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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.
151

Conceptualising women's careers in a developing country : exploring the context of Malawi

Chikapa, Tiyesere January 2018 (has links)
This thesis conceptualises the careers of women in the developing country context of Malawi. A range of 'new' career theories, namely boundaryless, protean, kaleidoscope have been developed in response to the limitations of using traditional theories for studying careers and women's careers in particular. However, these theories have been mostly based on women with interrupted careers in western contexts due to child care reasons. These have also assumed that women have preferences in terms of whether to be career oriented or family oriented. Yet, women in developing and indeed some women in the developed countries have constrained choices and do not pursue interrupted careers. Despite having family responsibilities, they work continuously and mostly full-time. Therefore, there have been calls for more context-specific career studies, especially targeting developing countries. Based on this literature gap, this thesis adopted a qualitative approach to conceptualise the careers of women in Malawi, drawing on the experiences of women in the formal economy, specifically in education and finance and insurance industries. The study finds that the careers of women in Malawi and indeed other women in similar contexts do not fit the existing career perspectives and the proposed 'makeshift' career orientation better explains the studied women's careers. This proposed career concept recognises that careers are a result of compromises that women make when faced with tensions emanating from both the employment and family contexts which simultaneously influence women's careers. The research therefore provides the basis for broadening the existing career perspectives to more adequately reflect the experiences of women, particularly in the developing world. Additionally, the study has adopted an intersectionally-sensitive approach to analysing the employment contexts in two very different sectors. The evidence presented in this thesis gives weight to the intersectional perspective as not only does it find that the actual form of inequality varies but also that the various practices that contribute to inequalities in the different sectors affect different groups of people differently by gender, class and in certain cases region. This contributes to the embryonic literature on intersectionality in terms of both its practice and theory, and understanding how gender and class issues in Malawi may be different from the way these are conceptualised in western contexts.
152

The action of Dang Gui Buxue Tang on key regulators of early atherosclerosis in endothelial cells in vitro.

