Gravitational entropy and thermodynamics away from the horizon
- Authors: Brustein, R , Medved, A J M
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6818 , http://hdl.handle.net/10962/d1004328
- Description: We define, by an integral of geometric quantities over a spherical shell of arbitrary radius, an invariant gravitational entropy. This definition relies on defining a gravitational energy and pressure, and it reduces at the horizon of both black branes and black holes to Wald's Noether charge entropy. We support the thermodynamic interpretation of the proposed entropy by showing that, for some cases, the field theory duals of the entropy, energy and pressure are the same as the corresponding quantities in the field theory. In this context, the Einstein equations are equivalent to the field theory thermodynamic relation TdS=dE+PdV supplemented by an equation of state
- Full Text:
Graviton n-point functions for UV-complete theories in Anti-de Sitter space
- Authors: Brustein, R , Medved, A J M
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: vital:6820 , http://hdl.handle.net/10962/d1004427
- Description: We calculate graviton n-point functions in an anti-de Sitter black brane background for effective gravity theories whose linearized equations of motion have at most two time derivatives. We compare the n-point functions in Einstein gravity to those in theories whose leading correction is quadratic in the Riemann tensor. The comparison is made for any number of gravitons and for all physical graviton modes in a kinematic region for which the leading correction can significantly modify the Einstein result. We find that the n-point functions of Einstein gravity depend on at most a single angle, whereas those of the corrected theories may depend on two angles. For the four-point functions, Einstein gravity exhibits linear dependence on the Mandelstam variable s versus a quadratic dependence on s for the corrected theory.
- Full Text:
Guy Butler’s South Africanism: ‘Being present where you are’
- Authors: Wright, Laurence
- Date: 2012
- Language: English
- Type: text , article
- Identifier: vital:7069 , http://hdl.handle.net/10962/d1007460 , https://doi.org/10.1080/10131752.2012.730182
- Description: preprint , A peer-reviewed lecture delivered at Rhodes University on the occasion of the presentation to Professor Wright of the English Academy's Gold Medal, 16 November 2011. Guy Butler (1918-2001) has been gone some ten years. This lecture sets out to illuminate the thinking behind his important role in South Africa's national life. The institutions he created continue to make vital cultural contributions in South Africa's efforts to make sense of its own complex historical make-up, working towards a happier, richer, and more equal future. However, despite what he achieved, there is little surety that today the rationale informing his massive effort to foster processes of artistic and cultural endeavour has been appreciated or accurately understood.
- Full Text:
Haul Music : transnationalism and musical performance in the Saharaui refugee camps of Tindouf, Algeria
- Authors: Gimenez Amoros, Luis
- Date: 2012
- Subjects: Bedouins -- Music -- Research Sahrawi (African people) -- Migrations Social change -- Arab countries Arab countries -- Social life and customs Civilization, Arab
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2637 , http://hdl.handle.net/10962/d1002302
- Description: The thesis presents ethnographic data and musical analysis (in the form of transcriptions) of Haul music which is the music style performed by Bedouin societies in Trab el Bidan region (Mauritania, Western Sahara, northern Mali, southern Algeria and northern Morocco). It is based on field research undertaken in Algeria in 2004-05 in the refugee camps of Tindouf, Algeria, where Saharaui people (a Bedouin society)live in exile. This research is unique and original as Haul has not, until now, been explored in depth by any scholar. My research on Haul reveals that the changes in Saharaui music in the refugee camps of Tindouf reflect changes in the musical traditions of Bedouin societies as whole; changes that can be traced to the revolution which occurred in Western Sahara in 1975, and changes that are a result of the migrations and life in exile that followed. I argue that these changes occurred due to the transnational experiences undergone by Saharaui people in their forced exile (caused by the Moroccan state) from their homeland in Western Sahara to Algeria. Further, I assert that the invocation of memory in Bedouin musical styles is evidence of past musical practices being retained in contemporary Haul performance, although other musical changes are similarly in progress.
- Full Text:
Having a phone, having style:
- Authors: Schoon, Alette
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159506 , vital:40303 , https://hdl.handle.net/10520/EJC135828
- Description: It was dusk, and a group of young men with a dog trailing behind them, were walking past on a dusty township road in Hooggenoeg, an RDP village on the rim of the Grahamstown bowl. While they ambled along, one was holding up a mobile phone on which music was playing, dancing while he walked. This was exactly the kind of thing I was hoping to observe in my new identity as researcher and participant observer, and was why I had agreed to judge the Hooggenoeg fashion show which turned out to be more of a beauty competition. While I'm not generally fond of these kind of shows and the way they essentialise beauty, I agreed because I wanted to get more of a sense of how mobile phones are integrated into the everyday lives of these young adults.
