cytoskeleton and may induce apoptosis, keratin 8 may help with network formation and reinforcement of cellular membranes, malate dehydrogenase for energy expenditure and ketohexokinase in carbohydrate metabolism, while ubiquitin conjugating enzyme E2 plays a role in protein turn over. Other identified proteins include inosine-triphosphate-pyrophosphatase, triosephosphate-isomerase, and myoglobin. This study provides a novel 2DE map for liver protein regulation by tea. This was the first study that has taken a proteomic approach to the identification of the overall regulation of proteins by tea. The aim of this study was met by identifying the tea regulated proteins and elaborating on the protective effects and possible cancer chemo preventative effects of tea. / Dissertation (MSc (Biochemistry))--University of Pretoria, 2007. / Biochemistry / unrestricted

Please read the abstract in the section 07back.pdf of this document. / Dissertation (MSc (Biochemistry))--University of Pretoria, 2007. / Biochemistry / unrestricted