January 2004 (has links)
Li Tin Wai Olive. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 191-217). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.II / ABSTRACT --- p.III / 中文摘要 --- p.IX / PUBLICATIONS --- p.XIV / TABLE OF CONTENTS --- p.XV / LIST OF ABBREVIATIONS --- p.XXI / LIST OF FIGURES AND TABLES --- p.XXIII / Chapter CHAPTER 1. --- INTRODUCTION --- p.1 / Chapter CHAPTER 2. --- LITERATURE REVIEW --- p.7 / Chapter 2.1. --- Cardiovascular disease --- p.7 / Chapter 2.1.1. --- Introduction --- p.7 / Chapter 2.1.2. --- Atherosclerosis --- p.7 / Chapter 2.1.3. --- Cellular and molecular deregulation in early atherosclerosis --- p.10 / Chapter 2.1.3.1. --- Introduction --- p.10 / Chapter 2.1.3.2. --- Endothelial dysfunction --- p.11 / Chapter 2.1.3.3. --- Nitric oxide --- p.12 / Chapter 2.1.3.4. --- Adhesion molecules and the early events of atherogenesis --- p.13 / Chapter 2.1.3.4.1. --- Introduction --- p.13 / Chapter 2.1.3.4.2. --- Intracellular adhesion molecule-1 --- p.15 / Chapter 2.1.3.4.3. --- Nuclear factor kappa B --- p.18 / Chapter 2.1.3.5. --- Summary --- p.19 / Chapter 2.2. --- Nitric oxide in molecular vascular biology --- p.20 / Chapter 2.2.1. --- Introduction --- p.20 / Chapter 2.2.2. --- Nitric oxide synthase --- p.21 / Chapter 2.2.2.1. --- Introduction --- p.21 / Chapter 2.2.2.2. --- Endothelial nitric oxide synthase --- p.24 / Chapter 2.2.2.3. --- Inducible nitric oxide synthase --- p.25 / Chapter 2.2.2.4. --- Nitric oxide concentration dependent effector pathways --- p.26 / Chapter 2.2.3. --- Nitric oxide and its regulation in vascular events --- p.28 / Chapter 2.2.3.1. --- Introduction --- p.28 / Chapter 2.2.3.2. --- Regulation of vascular tone --- p.30 / Chapter 2.2.3.3. --- "Regulation of platelet adhesion, activation and aggregation" --- p.32 / Chapter 2.2.3.4. --- Regulation of endothelial adhesiveness and leukocyte adhesion - Anti-adhesive effect of nitric oxide --- p.32 / Chapter 2.2.3.5. --- "Regulation of vascular smooth muscle growth, migration and proliferation" --- p.33 / Chapter 2.2.3.6. --- Antioxidative effect of nitric oxide --- p.34 / Chapter 2.2.3.7. --- Regulation of endothelial apoptosis --- p.35 / Chapter 2.2.3.8. --- Nitric oxide and its relationship with other risk factors --- p.36 / Chapter 2.3. --- "Menopause, cardiovascular diseases and Traditional Chinese Medicine" --- p.37 / Chapter 2.3.1. --- Traditional Chinese Medicine and menopause --- p.37 / Chapter 2.3.2. --- Dang Gui Buxue Tang --- p.38 / Chapter 2.3.3. --- Danggui --- p.39 / Chapter 2.3.3.1. --- Botanic origins --- p.39 / Chapter 2.3.3.2. --- Usage --- p.39 / Chapter 2.3.4. --- Huangqi --- p.40 / Chapter 2.3.4.1. --- Botanic origins --- p.40 / Chapter 2.3.4.2. --- Usage --- p.40 / Chapter 2.3.5. --- Modern scientific research --- p.41 / Chapter 2.3.5.1. --- General cardioprotective role --- p.41 / Chapter 2.3.5.2. --- Vascular tone modulation --- p.42 / Chapter 2.3.5.3. --- Haemostasis --- p.42 / Chapter 2.3.5.4. --- Endothelial cell --- p.43 / Chapter 2.3.5.4.1. --- Nitric oxide pathway --- p.43 / Chapter 2.3.5.4.1.1. --- Direct alteration of nitric oxide secretion --- p.43 / Chapter 2.3.5.4.1.2. --- Alteration of Nitric oxide synthase expression or activity --- p.43 / Chapter 2.3.5.4.2. --- Alteration of adhesion molecule expression --- p.44 / Chapter 2.3.5.4.3. --- Alteration of adhesion molecule expression as an effect of nitric oxide secretion --- p.45 / Chapter 2.3.5.5. --- Antioxidant effect --- p.45 / Chapter 2.3.5.6. --- Estrogenicity of DBT --- p.46 / Chapter 2.4. --- Research plan --- p.47 / Chapter 2.4.1. --- Formulation of research hypotheses --- p.47 / Chapter 2.4.1.1. --- Hypotheses --- p.50 / Chapter 2.4.2. --- Plan of study --- p.50 / Chapter 2.4.2.1. --- Dang Gui Buxue Tang extraction and standardization of content --- p.50 / Chapter 2.4.2.2. --- Cell model development --- p.52 / Chapter 2.4.2.3. --- Experimental studies --- p.54 / Chapter 2.4.2.4. --- eNOS activity determination - the nitric oxide metabolite assay --- p.56 / Chapter 2.4.2.5. --- Endotoxin contamination in DBT --- p.57 / Chapter 2.4.3. --- Sample size and statistical analysis --- p.59 / Chapter CHAPTER 3. --- MATERIALS AND METHODS --- p.62 / Chapter 3.1. --- Dang Gui Buxue Tang extraction and content standardization --- p.62 / Chapter 3.1.1. --- Plant materials --- p.62 / Chapter 3.1.2. --- DBT authentication --- p.62 / Chapter 3.1.3. --- DBT processing prior to extraction --- p.63 / Chapter 3.1.4. --- DBT extraction --- p.63 / Chapter 3.1.5. --- Quantitative standardization of DBT markers by High Pressure Liquid Chromatography --- p.66 / Chapter 3.1.5.1. --- DBT markers: standard preparation --- p.66 / Chapter 3.1.5.2. --- Sample preparation --- p.67 / Chapter 3.1.5.3. --- Quantitative analysis of DBT constituents by HPLC --- p.67 / Chapter 3.1.6. --- DBT polysaccharide standardization --- p.68 / Chapter 3.1.6.1. --- Glucose standard preparation --- p.68 / Chapter 3.1.6.2. --- Sample preparation --- p.68 / Chapter 3.1.6.3. --- Quantitative determination of polysaccharide by Phenol-Sulfuric acid colorimetric assay --- p.68 / Chapter 3.1.7. --- DBT endotoxin contamination determination --- p.69 / Chapter 3.1.7.1. --- "Positive, negative and inhibition controls" --- p.69 / Chapter 3.1.7.2. --- Qualitative determination of sample endotoxin --- p.70 / Chapter 3.2. --- Cell culture --- p.70 / Chapter 3.2.1. --- Characterization of cultured cells --- p.72 / Chapter 3.2.2. --- Passage --- p.73 / Chapter 3.3. --- DBT treatment --- p.73 / Chapter 3.3.1. --- Solvent system of DBT treatment --- p.73 / Chapter 3.3.2. --- Dosage and duration of DBT treatment --- p.74 / Chapter 3.3.3. --- Positive and negative controls --- p.74 / Chapter 