- Full Text:
Henry Williams : The Glasbury Bellfounder, and the production and tuning of bells
- Authors: Lewis, Colin A
- Date: 2012
- Language: English
- Type: Book chapter
- Identifier: vital:6159 , http://hdl.handle.net/10962/d1004779 , Full text available to the end of Chapter 2
- Description: The production and tuning of church bells is described before attention is paid to Henry Williams, the Glasbury bellfounder who died in 1722, and his bells. The bells of TP, his apparent successor are also described. Henry Williams was probably a member of the Williams family of Gwernyfed and was born c 1635. His presumed family connections are described. Bells known to have been cast by Henry Williams between 1677 and 1719 are listed; their distribution depicted; and their qualities assessed. The inventory of Williams' possessions at the time of his death is presented and discussed. Bells cast by TP during a brief foray into bell founding, apparently 1738-40, are described and their qualities assessed. TP was probably Benjamin Tanner (T), the industrialist specialising in iron production who succeeded Williams at the Pipton forge (P) in Aberllynfi parish near Glasbury, or Tanner (T) and Samuel Prichard (P). Prichard was the grandson of Henry Williams and his sole executor. , A complete copy of this book is available at The Whiting Society of Ringers at: http://www.whitingsociety.org.uk
- Full Text:
High pressure liquid chromatographic quantification of nitrile biocatalysis
- Authors: Mathiba, Kgama
- Date: 2012
- Subjects: High performance liquid chromatography , Rhodococcus , Biocatalysis , Organic compounds -- Industrial applications
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4129 , http://hdl.handle.net/10962/d1015710
- Description: Nitrile biocatalysts are of use in the chemical and pharmaceutical industries for the synthesis of carboxyamides and carboxylic acids. In particular, the application of biocatalysts in the synthesis of single enantiomer compounds is of increasing interest, but requires novel substrate specific highly stereoselective biocatalysts. Addition to the limited toolbox of known nitrile biocatalysts requires definitive characterisation of the biocatalysts through accurate determination of the substrate profiles and quantification of activity. The accurate quantification of stereoisomers chiral mixtures to determine biocatalyst stereoselectivity remains a significant challenge due to the difficulty in separating stereoisomers by physical methods. The known nitrile metabolising organism, Rhodococcus rhodochrous ATCC BAA-870, was grown in a defined medium and harvested, providing whole cell biocatalyst. Additional biomass was disrupted to provide a cell free enzyme extract, which was put through an enzyme purification protocol to provide a solution with specific activity of 351 U.mg⁻¹. A portion of the enzyme was self immobilised using the SphereZyme™ technique. The nitrile hydratase SphereZymes™ (1.2 U.mg⁻¹ initial activity) that were prepared had pH and temperature optima of 6 and 30°C respectively, and could be recovered by repeated washing. The particles retained activity in the presence of the organic solvents isooctane and n-hexadecane saturated with 50 mM phosphate buffer (pH 7.5). An initial analytical system was devised for quantification of the nitrile hydratase activity using the non-chiral substrate benzonitrile. An improved reversed phase high performance liquid chromatography method was developed to separate and quantify benzamide, benzoic acid and benzonitrile. The mobile phase consisting of 0.1% trifluoroacetic acid in H₂O and acetonitrile (70:30, %v/v), at a flow rate of 0.5 ml.ml⁻¹, 25°C, resolved all three analytes in 3.5 minutes on a Waters X-Terra MS C18 3.5μm column. UV detection was carried out at 210 nm. Analytical methods to determine activity and enantioselectivity of the whole cell biocatalyst were subsequently developed for both β-amino nitriles and β-hydroxy nitrile substrates and hydrolysis products.
- Full Text:
Higher education, academic communities, and the intellectual virtues
- Authors: Jones, Ward E
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275647 , vital:55066 , xlink:href="https://doi.org/10.1111/edth.12005"
- Description: Because higher education brings members of academic communities in direct contact with students, the reflective higher education student is in an excellent position for developing two important intellectual virtues: confidence and humility. However, academic communities differ as to whether their members reach consensus, and their teaching practices reflect this difference. In this essay, Ward Jones argues that both consensus-reaching and non-consensus-reaching communities can encourage the development of intellectual confidence and humility in their students, although each will do so in very different ways.
- Full Text:
How do HIV and AIDS impact the use of natural resources by poor rural populations?: The case of wild animal products
- Authors: Kaschula, Sarah , Shackleton, Charlie M
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182344 , vital:43822 , xlink:href="https://hdl.handle.net/10520/EJC97203"
- Description: As a result of heightened financial and food insecurity, populations adversely affected by HIV and/or AIDS may be more likely to utilise wild natural resources to supplement their diet and livelihoods. Should this effect be pronounced, HIV and AIDS may pose a serious environmental threat. We explored the hypothesis that the presence of factors in the household, such as chronic illness in and recent mortality of individuals in a high HIV-risk age group, as well as the fostering of orphans, are associated with increased utilisation of wild animal products (WAPs) at the household level. We randomly surveyed 519 households from four sites in rural South Africa, recording household socio-economic status, the utilisation of wild animal products and health and demographic factors attributed to HIV or AIDS. Binary logistic regressions were used to test if households with markers of HIV and/or AIDS affliction were more likely to have a higher incidence and frequency of WAP utilisation relative to non-afflicted households, after adjusting for socio-economic and demographic variables. We found that, although households with markers of HIV and/or AIDS were generally poorer and had higher dependency ratios, there was no evidence to support the hypothesis that WAP harvesting was associated with either poverty, or markers of HIV and/or AIDS affliction. Our findings suggest that generalisations about a possible interaction between HIV and/or AIDS and the environment may not uniformly apply to all categories of natural resources or to all user groups.