3.4. --- MTT-based cytotoxicity assay --- p.75 / Chapter 3.5. --- Reverse transcriptase- polymerase chain reaction --- p.76 / Chapter 3.5.1. --- Sample preparation --- p.76 / Chapter 3.5.1.1. --- Total RNA isolation --- p.76 / Chapter 3.5.1.2. --- DNase treatment --- p.77 / Chapter 3.5.1.3. --- RNAethanol precipitation --- p.78 / Chapter 3.5.1.4. --- Complementary DNA synthesis --- p.78 / Chapter 3.5.2. --- Polymerase chain reaction --- p.79 / Chapter 3.5.2.1. --- Polymerase chain reaction conditions --- p.79 / Chapter 3.5.2.2. --- Primers --- p.79 / Chapter 3.5.3. --- Visualization of the PCR products --- p.81 / Chapter 3.5.3.1. --- Gel electrophoresis --- p.81 / Chapter 3.5.3.2. --- Gel Doc software --- p.82 / Chapter 3.5.3.3. --- Densitometry --- p.82 / Chapter 3.5.4. --- Real time RT-PCR --- p.82 / Chapter 3.6. --- Quantitative Immunocytochemical studies --- p.84 / Chapter 3.6.1. --- Coverslip preparation --- p.84 / Chapter 3.6.2. --- Sample preparation --- p.84 / Chapter 3.6.3. --- Immunocytochemical staining preparation --- p.85 / Chapter 3.6.3.1. --- "Immunocytochemical staining for vWF, α-actin, iNOS, ICAM-1, NF-kB using DAKO catalyzed signal amplification (CSA) system (anti-mouse)" --- p.86 / Chapter 3.6.3.2. --- Immunocytochemical staining for eNOS using Santa Cruz immunoCruz staining system (anti-goat) --- p.87 / Chapter 3.6.4. --- Counterstaining and mounting --- p.88 / Chapter 3.6.5. --- Result interpretation --- p.89 / Chapter 3.6.5.1. --- Microscopy and digital image capture --- p.89 / Chapter 3.6.5.2. --- Determination of Image (file) Energy --- p.89 / Chapter 3.7. --- Total Nitrite/Nitrate quantitative colorimetric assay --- p.90 / Chapter 3.7.1. --- Sample preparation --- p.90 / Chapter 3.7.2. --- Total Nitrite/Nitrate quantitative colorimetric assay --- p.91 / Chapter CHAPTER 4. --- RESULTS --- p.93 / Chapter 4.1. --- Dang Gui Buxue Tang extraction and standardization of content --- p.93 / Chapter 4.1.1. --- DBT extraction - general data --- p.93 / Chapter 4.1.2. --- DBT polysaccharide standardization --- p.97 / Chapter 4.1.3. --- DBT marker standardization --- p.101 / Chapter 4.1.4. --- DBT endotoxin contamination determination --- p.104 / Chapter 4.2. --- Cell model development --- p.108 / Chapter 4.2.1. --- Endothelial morphology --- p.108 / Chapter 4.2.2. --- Immunocytochemistiy --- p.108 / Chapter 4.2.3. --- MTT cytotoxicity assay --- p.110 / Chapter 4.3. --- Study 1 --- p.112 / Chapter 4.3.1. --- Immunocytochemistry (Hypothesis 1) --- p.112 / Chapter 4.3.2. --- RT-PCR (Hypothesis 1) --- p.117 / Chapter 4.3.3. --- Real time RT-PCR (Hypothesis 1) --- p.121 / Chapter 4.3.4. --- Immunocytochemistry (Hypothesis 2) --- p.125 / Chapter 4.3.5. --- RT-PCR (Hypothesis 2) --- p.128 / Chapter 4.3.6. --- Total Nitrite/Nitrate quantitative colorimetric assay --- p.131 / Chapter 4.4. --- Study 2 --- p.133 / Chapter 4.4.1. --- Immunocytochemistry --- p.133 / Chapter 4.5. --- Study 3 --- p.138 / Chapter 4.5.1. --- Immunocytochemistry --- p.138 / Chapter 4.5.2. --- RT-PCR --- p.141 / Chapter 4.5.3. --- Real time RT-PCR --- p.145 / Chapter 4.6. --- Endotoxin contamination in DBT --- p.149 / Chapter 4.6.1. --- Effects of endotoxin on eNOS --- p.149 / Chapter 4.6.2. --- Immunocytochemistry on immunostained endothelial cells --- p.151 / Chapter 4.6.3. --- Effects of endotoxin on iNOS --- p.153 / Chapter 4.6.4. --- Effect of endotoxin on NF-kB --- p.157 / Chapter 4.6.5. --- Effects of endotoxin on ICAM-1 --- p.160 / Chapter CHAPTER 5. --- DISCUSSION --- p.165 / Chapter 5.1. --- DBT extraction and standardization of content --- p.165 / Chapter 5.1.1. --- Optimal DBT extraction conditions --- p.165 / Chapter 5.1.2. --- Evidence to support formulae usage --- p.166 / Chapter 5.1.3. --- Limitation of the methodology used --- p.166 / Chapter 5.2. --- Cell model development --- p.167 / Chapter 5.2.1. --- Choice of DBT concentration range in the study --- p.167 / Chapter 5.2.1.1. --- Choice of concentration range in consideration of endotoxin contamination --- p.167 / Chapter 5.2.1.2. --- Choice of concentration range in consideration of DBT's cytotoxicity effects --- p.168 / Chapter 5.2.1.3. --- Choice of concentration range in consideration of prevous studies --- p.168 / Chapter 5.3. --- Study 1 --- p.169 / Chapter 5.3.1. --- Action of DBT on eNOS expression --- p.169 / Chapter 5.3.2. --- Action of DBT on iNOS expression --- p.170 / Chapter 5.3.3. --- Action of DBT on Nitric oxide metabolite assay --- p.171 / Chapter 5.3.3.1. --- Result interpretation with rejected hypothesis 2 --- p.171 / Chapter 5.3.3.2. --- Assay limitations and improvements --- p.171 / Chapter 5.4. --- Study 2 --- p.172 / Chapter 5.4.1. --- Action of DBT on NF-kB expression --- p.172 / Chapter 5.4.2. --- Assay limitations and improvements --- p.173 / Chapter 5.5. --- Study 3 --- p.174 / Chapter 5.5.1. --- Action of DBT on ICAM-1 expression --- p.174 / Chapter 5.6. --- Endotoxin contamination in DBT --- p.175 / Chapter 5.6.1. --- Action of endotoxin contamination in DBT on various markers --- p.175 / Chapter 5.6:2. --- Experimental limitation --- p.176 / Chapter 5.6.3. --- Endotoxin removal --- p.177 / Chapter 5.6.3.1. --- Introduction --- p.177 / Chapter 5.6.3.2. --- Endotoxin removal methodologies suitable for herbal use --- p.179 / Chapter 5.7. --- Action of DBT on angiogenesis stimulation --- p.181 / Chapter 5.7.1. --- Evidence for DBT's proangiogenic effects from various studies --- p.181 / Chapter 5.7.2. --- Influence of endotoxin contamination on angiogenesis stimulation --- p.182 / Chapter 5.7.3. --- Assay limitations and future developments --- p.183 / Chapter CHAPTER 6. --- GENERAL DISCUSSION AND SUMMARY --- p.186 / Chapter CHAPTER 7. --- REFERENCES --- p.191
153

Nomads in contested landscapes : reframing student engagement and non-traditionality in higher education

Trowler, Vicki Brenda Agnes January 2017 (has links)
The findings of this study challenge essentialised conceptions of “the student” as a young national, entering higher education directly from school with appropriate school-leaving qualifications, to devote themselves entirely to their studies, undistracted by caring responsibilities or work commitments, unconstrained by disabilities, conforming to an unproblematised binary conception of gender which informs an appropriate choice of study programme, participating in stereotypical student extramural pursuits along the way. The study tracked 23 students from 7 universities who volunteered themselves as ‘non-traditional’ in their own study contexts over the course of a calendar year. Drawing on concepts of ‘diaspora space’, ‘nomadism’, dis/identification and mis/recognition, this study maps out these students’ perceptions of the different aspects of their engagement as these changed over time as well as their self-conceptions and their descriptions of their ‘imagined communities’. The importance of relationships of different kinds (with other people, with their studies, and with their universities and other structures) in their decisions about persistence is noted. Student Engagement (SE) has been widely accepted as contributing positively to the student experience, student success and outcomes, including persistence / retention. ‘Non-traditional’ students, while having the potential to benefit most from SE, are often reported as feeling unengaged or alienated, and constitute ‘at risk’ groups in terms of persistence / retention. This study has established that the construct ‘non-traditional student’ can be considered a ‘chaotic conception’, since students bearing that label may have nothing in common beyond not conforming to ‘traditional’ criteria. Students may consider themselves ‘non-traditional’ in their particular study contexts for many reasons, often presenting with more than one factor from a checklist of what is not traditional in that context. The study also found reported mismatches between resources and services offered by universities for defined groups of ‘non-traditional’ students, and the support sought by students in this study. These mismatches hinge on factors such as fear of stigma, disparities between how target groups are defined and how students self-identify, opacity of systems and processes and perceived differences in priority.
154