- Full Text:
Human rights and post-conflict peace building in the Democratic Republic of Congo
- Authors: Juma, Laurence
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/128438 , vital:36109 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC192855
- Description: This article deals with normative issues that arose in the post-conflict peace-building processes in the Democratic Republic of Congo (DRC). It undertakes an historical review of the major episodes in the DRC peace process and highlights how these episodes yielded to the establishment of the interim government in 2003 and the enactment of the current constitution. It mainly highlights the proprietary consequences of the Lusaka peace Accord, the transformative aspects of the 2005 Constitution and the role that international organs, especially the ICC, have played in consolidating peace in the DRC.
- Full Text: false
Hydrological uncertainty analysis and scenario-based streamflow modelling for the Congo River Basin
- Authors: Tshimanga, Raphael Muamba
- Date: 2012
- Subjects: Congo River -- Regulation Hydrological surveys -- Congo River Watershed Water resources development -- Congo River Watershed Water resources development -- Environmental aspects -- Congo River Watershed Water supply -- Congo River Watershed River engineering -- Congo River Watershed
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6029 , http://hdl.handle.net/10962/d1006158
- Description: The effects of climate and environmental change are likely to exacerbate water stress in Africa over the next five decades. It appears obvious, therefore, that large river basins with considerable total renewable water resources will play a prominent role in regional cooperation to alleviate the pressure of water scarcity within Africa. However, managing water resources in the large river basins of Africa involves problems of data paucity, lack of technical resources and the sheer scale of the problem. These river basins are located in regions that are characterized by poverty, low levels of economic development and little food security. The rivers provide multiple goods and services that include hydro-power, water supply, fisheries, agriculture, transportation, and maintenance of aquatic ecosystems. Sustainable water resources management is a critical issue, but there is almost always insufficient data available to formulate adequate management strategies. These basins therefore represent some of the best test cases for the practical application of the science associated with the Predictions in Ungauged Basins (PUB). The thesis presents the results of a process-based hydrological modelling study in the Congo Basin. One of the primary objectives of this study was to establish a hydrological model for the whole Congo Basin, using available historical data. The secondary objective of the study was to use the model and assess the impacts of future environmental change on water resources of the Congo Basin. Given the lack of adequate data on the basin physical characteristics, the preliminary work consisted of assessing available global datasets and building a database of the basin physical characteristics. The database was used for both assessing relationships of similarities between features of physiographic settings in the basin (Chapters 3 and 4), and establishing models that adequately represent the basin hydrology (Chapters 5, 6, and 7). The representative model of the Congo Basin hydrology was then used to assess the impacts of future environmental changes on water resources availability of the Congo Basin (Chapter 8). Through assessment of the physical characteristics of the basin, relationships of similarities were used to determine homogenous regions with regard to rainfall variability, physiographic settings, and hydrological responses. The first observation that comes from this study is that these three categories of regional groups of homogenous characteristics are sensible with regards to their geographical settings, but the overlap and apparent relationships between them are weak. An explanation of this observation is that there are insufficient data, particularly associated with defining sub-surface processes, and it is possible that additional data would have assisted in the discrimination of more homogenous groups and better links between the different datasets. The model application in this study consisted of two phases: model calibration, using a manual approach, and the application of a physically-based a priori parameter estimation approach. While the first approach was designed to assess the general applicability of the model and identify major errors with regard to input data and model structure, the second approach aimed to establish an understanding of the processes and identify useful relationships between the model parameters and the variations in real hydrological processes. The second approach was also designed to quantify the sensitivity of the model outputs to the parameters of the model and to encompass information sharing between the basin physical characteristics and quantifying the parameters of the model. Collectively, the study’s findings show that these two approaches work well and are appropriate to represent the real hydrological processes of Congo Basin. The secondary objective of this study was achieved by forcing the hydrological model developed for the Congo Basin with downscaled Global Climate Model (GCMs) data in order to assess scenarios of change and future possible impacts on water resources availability within the basin. The results provide useful lessons in terms of basin-wide adaptation measures to future climates. The lessons suggest that there is a risk of developing inappropriate adaptation measures to future climate change based on large scale hydrological response, as the response at small scales shows a completely different picture from that which is based on large scale predictions. While the study has concluded that the application of the hydrological model has been successful and can be used with some degree of confidence for enhanced decision making, there remain a number of uncertainties and opportunities to improve the methods used for water resources assessment within the basin. The focus of future activities from the perspective of practical application should be on improved access to data collection to increase confidence in model predictions, on dissemination of the knowledge generated by this study, and on training in the use of the developed water resources assessment techniques.
- Full Text:
Identification of novel marine algal compounds with differential anti-cancer activity: towards a cancer stem-cell specific chemotherapy
- Authors: De la Mare, Jo-Anne
- Date: 2012
- Subjects: Breast -- Cancer , Stem cells -- Research , Chemotherapy , Algae -- Biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4143 , http://hdl.handle.net/10962/d1016250
- Description: Breast cancer remains the leading cause of cancer-related death in women worldwide. Furthermore, it has been demonstrated that the treatment-resistant ER-PR-HER2/neu- sub-type is more common among women of African descent, necessitating the search for novel chemotherapies for this form of the disease. The secondary metabolites produced by marine algae represent a rich source of structurally unique compounds with chemotherapeutic potential, particularly in South Africa, whose oceans allegedly host 15 % of the total number of species in the world. Indeed, a recent study reported the isolation of a range of novel compounds from South African red and brown algae of the Plocamium, Portiera and Sargassum genera which displayed cytotoxicity against oesophageal cancer cells in vitro. The molecular mechanisms mediating this toxicity were unknown, as was the effect of these and similar compounds on metastatic ER-PR-HER2/neu- breast cancer cell lines or breast cancer stem cells. The current study aimed to address these questions by screening a library of twenty-two novel marine algal compounds for the ability to inhibit MDA-MB-231 and Hs578T breast cancer cells, while having no adverse effects on non-cancerous MCF12A breast epithelial cells. While twelve of these were toxic in the micromolar range against breast cancer cells, only the polyhalogenated monoterpenes RU004 and RU007, and the tetraprenylated quinone sargaquinoic acid (SQA) were identified as hit compounds based on the criteria that their cytotoxicity was specific to breast cancer and not healthy breast cells in vitro. On the other hand, the halogenated monoterpene RU015 was found to be highly toxic to both breast cancer and non-cancerous breast cell lines, while the halogenated monoterpene stereoisomers RU017 and RU018 were non-toxic to either of these cell lines. The mode of action of RU004, RU007, RU015 and SQA, together with the previously characterized carotenoid fucoxanthin (FXN), was assessed in terms of the type of cell death induced and the effect on cell cycle distribution of these compounds. Flow cytometric analysis of the extent of Hoescht 33342 and propidium iodide staining along with PARP cleavage studies suggested that SQA induced apoptosis in MDA-MB-231 cells. On the other hand, the highly toxic compound RU015 appeared to induce necrosis as evidenced by 50 kDa PARP cleavage product in MDA-MB-231 cells. The flow cytometry profiles of MDA-MB-231 and Hst578T cells treated with the hit compounds RU004 and RU007 were suggestive of the induction of apoptosis by these compounds. Cell cycle analysis by flow cytometry with propidium iodide staining revealed that both SQA and FXN induced G0-G1 arrest together with an increase in the apoptotic sub-G0 population, which agreed with previous reports in the literature. The molecular mechanism of action of SQA and FXN were further investigated by the identification of specific signal transducer molecules involved in mediating their anti-cancer activities. SQA was found to require the activity of numerous caspases, including caspase-3, -6, -8, -9, -10 and -13, for its cytotoxicity and was demonstrated to decrease the level of the antiapoptotic protein Bcl-2. On the other hand, FXN was shown to require caspase-1, -2, -3, -9 and - 10 for its toxicity. This, together with the ability to decrease the levels of Bcl-2, pointed to the involvement of the intrinsic pathway in particular in mediating the activity of FXN. The screening of algal compounds against non-cancerous breast epithelial cells carried out in this study, together with the investigation into their mechanisms of action, represent one of the few reports in which characterization of algal metabolites goes beyond the initial cytotoxicity assays. Finally, in order to assess the potential anti-cancer stem cell activity of the marine algal compounds, a subset of these was screened using a mammosphere assay technique developed in this study. The cancer stem cell (CSC) theory proposes that cancers arise from and are maintained by a specific subpopulation of cells able to undergo asymmetric cell division and termed CSCs. These CSCs are capable of anchorage-independent growth in serum-free culture conditions, such as those in the mammosphere assay. Using this assay, the novel halogenated monoterpene stereoisomers RU017 and RU018 were demonstrated to possess putative anti- CSC activity as evidenced by their ability to completely eliminate mammosphere formation in vitro. Furthermore, since RU017 and RU018 were non-toxic to both breast cancer and healthy breast cells, it appeared that the activity of the compounds was potentially specific to the CSCs. The results require further validation, but represent the first report of selective anti-CSC activity.