Stakeholders' perceptions of the changing role of traditional birth attendants in the rural areas of central Wets zone, Malawi: a mixed methods study

Banda, Evelyn Chitsa 28 March 2014 (has links)
Introduction: In 2007, the Ministry of Health in Malawi issued a directive banning traditional birth attendants (TBAs) from delivering mothers and ordered all mothers to access skilled birth attendants in health facilities (MoH, 2007b). Anecdotal reports showed that the influx of pregnant mothers to the health facilities resulted in mothers delivering on make shift beds on the floor and sometimes without the assistance of the skilled provider. The badly stretched health care system continues to force mothers to deliver with the assistance of TBAs who have gone underground for fear of being fined. Purpose of the study: The purpose of this study was to explore stakeholders’ perceptions of the changing role of TBAs in order to obtain a greater breadth of understanding of the reasons why home births persist in the rural areas of Central West Zone (CWZ), Malawi. Methods: The study employed a mixed method concurrent triangulation design in which 24 health facilities in the districts of Ntcheu, Dedza, Lilongwe and Mchinji, in CWZ, Malawi were included. A non-probability purposive sampling method was used to select 24 health facilities that provide Basic Emergency Obstetric and Neonatal Care (BEmONC) services in rural areas of CWZ. A randomly selected sample was used to collect quantitative data from mothers, using an interview schedule. These were mothers (n=144) who had come to access maternal and neonatal health care but had previously sought the help of a TBA to deliver. A total of 55 nurse midwives who worked in the 24 health facilities and who were available and willing to participate responded to a structured interview schedule. Quantitative data were analyzed using SPSS version 19. Qualitative data were collected using focus group discussions (FGDs) with TBAs (n=4 FGDs, with 6-7 respondents in each discussion group) who lived in the catchment areas of the selected BEmONC sites. Single in- depth interviews were conducted with TBA trainers (n=10) in the districts and health professionals (n=12) from the Ministry of Health and Nurses and Midwives Council of Malawi. Data were analyzed manually. Findings: The findings showed that the moratorium on TBAs was implemented without consultation with the relevant stakeholders and as a result, many mothers in rural areas continued to seek the services of TBAs. Untrained TBAs took advantage of the opportunity and together with some trained TBAs who were afraid of punishment went underground to practice. Maternal and neonatal health care in BEmONC facilities were deficient as the health care system struggled with challenges such as the lack of adequate and humane accommodation for waiting mothers, critical shortages of staff, drugs and supplies and negative health care worker attitudes. In addition, long distances and the lack of empowerment of rural women prevented mothers from seeking skilled birth attendants. The study concluded that even though the government had issued a moratorium on TBAs, the health care system is not coping. Recommendations: It is recommended that having moved away from the TBAs, there is no need to revert to using them since that would mean perpetuating harmful and substandard care for mothers. In addition, TBA services would undermine the government’s efforts to improve skilled birth attendance. However, the system needs to urgently deal with the challenges that rural mothers encounter in trying to access skilled birth attendance.
155

Recent developments in research on terrestrial plants used for the treatment of malaria.

Wright, Colin W. January 2010 (has links)
no / New antimalarial drugs are urgently needed to combat emerging multidrug resistant strains of malaria parasites. This Highlight focuses on plant-derived natural products that are of interest as potential leads towards new antimalarial drugs including synthetic analogues of natural compounds, with the exception of artemisinin derivatives, which are not included due to limited space. Since effective antimalarial treatment is often unavailable or unaffordable to many of those who need it, there is increasing interest in the development of locally produced herbal medicines; recent progress in this area will also be reviewed in this Highlight.
156

Nkanelo wa nkoka wa vukosi bya ndhavuko eka nkarhi wa sweswi hi ku kongomisa eka vukosi bya ka Muhlaba

Hlungwane, Rose January 2013 (has links)
Thesis ( M.A. (African Languages)) --University of Limpopo, 2013 / Refer to document
157

Going Forward by Looking Back : How returning to traditional peace-making can increase legitimacy through the peace-making process

Fors Magnström, Sandra January 2019 (has links)
Liberal peace-making may not always be the best way to ensure peace in conflicting societies. Academia have always tended to only look to Western peace-making processes which have made policy limited in the cultural understanding of societies way of functioning, trying to implement what may work in "Western" but not necessarily the host countries' context. In addition, fewer have looked how these two contrasting ways of conducting peace-making affects legitimacy. In this thesis, I examine how Mac Ginty's (2008) "liberal peace versus traditional peace-making" affects level of legitimacy as conceptualized by Levi et al. (2009), within the case of Somalia. The hypothesis was confirmed; the use of traditional peace-making processes has a positive effect on legitimacy. To conclude, the recommendation for further research was to explore the grey-zones between liberal peace and traditional peace-making to further explore its possibilities.
158

Effects of planting date and location on phenology, yield and yield components among selected cowpea varieties.

Shiringani, Rhandzu Patience. January 2007 (has links)
Thesis (M.Sc) (Agriculture)--University of Limpopo, 2007. / Cowpea (Vigna unguiculata L. Walp) is one of the important food legumes and a valuable component of the traditional cropping systems. It serves as a source of protein in human diet and plays a major role in animal nutrition. The crop is adaptable to harsh environments including extreme temperatures and water limiting conditions. There is limited information available in cowpea with regards to cultivar selection and performance studies across ranges of environments in South Africa. The objectives of the present study were to 1) determine the influence of different planting dates and locations on phenology, yield and yield components of selected cowpea varieties and 2) determine the relationship of seed yield to environmental conditions such as rainfall and temperature. Ten cowpea genotypes were used for the study, developed by the Agricultural Research Council, Grain Crops Institute, South Africa. The experiment was laid out in a randomized complete block design with three replications. The experiment was carried out at Potchefstroom, Taung (Northwest Province) and Syferkuil (Limpopo Province) during three planting dates viz. 8 Nov. 22 Nov and 6 Dec. 2004. Data collected included the number of days to 50% flowering, number of days to 50% physiological maturity, seed yield, number of branches per plant, number of pods per plant, number of seeds per pod and 100 seed weight. The results showed highly significant differences among cowpea genotypes in each location and across locations for yield and yield components. Planting date one (i.e. 08 November) was better in yield gain over all locations. Potchefstroom was the best location for best yield gain due to high rainfall and relatively favorable low temperatures. The lowest yield was recorded at Syferkuil because of low rainfall and high temperatures. With relatively better performance across locations IT18E-16, CH14 and Pan311 were the best genotypes recommended in these or other similar environments in South Africa. / National Research Foundation (NRF)and Agricultural Research Council (ARC)
159

An investigation into aspects of medicinal plant use by traditional healers from Blouberg Mountain, Limpopo Province, South Africa

Mathibela, Khomotso Malehu January 2013 (has links)
Thesis (M.Sc. (Botany)) -- University of Limpopo, 2013 / Traditional medicine plays a major role in the primary health care of many people residing in rural areas. People in these areas still consult traditional healers who utilise plants as medicine. Medicinal plants have come under increasing pressure due to a number of factors, which have resulted in the decline of certain species, extinction in others, and a general decrease in biodiversity of high use areas of South Africa, Blouberg Mountain included. To date there has been a lack of information on how traditional healers utilise the Blouberg Mountain with respect to amounts and species removed, or where the most important collecting sites are located. Thus, no conservation strategy exists for the Blouberg Mountain to ensure sustainable management of its natural resources. Furthermore, there is a perception amongst elders of this area that, as with indigenous knowledge around the world, the knowledge centered around Blouberg’s medicinal plants is declining, and little formal documentation of that knowledge has taken place. Consequently, this study investigated aspects related to medicinal plant use such as collection, patterns of collection, legislation, storage and packaging of medicinal plants by traditional healers around Blouberg Mountain. These were documented via a semi-structured questionnaire and a data collection sheet. Furthermore, traditional harvesting methods employed by traditional healers, and in situ conservation issues related to species removal from the mountain were investigated. Data was collected between September 2010 and September 2011. Sixteen villages in close proximity to the mountain, and 32 healers (two per village) were selected. In addition 16 consulting rooms were sampled (one per village) in order to gather information on the number of species collected from the mountain and stored in the consulting rooms. The 16 most used (indicated by village traditional healers) collection tracks, (one per village surrounding Blouberg Mountain), were travelled with traditional healers to record botanical and vernacular names of the medicinal plants, vegetation type, habitat, parts used, harvesting method, replacement value of plant species and perceived rarity of collected material. A Garmin GPS was used to record waypoints for the beginning and end of each track. Co-ordinates were logged automatically every 10 m. A map using Quantum GIS software to capture the position of the healers’ collection tracks, overlaid with topographical and vegetation information, and protected area information of the Blouberg Mountain, was generated. Geographic Information System software was used to geo-process the collection tracks of the healers with respect to where medicinal plants were collected relative to the various vegetation types. This gave information on vegetation types important to healers. The majority of traditional healers were females. Most of them had no formal education, with only a minority reaching secondary school. Due to their low level of literacy they tended to shy away from sources of written information, with the result that none of the questioned healers had any knowledge of the various national or provincial environmental legislations. The majority of them see between 15 and 20 patients per month. Most of the healers had more than 30 years of experience in traditional healing. The study found 64 plant species commonly used for medicinal purposes. Most of them were harvested for their roots and bark. According to the healers, Boophane disticha and Hypoxis hemerocallidea are declining in Blouberg Mountain, with Warburgia salutaris, endangered in South Africa, not perceived as rare or declining. However, a number of plant species recorded in the Red Data List as of least concern, or not threatened, are seen as rare by the healers. These include Clivia caulescens, Erythrina lysistemon, Lannea schweinfurthii and Maerua juncea. No exotic species were documented from the surveyed tracks. However, two naturalised exotics were collected from the mountain, namely Cassytha filiformis and Corchorus tridens. Cocculus hirsutus, a naturalised exotic and Abrus precatorius, an exotic species were found in one of the consulting rooms. Dichrostachys cinerea, Philenoptera violacea and Tarchonanthus camphoratus, which are indicators of bush encroachment, were identified on selected tracks. Tracks on which indicators of bush encroachment are present should be investigated more thoroughly to ascertain the extent and severity of such a threat. vii Investigations into healers’ collection tracks showed that the Soutpansberg Mountain Bushveld vegetation type is the most heavily utilised of the five vegetation types around Blouberg Mountain. This vegetation type is vulnerable to human population densities as most species were collected from it, therefore it should be conserved and managed if possible as it is targeted for plant species of medicinal value. The most travelled tracks were found in the Catha-Faurea Wooded Grassland community. Solutions to the problems of over harvesting of medicinal plants require local innovations and the full participation of traditional healers in resource management initiatives. The development of medicinal plant nurseries together with propagation of key species will be a crucial management tool, as this will reduce over harvesting of natural resources from the wild. In conclusion, it was found that although most species utilised around Blouberg Mountain are abundant and not threatened, healers are nevertheless concerned about dwindling medicinal plant supplies. They would welcome conservation initiatives and the use of GIS maps would be useful in prioritising conservation areas.
160

A search for biologically active compounds in Acacia (Mimosaceae) species

Wickens, Kristen M. January 2003 (has links)
Indigenous Australians were also known to use plants for medicinal purposes. For thousands of years, Indigenous Australians have used native plants as a source of medicinal agents. Some tribes living in Central Australia still, to this day, prefer to use traditional medicines in favour of the more common and readily available western medicines. A number of plant species endemic to Australia are listed in various Aboriginal pharmacopoeias, with approximately one-third of those species belonging to two genera, Acacia and Eremophila. Of the 1100 recognised species of Acacia, approximately 900 occur in Australia. At least thirty of these species were utilised by the Indigenous Australians as a source of medicine. Extracts of 8 Acacia species were screened using four frontline bioassays. These were the brine shrimp lethality test, the crown gall tumour assays, the disc diffusion antibiotic assay and the seed germination test to determine if any of the species were biologically active. Of all the species screened, Acacia pruinocarpa showed the most promise. The species demonstrated significant activity at concentrations at low as 3.7ppm, which is well below the standard 400ppm exhibited by potassium dichromate (Sam, 1993). Acacia adsurgens and A. dictophleba were the next two promising species exhibiting activity at concentrations of 16.12ppm and 37ppm respectively. This was a trend that was also observed in the Lettuce seed germination test for allelopathy with these three species showing the most promise. Interestingly the potency of A. pruinocarpa extract decreased significantly when it was re- screened after being put through a polyamide column. It can therefore be suggested that as tannins are removed by the polyamide column, the biological activity exhibited by A. pruinocarpa is a result of the tannin content in the species (2%), although more testing is required. / Both A. pruinocarpa and A. adsurgens showed promise as anti-tumour activity when used in the Crown Gall Tumour Assay (CGTA). Acacia pruinocarpa and A. adsurgens both exhibited significant activity when compared to the control producing inhibition percentages of 31% and 37% respectively. Surprisingly, only one of the Acacia species tested inhibited pathogenic growth when tested on the common pathogens Staphylococcus aureus, Streptococcus pyogens and Candida albicans. Acacia bivenosa was the only species to exhibit any activity when tested on the pathogens. This activity, however is not considered to be significant, as the species was only active against one of pathogens tested, Staphylococcus aureus. In order to be considered to be significant, a species must be active against two or more pathogens. It is however, worthy of further evaluation. Acacia species are among the large number of plants that have long been regarded sources of biological activity. This study was guided by the indigenous use of Acacia species as sources of medicine, which led to the use of front-line bioassays. All of the species tested exhibited some form of biological activity. Acacia pruinocarpa demonstrated the most promise as a source of novel biologically active compounds exhibiting activity at very low concentrations. Such compounds have not been determined as it was outside the scope of this study to identify the active constituents of this species. However, it has been suggested that tannins are responsible for eliciting some of the activity observed in A. pruinocarpa. All of the species screened in this study are worthy of further evaluation. The bioassays used in this study are good examples of front-line bioassays. All of the tests used in the study fulfil the criterion, which defines a good test.

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