- Full Text:
Identifying expansive learning opportunities to foster a more sustainable food economy: a case study of Rhodes University dining halls
- Authors: Agbedahin, Adesuwa Vanessa
- Date: 2012
- Subjects: Food supply -- Education (Higher) -- South Africa -- Case studies Food industry and trade -- Education (Higher) -- Standards -- South Africa -- Case studies Food service employees -- Education (Higher) -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1560 , http://hdl.handle.net/10962/d1003442
- Description: This is a one year half thesis. This research was conducted within the context of the food services sector of Higher Education Institution dining halls and in the midst of the rising global call for food resource management and food waste reduction. The main aim of this research therefore was to identify opportunities for learning and change for a more sustainable food economy, contributing to Education for Sustainable Production and Consumption, and by further implication, Education for Sustainable Development. To achieve this aim, I used Cultural Historical Activity Theory as theoretical and methodological framework; drawing on the second and the third generations of this theory. Implicated in the above research approach is the identification of expansive learning opportunities from the surfacing of ‘tensions’ and ‘contradictions’. In this case study of the Rhodes University Campus Food Services, such tensions and contradictions inhibiting a more sustainable food economy, involving food waste production were identified. To narrow the scope of the study, one dining hall formed the focus of the case, with a two phased research approach whereby one research question and three goals were developed for each phase. The former being the exploration phase and the latter being the initial stages of the expansive phase. Methods used in line with the methodological framework included ten individual interviews with food producers (staff members), nine focus group discussions with food consumers (students), observations of the dining hall activities which lasted for over a month and two ‘Change Laboratory Workshops’. Some of the findings of this research are that food wastage cannot be addressed and appropriately curtailed without an intensive consideration of all the stages of food economy. Multiple contradictions and sources of tensions embedded in the Food Services Sector constituted major causes of food waste. Additionally, the lack of substantial food waste related teaching and learning activities, the presence of disputed rules, institutional structure and traditional practices within the Food Services all exacerbated the tensions and contradictions. More so, prioritizing some of this identified contradictions and tensions hindering a more sustainable food economy and relegating some as unimportant or nonurgent is unproductive. Finally, the non-existence of facilitated deliberation, consultation, dialogue, collaboration between food producers and food consumers has been identified as an obstacle to learning and institutional change. Recommendations abound in re-orienting, re-educating, and re-informing the constituents of the food economy. Re-visiting and revising of rules and regulations guiding conduct of students and kitchen staff members in the RU dining halls, as well as revision of existing learning support materials and mediating tools in use is needed. Recognition and consideration of the concerns and interests of students and kitchen staff members are also needed. Finally, there is a need to continue to address the tensions and contradictions identified in this case study, to further the Expansive Learning Process if a more sustainable food economy at Rhodes University is to be established.
- Full Text:
Illustrated medicines information for HIV/AIDS patients: influence on adherence,self-efficacy and health outcomes
- Authors: Barford, Kirsty-Lee
- Date: 2012
- Subjects: AIDS (Disease) -- Treatment -- South Africa , HIV infections -- Treatment -- South Africa , AIDS (Disease) -- Patients -- South Africa , HIV-positive persons -- South Africa , AIDS (Disease) -- Study and teaching -- South Africa , Antiretroviral agents -- South Africa , Communication in medicine -- South Africa , Communication in public health -- South Africa
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:3863 , http://hdl.handle.net/10962/d1015678
- Description: South Africa has an estimated 920 000 patients on antiretrovirals (ARVs), the largest number of patients in any country. ARV therapy demands adherence levels in excess of 95% to avoid development of drug resistance, but adherence to ARV therapy is estimated to be only between 50% and 70%. Poor medication adherence is acknowledged as a major public health problem, reducing the effectiveness of therapy and promoting resistance to ARVs. More than two thirds of the South African population have marginal reading skills and this significantly influences a patient’s ability to read and understand health-related information. Patient education materials tailored for the South African population could be a useful aid in facilitating communication with patients and perhaps impact positively on their medicine-taking behaviour. This behaviour is influenced by patient knowledge, beliefs, attitudes and expectations and includes self-management, self-efficacy and adherence. Self-efficacy, which refers to patient confidence in the ability to self-manage medicine taking, is a key factor influencing adherence. This study aimed to develop illustrated patient information leaflets (PILs) and medicine labels for all first-line ARV regimens used in the public health sector in South Africa and, using a randomised control study design, to investigate the impact of these illustrated information materials on knowledge, medication-taking behaviours and health outcomes in HIV/AIDS patients taking ARVs. To achieve this aim, the objectives were to assess HIV/AIDS and ARV-related knowledge, as well as self-efficacy and adherence to ARV therapy; to assess the influence of demographic variables on knowledge, adherence and self-efficacy; to assess the influence of the information materials on knowledge, self-efficacy and adherence and to assess the association of knowledge with health outcomes. Medicine labels and PILs, both English and isiXhosa, were developed for ARV regimens 1a, 1b, 1c and 1d. The 8-item Morisky Medication Adherence Scale (MMAS-8) and HIV Treatment Adherence Self Efficacy Scale (HIV-ASES) instruments for measuring respectively adherence and self-efficacy, were modified to optimize clarity, simplicity and cultural acceptability and were translated into isiXhosa using a multi-stage translation-back translation. The questions and the rating scales, for both the MMAS and HIV-ASES, underwent preliminary qualitative evaluation in focus group discussions. Patients were recruited from local Grahamstown clinics. A pilot study to evaluate applicability of the instruments was conducted in 16 isiXhosa AIDS patients on ARVs and the results from this study informed further modifications to the instruments. One hundred and seventeen patients were recruited for the randomised control trial and were randomly allocated to either control group (who received standard care) or experimental group (who received standard care as well as pictogram medicine labels and the illustrated PIL). Interviews were conducted at baseline and at one, three and six months. Data were analysed statistically using the t-test, chi-squared test and ANOVA (Analysis of Variance) at a 5% level of significance. Correlations were determined using Pearson and Spearman rho correlations. Approval was obtained from Rhodes University Ethical Standards Committee, Settlers Hospital Ethics Committee and the Eastern Cape Department of Health. The results of this research showed that illustrated PILs and medicine labels enhanced understanding of HIV/AIDS and ARV information, resulting in a mean overall knowledge score in the experimental group of 96%, which was significantly higher than the 75% measured in the control group. Variable knowledge scores were measured in three areas: baseline knowledge of general HIV/AIDS-related information was good at 87%, whereas knowledge scores relating to ARV-related information (60%) and side-effects (52%) were lower. These scores improved significantly in the experimental group over the 4 interviews during the 6 month trial duration, whereas in the control group, they fluctuated only slightly around the original baseline score. There was no significant influence of gender on knowledge score, whereas health literacy, education level and age tested (at one and three months) had a significant influence on knowledge. Self-efficacy and adherence results were high, indicating that the patients have confidence in their ability to adhere to the ARV therapy and to practice optimal self-care. Age, gender and education, in most cases, significantly influenced self-efficacy, but were found to have no effect on adherence. The CD4 count improved over the trial duration which may have been influenced by a number of factors, including better knowledge of ARVs and improved adherence. No significant parametric correlation was found between knowledge score and change in CD4 count, however, Spearman's rho showed significance (rs=0.498; p=0.022). Both patients and healthcare providers were highly enthusiastic about the illustrated labels and PILs, and indicated their desire for such materials to be routinely available to public sector HIV/AIDS patients. The isiXhosa version of the PIL was preferred by all the patients. These simple, easy-to-read leaflets and illustrated medication labels were shown to increase understanding and knowledge of ARVs and HIV/AIDS in low-literate patients, and their availability in the first-language of the patients was central to making them a highly useful information source.
- Full Text:
Imidazole-functionalized polymer microspheres and fibers–useful materials for immobilization of oxovanadium (IV) catalysts
- Authors: Walmsley, Ryan S , Ogunlaja, Adeniyi S , Coombes, Matthew J , Chidawanyika, Wadzanai J U , Litwinski, Christian , Torto, Nelson , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/246041 , vital:51431 , xlink:href="https://doi.org/10.1039/C2JM15485D"
- Description: Both polymer microspheres and microfibers containing the imidazole functionality have been prepared and used to immobilize oxovanadium(IV). The average diameters and BET surface areas of the microspheres were 322 μm and 155 m2 g−1 while the fibers were 1.85 μm and 52 m2 g−1, respectively. XPS and microanalysis confirmed the incorporation of imidazole and vanadium in the polymeric materials. The catalytic activity of both materials was evaluated using the hydrogen peroxide facilitated oxidation of thioanisole. The microspheres were applied in a typical laboratory batch reactor set-up and quantitative conversions (>99%) were obtained in under 240 min with turn-over frequencies ranging from 21.89 to 265.53 h−1, depending on the quantity of catalyst and temperature. The microspherical catalysts also proved to be recyclable with no drop in activity being observed after three successive reactions. The vanadium functionalized fibers were applied in a pseudo continuous flow set-up. Factors influencing the overall conversion and product selectivity, including flow rate and catalyst quantity, were investigated. At flow rates of 1–4 mL h−1 near quantitative conversion was maintained over an extended period. Keeping the mass of catalyst constant (0.025 g) and varying the flow rate from 1–6 mL h−1 resulted in a shift in the formation of the oxidation product methyl phenyl sulfone from 60.1 to 18.6%.
- Full Text:
Implementation of environmental learning in the NSSC biology curriculum component: a case study of Namibia
- Authors: Tshiningayamwe, Sirkka Alina Nambashusan
- Date: 2012
- Subjects: Environmental education -- Namibia -- Case studies Environmental education -- Study and teaching (Secondary) -- Namibia -- Case studies Environmental education -- Evaluation -- Namibia -- Case studies Biology -- Study and teaching (Secondary) -- Namibia -- Case studies Biology -- Curricula
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1564 , http://hdl.handle.net/10962/d1003446
- Description: In the context of ecological crisis and environmental deterioration, teaching about environmental issues and the preservation of the world’s environment has become increasingly important across the globe (Chi-chung Ko & Chi-kin Lee, 2003). Of the various subjects taught in secondary schools, Science is often perceived as one that can make a significant contribution to environmental education. It is in this light that the study has looked at how Grade 11 and 12 Biology teachers in the Namibian context implement Environmental Learning (EL). This study was constituted as a case study of two schools in Windhoek, in the Khomas region. The study investigated the implementation of EL in the Biology curriculum focusing on the constraints and enabling factors influencing the implementation. This study employed qualitative methods, specifically semi-structured interviews, classroom observations and document analysis in its investigation of EL implementation. Purposive sampling was done and piloting of interview and observation schedules was used to refine the schedules. Ethical issues were taken into consideration throughout the study. The key findings from the study are as follows: - Teachers’ knowledge and interest in environmental education influence how teachers facilitate EL; - There is a mismatch between EL theories and practice; - Teaching of EL is mainly informed by the syllabus and not other curriculum documents, - Current assessment policy and practice impact on EL; and - Possibilities exist for improving EL in Namibia’s Biology curriculum. These key findings have been used to make recommendations for the study which are as follows: - Strengthen the subject content and interest of teachers; - There should be a match between EL theories and practice; - Reorient curriculum documents and other learning support materials used for EL; - Change in assessment approaches; and - Translate constraints of EL into enablers. The study concludes by calling for further research into EL pedagogies. This can be used to improve EL implementation in the region where the study was situated.
- Full Text:
Improving the quality and relevance of environmental learning through the use of a wider range of preferred teaching methods: a case of primary schools in Mufulira District in the Copperbelt Province in Zambia
- Authors: Kalumba, Evaristo
- Date: 2012
- Subjects: Environmental education -- Research -- Zambia Primary school teaching -- Research -- Zambia Primary school teaching -- Methodology -- Research Primary school teaching -- Standards -- Research
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1571 , http://hdl.handle.net/10962/d1003453
- Description: The study was conducted to investigate whether the use of a wider range of teaching methods can improve the quality of environmental learning in five Zambian primary schools. Nine teachers from five schools were involved in the preliminary stage of answering of questionnaires, interviews and focus group discussions about the use of dominant teaching methods and new teaching methods; while only four were involved in the observations of four lessons. The study is a contribution to the on‐going debate on the investigation of whether teaching methods used by teachers can be one of the factors that can influence the quality of education. Definitions of quality and educational quality in particular, are not easy to establish and no agreed upon framework for educational quality exists at present. This study reviews the debates on educational quality, and identifies three major paradigms or discourses on educational quality; and considers the human rights, social justice and capabilities approaches and educational quality frameworks as being relevant to environmental learning and education for sustainable development in the Southern African Development Community context. This, together with a review of research on teaching methods in environmental education, provides the theoretical framework for this study. Using action research and an interpretative methodological framework, a series of research activities were undertaken to generate research data because the study was investigating the teachers’ practice with a view to probe change and to analyse the findings. Nine teachers participated in the preliminary stage of answering questionnaires and focus group interviews reflecting on existing teaching methods. In stage two of this study, teachers went through a planning workshop during which they planned lessons using new preferred teaching methods. The third stage was lesson observations of planned lessons. The final stage was the reflection workshop during which the teachers shared their experiences with the use of new teaching methods. The teaching practices of teachers using the new teaching methods were the subject of further analysis. In order to find out how the use of a wide range of teaching methods can improve quality of environmental learning in primary schools nine teachers were observed teaching lessons with new teaching methods. The Nikel and Lowe (2010) fabric of dimensions of educational quality was adapted and used to find out if teachers included dimensions of quality in the teaching process. Additional socio‐cultural and structural quality dimensions, identified through a review of southern African research, were used to find out if teachers included contextualized regional dimensions of educational quality. This was done to investigate whether the process of teaching and learning was relevant to the learners. Teachers involved in the research reflected that when they used a wider range of teaching methods the result was that the learning opportunities for learners were enhanced and that the methods added value to their teaching, improving the quality of their teaching. The use of a wider range of teaching methods showed the presence of several indicators of dimensions of educational quality, as reflected in the quality analysis tool. Teachers indicated that the use of a wider range of teaching methods led them to include the socio‐cultural dimensions such as the use of local languages and structural dimensions such as informal seating arrangements or group work that they would otherwise neglect if they used the traditional narrow range of teaching methods. A wider range of teaching methods provided learners with an enjoyable learning atmosphere during the lesson. The research also identified that this study can be taken further through broader observations, and that the educational quality dimensions tool is useful for different levels of the education system, and that it has potentially productive uses in teacher education, particularly for observations during teaching practice.
- Full Text:
In silico characterisation of the four canonical plasmodium falciparum 70 kDa heat shock proteins
- Authors: Hatherley, Rowan
- Date: 2012
- Subjects: Heat shock proteins -- Research , Plasmodium falciparum -- Research , Plasmodium -- Research , Endoplasmic reticulum , Cytosol , Mitochondria -- Formation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4026 , http://hdl.handle.net/10962/d1004086 , Heat shock proteins -- Research , Plasmodium falciparum -- Research , Plasmodium -- Research , Endoplasmic reticulum , Cytosol , Mitochondria -- Formation
- Description: The 70 kDa heat shock proteins expressed by Plasmodium falciparum (PfHsp70s) are believed to be essential to both the survival and virulence of the malaria parasite. A total of six Hsp70 genes have been identified in the genome of P. falciparum. However, only four of these encode canonical Hsp70s, which are believed to localise predominantly in the cytosol (PfHsp70-1 and PfHsp70-x), the endoplasmic reticulum (PfHsp70-2) and mitochondria (PfHsp70-3) of the parasite. These proteins bind and release peptide substrates in an ATP-dependent manner, with the aid of a J-domain protein cochaperone and a nucleotide exchange factor (NEF). The aim of this study was to identify the residues involved in the interaction of these PfHsp70s with their peptide substrates, their J-domain cochaperones and potential NEFs. These residues were then mapped to three-dimensional (3D) structures of the proteins, modelled in three different conformations; each representing a different stage in the ATPase cycle. Additionally, these proteins were compared to different types of Hsp70s from a variety of different organisms and sequence features found to be specific to each PfHsp70 were mapped to their 3D structures. Finally, a novel modelling method was suggested, in which the structures of templates were remodelled to improve their quality before they were used in the homology modelling process. Based on the analysis of residues involved in interactions with other proteins, it was revealed that each PfHsp70 displayed features that were specific to its cellular localisation and each type of Hsp70 was predicted to interact with a different set of NEFs. The study of conserved features in each PfHsp70 revealed that PfHsp70-x displayed various sequence features atypical of both Plasmodium cytosolic Hsp70s and cytosolic Hsp70s in general. Additionally, residues conserved specifically in Hsp70s of Apicomplexa, Plasmodium and P. falciparum were identified and mapped to the each PfHsp70 model. Although these residues were too numerous to reveal any information of specific value, these models may be useful for the purposes of aiding the design of drug compounds against each PfHsp70. Finally, the novel modelling approach did show some promise. Half of the models produced using the modified templates were of a higher quality than their counterparts modelled using the original templates. This approach does still require a lot of validation work and statistical evaluation. It is hoped that it could prove to be a useful approach to homology modelling when the only templates available are poor quality structures.
- Full Text:
In vitro dissolution kinetics of Captopril from microspheres manufactured by solvent evaporation
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: vital:6390 , http://hdl.handle.net/10962/d1006311
- Description: The aim of this study was to develop and assess captopril-loaded microspheres in which Methocel and Eudragit RS were used as release-controlling factors and to evaluate captopril (CPT) release using kinetic models. Drug-excipient interactions were evaluated using infrared studies, and the physical appearance was characterized using scanning electron microscopy (SEM). A burst effect was observed during the first stage of dissolution for most batches of microspheres. SEM results reveal that this may be attributed to dissolution of captopril crystals that were present on the surface, embedded in the superficial layer of the matrix materials, trapped near the surface of the microspheres, or that may have diffused rapidly through the porous surface of the capsules. The release data generated during in vitro release studies were fitted to zero-order, first-order, Higuchi, Korsmeyer–Peppas, Kopcha, and Makoid–Banakar models. The release kinetics of captopril from most formulations followed a classical Fickian diffusion mechanism. SEM photographs showed that diffusion took place through pores located in the surface of the microcapsules. The Kopcha model diffusion and erosion terms showed a predominance of diffusion relative to swelling or erosion throughout the entire test period. The drug release mechanism was also confirmed by the Makoid–Banakar and Korsmeyer–Peppas model exponents. This further supports a diffusion–release mechanism for most formulations. The models postulate that the total drug released is a summation of several mechanisms (viz., burst release, relaxation-induced controlled release, and diffusional release). These results also support the potential application of Eudragit/Methocel microspheres as a suitable sustained-release drug delivery system for captopril.
- Full Text:
In vitro photodynamic effect of aluminum tetrasulfophthalocyanines on melanoma skin cancer and healthy normal skin cells
- Authors: Maduray, Kaminee , Odhay, Bharti , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245762 , vital:51403 , xlink:href="https://doi.org/10.1016/j.pdpdt.2011.07.001"
- Description: Photodynamic therapy is a medical treatment that uses an inactive dye/drug and lasers as a light source to activate the dye/drug to produce a toxic form of oxygen that destroys the cancer cells. This study aimed at investigating the cytotoxic effects of different concentrations of aluminum tetrasulfophthalocyanines in its inactive and active state (laser induced) on melanoma skin cancer cells, healthy normal skin fibroblast and keratinocyte cells. Experimentally, 3 x 10(4) cells/ml were seeded in 24-well plates before treatment with different concentrations of aluminum tetrasulfophthalocyanines. After 2 h, cells were irradiated with a light dose of 4.5 J/cm(2). Post-irradiated cells were incubated for 24 h before cell viability was measured using the CellTiter-Blue Viability Assay. Results showed that aluminum tetrasulfophthalocyanines at high concentrations were cytotoxic to melanoma cells in the absence of laser activation. In the presence of laser activation of aluminum tetrasulfophthalocyanines at a concentration of 40 mu g/ml decreased cell viability of melanoma cells to 45%, fibroblasts to 78% and keratinocytes to 73%. At this photosensitizing concentration of aluminum tetrasulfophthalocyanines the efficacy of the treatment light dose 4.5 J/cm(2) and the cell death mechanism induced by photoactivated aluminum tetrasulfophthalocyanines was evaluated. A light dose of 4.5 J/cm(2) was more efficient in killing a higher number of melanoma cells and a lower number of fibroblast and keratinocyte cells than the other light doses of 2.5 J/cm(2), 7.5 J/cm(2) and 10.5 J/cm(2). Apoptosis features such as blebbing, nucleus condensation, nucleus fragmentation and the formation of apoptotic bodies were seen in the photodynamic therapy treated melanoma skin cancer cells. This in vitro photodynamic therapy study concludes that using aluminum tetrasulfophthalocyanines at a photosensitizing concentration of 40 mu g/ml in combination with a laser dose of 4.5 J/cm(2) was potentially lethal for melanoma skin cancer cells and less harmful for the normal healthy skin cells. (c) 2011 Elsevier B.V. All rights reserved.
- Full Text: