Exploring the suitability of causal loop diagrams to assess the value chains of aquatic ecosystem services: a case study of the Baviaanskloof, South Africa
- Authors: Rawlins, Jonathan Mark
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4909 , vital:20742
- Description: Healthy, functioning aquatic ecosystems are fundamental to the survival and development of any nation, particularly so for water-stressed countries like South Africa. Aquatic ecosystem services (AESs) are becoming increasingly recognised for their importance to society with regards to the ecological goods and services they provide in terms of health, social, cultural and economic benefits. The development of markets for AESs begins with a clear understanding of the nature and extent of the goods and services provided by aquatic ecosystems. However, an inclusive understanding of AESs and their associated values is currently lacking in South Africa. Although flows of ecosystem services provide a nearly limitless set of valuable properties, a large proportion of their services remain unpriced or inaccurately priced through traditional neo-classical markets. This often results in market failure, as these markets do not reflect the full social costs and/or benefits of ecosystem services. This provides incentive to identify and develop a tool to bridge the gap between ecosystem service valuation and practical, sustainable management recommendations for improving the provision of ecosystem services and their associated markets. This study explores the suitability of causal loop diagrams (CLDs) to assess the value chains of AESs in South Africa within the context of a case study. AESs do not usually have finite market values nor are they traded in formal markets, thus, a traditional approach to value chain analysis is unsuitable. A professional workshop environment was utilised to facilitate a transdisciplinary approach towards identifying relevant AESs and their complex inputs, interactions and trade-offs. Numerous CLDs were developed in an effort to map the complex relationships between these AESs and their associated inputs, which formed the basis to attempt subsequent scenario analyses and 'alternative' value chain analyses. The findings of this study show that CLDs have the potential to qualitatively identify challenges and opportunities within the value chains of AESs. Thus, the use of such 'alternative' value chain analyses can directly contribute towards the development of recommendations for improving sustainable management of aquatic ecosystems.
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Exploring transformative social learning and sustainability in community based irrigation scheme contexts in Mozambique
- Authors: Baloi, Aristides
- Date: 2017
- Subjects: Social learning -- Mozambique , Irrigation -- Social aspects -- Mozambique , Water resources development -- Mozambique , Sustainable agriculture -- Mozambique , Community development -- Mozambique
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/50154 , vital:25963
- Description: This study set out to examine transformative social learning and sustainability in the context of community-based irrigation systems in Mozambique. These irrigation systems are socio-ecological in nature. The history of irrigation systems in Mozambique can be described in two periods: pre-Independence period (mainly the colonial period) and the post-Independence period from 1975 onwards. Most recently, the Mozambique Government has introduced a policy which supports community-based irrigation system implementation and management via irrigation associations in a move to support a shift from rain-fed farming practices to irrigation-supported farming practices amongst smallholder farmers. It is this shift in the object of activity that this study focusses on. It does this by studying learning process in the constituted irrigation associations, examining whether such learning is transformative and sustainability oriented or not, and how such learning can be further expanded and supported. Learning may occur in socio-ecological systems, but whether that learning enables transformation and sustainability of irrigation systems and the constituted associations is as yet under-explored in the Mozambique context and in the context of Education for Sustainable Development in southern Africa. The aim of this research was therefore to understand transformative social learning within the development of sustainable irrigation practices in the context of irrigation associations and new agrarian policy development in Mozambique. To examine transformative social learning in sustainable irrigation system practices (including management practices), the study worked with three research goals, which also formed phases of the study’s design: GOAL 1: Examine how and what transformative social learning has (or has not) emerged in existing activity systems to date (Phase 1: Activity System Analysis). GOAL 2: Examine how transformative social learning could emerge through expansive learning processes (Phase 2: Identification of contradictions and new solution modelling through Developmental Work Research and Change Laboratories). GOAL 3: Identify what opportunities exist for ongoing transformative social learning (Phase 3: Identification of absences and ongoing dialectical transformation possibilities). The study draws on theories of Social Learning, Transformative Learning and Cultural Historical Activity Theory’s (CHAT) expansive learning and formative interventionist research framework to develop insights into the learning processes. It works especially with third generation Cultural Historical Activity Theory which provides a theory of expansive social learning and collective transformative agency formation, which I deemed most appropriate for the need to understand the transformation of farmers’ activities in a collective formation such as an irrigation association. The study involved identification and examination of interacting activity systems, contradictions or dissonances in two case studies of community-based irrigation system development via the respective associations. It involved identifying existing learning, as well as engaging in formative intervention research to expand learning in two case study sites: namely the Macubulane and Massaca Irrigation Associations, located near Maputo, Mozambique in the Inkomati and Umbeluzi river basins. The Macubulane community practices a monocropping system of sugar cane plantations using sprinkler irrigation methods and the Massaca community practices a mixed cropping system growing vegetables using mainly gravity or furrow irrigation methods. The study uses a qualitative research approach and is underlaboured by Dialectical Critical Realism which allowed for a deeper probing of ontology and transformative praxis, and transformative learning. The study used methods which included in-depth interviews, change laboratory workshops, document analysis and focus group interviews with farmers and subjects in associated activity systems. Analysis involved activity system analysis, identification of contradictions, modeling of solutions, transformative agency analysis, as well as analysis of real and nominal absences and generative mechanisms as recommended in dialectical critical realism. I used inductive, abductive and retroductive modes of inference, relying on the latter to identify further potential for transformative learning. The study demonstrates that within the associations, transformative social learning is taking place as farmers seek to address problems and contradictions. This learning leads to the creation of new agency and capabilities by ensuring good yields and continuous improvement of management practices and social status. Learning operates through formal mediation in the irrigation system of workplace-based operation, maintenance and crop management practices (i.e. through workplace learning). Social learning occurs through collective engagement with the constraints that the association faces while applying new knowledge, introducing new technology, in the process of administration and planning of irrigation activities. Expansive learning is possible when mediated actively through formative interventions in change laboratory workshops. All three types of learning were found to be present and possible in the context of the two irrigation scheme contexts. The main study findings are that transformative social learning is a collective object-driven process in the context of a transforming object (from rain-fed to sustainable community-based irrigation scheme farming in this study), that can be explained from the level of generative mechanisms and associated real absences that shape nominal absences and contradictions within and between activity systems. These induce, and have potential to induce, transformative learning in irrigation systems, including the emergence of transformative agency via learning through workplace-based, wider social learning, and expansive learning interaction processes amongst subjects in interacting activity systems. Absenting absences is also crucial for extending the potential of transformative learning in irrigation associations. The study further shows how critical realism helps to interpret learning processes and how it strengthens the empirical findings obtained from qualitative analysis. A key outcome of the study is a model that frames conceptualisation of transformative social learning in irrigation systems. The model and the insights gained into farmers learning around the transformation of the object of activity explored in this study have implications for wider curriculum and policy development interventions. The study therefore also makes recommendations for curriculum development and policy implementation intervention. The curriculum development recommendations are not at the level of making recommendations for new courses only, but frame how the design of new courses should take into account the wider processes of learning and change associated with the transformation of an object of activity as articulated in the study. It recommends an approach that allows for in-field engagement with contradictions and the absenting of absences (a problem-based type of curriculum) that will also allow for conceptual development and understanding of the changing object of activity (i.e. community-based irrigation scheme practice and management). The main policy recommendation made from the study is to invest more in farmer support and farmers’ learning so that they can transition from rain-fed agriculture to sustainable irrigation scheme development and management via their associations. The research contributes to knowledge production on irrigation practices; considering that substantial understandings were generated through analysis of communal irrigation scheme practice and management and its implications, especially from a transformative learning perspective. As shown in this study, transformative social learning theories are still not well understood in the context of irrigation system development, and this study has contributed knowledge to this field. The study contributes towards understanding of sustainability learning in irrigation associations in terms of concepts and practices. The study offers a model for transformative social learning in irrigation scheme development and suggests an expanded curriculum for community-based irrigation association practice and management. Overall, the study contributes to an understanding of transformative, sustainability oriented learning processes as support for the emergence of community-based irrigation associations. Additionally, the study has added perspectives on how to frame transformative social learning from a CHAT and critical realist perspective in Education for Sustainable Development. The study also contributes to a growing body of scholarship in southern Africa which seeks to develop expansive, transformative social learning approaches in response to concerns experienced by communities who are reliant on natural resources and the environment for their livelihoods and well-being, and who are also seeking to emerge out of poverty.
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Exports, capital formation and economic growth in South Africa
- Authors: Feddersen, Maura , Nel, Hugo , Botha, Ferdi
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396035 , vital:69145 , xlink:href="https://www.ajol.info/index.php/aref/article/view/162150"
- Description: In South Africa the export sector is frequently accorded a special role in encouraging faster economic growth. Nonetheless, a question that remains unresolved is whether higher export growth indeed leads to higher economic growth and what particular role exports may play within the overall economic growth process of the country. This study applies Johansen’s cointegration procedure, impulse response functions, variance decomposition analysis and Granger causality tests to shed light on the channels through which export growth may impact South Africa’s economic growth rate. Quarterly time series data ranging from 1975q1 to 2012q4 is employed in the study’s empirical tests. The results support the notion that the role of exports lies in their ability to encourage investment and capital formation. While export growth directly supports higher economic growth in the short-run, the long-term effect was found to lie in supporting faster capital formation, and in turn, significantly increasing economic growth. Overall, a strategy of export-led growth that does not explicitly emphasize the export-capital-growth connection is likely to fall short of reflecting the dynamics contained within the exports-growth relationship in South Africa.
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Extended use of grey water for irrigating home gardens in an arid environment
- Authors: Al-Ismaili, Abdulrahim M , Ahmed, Mushtaque , Al-Busaidi, Ahmed , Al-Adawi, Seif , Tandlich, Roman , Al-Amri, Mohammed
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76048 , vital:30497 , https://doi.org/10.1007/s11356-017-8963-z
- Description: The use of treated grey water (GW) for home gardens, peri-urban agriculture and landscaping is becoming popular in many water stressed countries such as Oman. This study aims to investigate the treatment efficacy, health and chemical concerns, cost-benefits and maintenance protocol of a GW treatment system as well as the effect of irrigation with GW on crop yield. Therefore, a decentralized homemade GW treatment system was installed in a newly constructed house in Muscat, Oman and studied over a 2-year period. The treated GW was found to be suitable for irrigation as per Omani standards. GW when mixed with kitchen effluent substituted the use of nutrient supplements for plants and did not show any harmful chemical or biological contamination. The capital cost of the system was around US $980, and the annual operating cost was US $78 with annual income and savings from the system being around US $572 indicating a payback period of nearly 2 years. It was found that the system required simple but regular maintenance particularly cleaning of the top layer of the filter. It can be concluded from this study that such a GW system should be technically, economically and environmentally feasible in Oman. Also, wider acceptance by the general public to the idea of GW reuse will help in mitigating the water shortage problem of the country to some extent.
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Extracellular Hsp90 and TGFP regulate adhesion, migration and anchorage independent growth in a paired colon cancer cell line model
- Authors: de la Mare, Jo-Anne , Jurgens, Tamarin , Edkins, Adrienne L
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59920 , vital:27710 , https://doi.org/10.1186/s12885-017-3190-z
- Description: Tumour metastasis remains the major cause of death in cancer patients and, to date, the mechanism and signalling pathways governing this process are not completely understood. The TGF-ß pathway is the most commonly mutated pathway in cancer, however its role in cancer progression is controversial as it can function as both a promoter and a suppressor of metastasis. Although previous studies have suggested a role for the molecular chaperone Hsp90 in regulating the TGF-ß pathway, the level at which this occurs as well as the consequences in terms of colon cancer metastasis are unknown.
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Facile synthesis of glutathione-l-Cysteine co-capped CdTe core shell system
- Authors: Daramola, Olamide A , Siwe-Noundou, Xavier , Krause, Rui W M , Marks, John A
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/195003 , vital:45518 , xlink:href="https://doi.org/10.1166/jnn.2017.13823"
- Description: Semiconductor nanoparticles also known as quantum dots (QDs) have been used in diverse areas of application due to their good optical and photo-physical properties. The synthesis of core–shell QDs have assisted to improve the stability of most nano-particles but the size and long term stability of such materials have been problematic. However, thiol-capped CdTe QDs have been regarded as some of the most widely synthesized nanoparticles due to their unique optical properties. The use of un-stable tellurium source such as NaHTe or highly toxic H2Te gas makes the reaction condition cumbersome. In this study, we prepared some CdTe QDs and core–shell QDs using K2TeO3 as a stable source of tellurium without inert gas protection. This was done using a co-capped bio-compatible coating such as cysteine and glutathione following a modified standard method to produce QDs in the yields of about 60 to 80%. All the synthesized materials were subsequently characterized using various characterization techniques. The systematic optimization of the reaction parameters such as reaction time, pH and mole ratio results with a drastic red shift in wavelength (546–600 nm) by the CdTe core proved that an extra material has been deposited unto the surface of the CdTe core. The 60 days stability test conducted demonstrated that the core–shell nanoparticles were quite stable. Since this reaction was performed under open air conditions and no special ligand or buffer solution was used, it may suitably be applied on an industrial scale.
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Factors affecting the implementation of the Water Services Provision (WSP) strategy at Amathole District Municipality (ADM)
- Authors: Snombo, Kanyisa
- Date: 2017
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/5533 , vital:20939
- Description: Amathole District Municipality (ADM) in the Eastern Cape province of South Africa changed its water service provision strategy in 2012 from decentralized to a centralized strategy as a way of trying to improve its water service delivery. Since this change, no study has been done to explore how the centralized water service strategy has so far been implemented at ADM. The aim of this exploratory qualitative study was to describe how ADM implemented its centralized water strategy and also assess the extent of alignment of strategy execution using Higgins’ (2005) 8 “S” model. Purposively, a total of five senior managers were identified and interviewed in East London as they were intimately involved in the daily operation of the water service provision over the years. Data gathered through audio recorded, in-depth and semi-structured interviews with each of the senior managers and also documented reports on Water Service Provision (WSP) were analyzed using thematic analysis into meaningful patterns reflecting each of the components of Higgins’ (2005) 8 “S” model. Findings of this qualitative study reveal that senior managers had different but complementary views of what strategy they were implementing at ADM. More importantly, the implementation of centralized water services provision model by ADM was characterized by deep and persistent vacancies of key technical but also managerial positions in the new structure. Furthermore while human and financial resources were inadequate to match with the depth and variety of changes necessary to have the requisite number of staff, ADM implemented the centralized water service strategy with poor skills mix which negatively impacted on quality of water service. While ADM had ten espoused shared values, none of these were commonly and widely shared by employees in their day-to-day world of work. Instead, employee’s behavior at ADM was practically shaped by the emergent values of cooperation, and employee care and recognition. Thus there was misalignment between espoused and practiced shared values. Furthermore there was also recurrent and deep misalignment between structure, staff, resources and water quality systems which compounded the difficulties experienced by ADM in pursuit of centralized water service provision. While the use of outsourced mechanical and electrical services was a remedy to staff shortages and the lack of skills mix, it ultimately further aggravated the financial challenges of ADM by draining more of the already limited financial resources. Recommendations for improving the implementation of centralized water service strategy and areas for further research are suggested.
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Fibronectin is a stress responsive gene regulated by HSF1 in response to geldanamycin
- Authors: Dhanani, Karim C H , Samson, William J , Edkins, Adrienne L
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59931 , vital:27711 , https://doi:10.1038/s41598-017-18061-y
- Description: Fibronectin is an extracellular matrix glycoprotein with key roles in cell adhesion and migration. Hsp90 binds directly to fibronectin and Hsp90 depletion regulates fibronectin matrix stability. Where inhibition of Hsp90 with a C-terminal inhibitor, novobiocin, reduced the fibronectin matrix, treatment with an N-terminal inhibitor, geldanamycin, increased fibronectin levels. Geldanamycin treatment induced a stress response and a strong dose and time dependent increase in fibronectin mRNA via activation of the fibronectin promoter. Three putative heat shock elements (HSEs) were identified in the fibronectin promoter. Loss of two of these HSEs reduced both basal and geldanamycin-induced promoter activity, as did inhibition of the stress-responsive transcription factor HSF1. Binding of HSF1 to one of the putative HSE was confirmed by ChIP under basal conditions, and occupancy shown to increase with geldanamycin treatment. These data support the hypothesis that fibronectin is stress-responsive and a functional HSF1 target gene. COLA42 and LAMB3 mRNA levels were also increased with geldanamycin indicating that regulation of extracellular matrix (ECM) genes by HSF1 may be a wider phenomenon. Taken together, these data have implications for our understanding of ECM dynamics in stress-related diseases in which HSF1 is activated, and where the clinical application of N-terminal Hsp90 inhibitors is intended.
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Figuring maternity: Christine Dixie's Parturient Prospects
- Authors: Schmahmann, Brenda
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147748 , vital:38667 , https://doi.org/10.1080/00043389.2007.11877068
- Description: The Interior, Birthing Tray and Parturition are three sub-sections of a project entitled Parturient Prospects that artist Christine Dixie began in 2005, when she was pregnant with her second child, and completed by the end of 2006. In Parturient Prospects, the author reveals, Dixie situates her experiences against Western discourses, especially images from early modern Europe. Focusing on the ways in which visual representations construct woman as ‘other’, Dixie invokes reference to not only representations of birth and maternity but also religious, medical and geographical images.
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First example of nonlinear optical materials based on nanoconjugates of sandwich phthalocyanines with quantum dots
- Authors: Oluwole, David O , Yagodin, Alexey V , Mkhize, Nhlakanipho C , Sekhosana, Kutloana E , Martynov, Alexander G , Gorbunova, Yulia G , Tsivadze, Aslan Yu , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/238014 , vital:50577 , xlink:href="https://doi.org/10.1002/chem.201604401"
- Description: We report original, selective, and efficient approaches to novel nonlinear optical (NLO) materials, namely homoleptic double- and triple-decker europium(III) complexes 2 and 3 with the A3B-type phthalocyanine ligand (2,3-bis[2′-(2′′-hydroxyethoxy)ethoxy]-9,10,16,17,23,24-hexa-n-butoxyphthalocyanine 1) bearing two anchoring diethyleneglycol chains terminated with OH groups. Their covalently linked nanoconjugates with mercaptosuccinic acid-capped ternary CdSeTe/CdTeS/ZnSeS quantum dots are prepared in the presence of an ethyl(dimethylaminopropyl)carbodiimide activating agent. Optical limiting (OL) properties of the obtained low-symmetry complexes and their conjugates with quantum dots (QDs) are measured for the first time by the open-aperture Z-scan technique (532 nm laser and pulse rate of 10 ns). For comparison, symmetrical double- and triple-decker EuIII octa-n-butoxyphthalocyaninates 5 and 6 and their mixtures with trioctylphosphine oxide-capped QDs are also synthesized and studied. It is revealed that both lowering of molecular symmetry and expansion of the π-electron system upon moving from double- to triple-decker complexes significantly improves the OL characteristics, making the low-symmetry triple-decker complex 3 the most efficient optical limiter in the studied family of sandwich complexes, affording 50 % lowering of light transmittance below 0.5 J cm−2 input fluence. Conjugation (both covalent and noncovalent) with QDs affords further enhancement of the OL properties of both double- and triple-decker complexes. Altogether, the obtained results contribute to the development of novel nonlinear optical materials for future nanoelectronic and optical device applications.
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Flexible Metal–Porphyrin Dimers (M= MnIIICl, CoII, NiII, CuII)
- Authors: Li, Minzhi , Zhang, Qian , Xu, Li , Zhu, Weihua , Mack, John , May, Aviwe K , Nyokong, Tebello , Kobayashi, Nagao , Liang, Xu
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239676 , vital:50754 , xlink:href="https://doi.org/10.1002/cplu.201600475"
- Description: Four metalloporphyrin dimers linked by bridging amide-bonded xanthene moieties and that contain either MnIII, CoII, NiII, or CuII metal centers were synthesized. Various spectroscopic, electrochemical, and spectroelectrochemical methods were used to study trends in their properties. Their electronic structure and optical properties were analyzed through a comparison of the electronic absorption and magnetic circular dichroism (MCD) spectral data with the results of time-dependent (TD)-DFT calculations.
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Fluorescence behaviour of supramolecular hybrids containing graphene quantum dots and pyrene-derivatized phthalocyanines and porphyrins
- Authors: Achadu, Ojodomo John , Managa, Muthumuni , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188953 , vital:44801 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.10.029"
- Description: Novel pyrene-derivatized zinc and cobalt phthalocyanines (Pcs) and porphyrins (Ps) were immobilized on graphene quantum dots (GQDs) to form GQDs-Pcs and GQDs-Ps supramolecular hybrids via the π–π stacking interaction method. Spectroscopic evidence shows that the resultant hybrids were stable owing to the strong π–π stacking interaction between the GQDs and the respective Pcs and Ps, thus leading to the fabrication of interesting and functional supramolecular hybrids by taking advantage of the delocalized π electron systems of GQDs and the macrocycles. The conjugates showed increased fluorescence quantum yields for the Pcs/Ps, but decreased values for the GQDs in the conjugates. These novel hybrid materials could potentially be deployed for studies in both fundamental and applied perspectives due to the synergistic contributions resulting from the combination of their excellent electronic and optical properties.
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Forensic entomotoxicology revisited: towards professional standardisation of study designs
- Authors: da Silva, Erica I T , Wilhelmi, Brendan S , Villet, Martin H
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140819 , vital:37921 , DOI: 10.1007/s00414-017-1603-9
- Description: Forensic entomotoxicology is the use of insects as evidence of whether a toxicant is present in an environment such as a corpse, river or landscape. The earliest overtly forensic study was published in 1977, and since then, at least 63 papers have been published, most of them focused on the detection of toxicants in insects or on effects of toxicants on diverse insect indicator taxa. A comprehensive review of the published literature revealed various inconsistencies between studies that could be addressed by introducing standard protocols for such studies. These protocols could include selecting widespread and common model organisms (such as Lucilia sericata, Calliphora vicina, Chrysomya megacephala and Dermestes maculatus) and model toxicants (e.g. morphine and amitriptyline) to build up comparative databases; developing a standard matrix for use as a feeding substrate; setting guidelines for statistically adequate sample sizes; and deploying more sophisticated analytical methods from the general field of toxicology.
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Forest degradation and invasive species synergistically impact Mimusops andongensis (Sapotaceae) in Lama Forest Reserve, Benin
- Authors: Sinasson, Gisèle K , Shackleton, Charlie M , Glèlè Kakaï, Romain L , Sinsin, Brice
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182038 , vital:43792 , xlink:href="https://doi.org/10.1111/btp.12370"
- Description: Harvesting of Non-Timber Forest Products (NTFPs) can threaten target species, especially those with limited distribution and density. Exploited species also face threats from habitat fragmentation, fire, and invasive species. We assessed the impact of human disturbances and invasive species on the population of a key multipurpose NTFP species, Mimusops andongensis, in Lama Forest reserve (Benin). The densities of adult trees and regenerative stems decreased with increasing degradation. Mimusops andongensis contributed less to total tree density with increasing human disturbance. There were significantly fewer M. andongensis recruits with increasing cover of invasive Chromolaena odorata. Smaller diameter individuals predominated in non-degraded and moderately degraded sites while in degraded sites, the structure showed a negative exponential trend with the density of small diameter individuals being less than two trees/ha. Larger individuals were also rare in degraded sites. The low density of both mature trees and seedlings in degraded sites may undermine the long-term viability of M. andongensis, despite existing protection against NTFP harvesting and other anthropogenic pressures. Management should emphasize facilitating recruitment subsidies and limiting the presence of C. odorata.
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Forest governance, conservation and livelihoods: the case of forest protected areas and local communities in north-western Zimbabwe
- Authors: Mutekwa, Vurayai
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7396 , vital:21254
- Description: Forest protected areas (FPAs) constitute one of the main strategies for achieving the triple benefits of biodiversity conservation, livelihoods sustenance and climate regulation. The quality of FPA governance plays a major role in the achievement of these conservation objectives. Governance encompasses policies, institutions, actors, processes and power and how they interplay to determine conservation outcomes. Currently, no research has systematically explored the historical and contemporary governance of Zimbabwe’s protected indigenous forests and its implications on forest condition and local communities’ livelihoods. This is despite the fact that improving forest governance depends on learning from those that prevailed in the past as well as those currently obtaining on the ground in terms of how they have performed in relation to conservation and livelihood sustenance. This study assessed Zimbabwe’s historical and contemporary FPA governance and its implications on social and ecological outcomes. The overall rationale of the study was to provide evidence of the impact of past governance arrangements on forest condition and local communities’ livelihoods, improve understanding of the current governance arrangements and propose future FPA governance strategies and mechanisms to enhance conservation and local communities’ livelihood outcomes. Accordingly, the specific objectives of the study were to: 1) characterize and collate historical governance of FPAs in western Zimbabwe, 2) evaluate the impact of governance on forest condition and local communities’ livelihoods, 3) explore the nature of contemporary governance at the forest level, and 4) propose the governance model for Zimbabwe’s FPAs into the future. The study employed a combination of quantitative and qualitative data collection and analysis methods including the systematic literature review methodology. Using specific case studies of indigenous FPAs in western Zimbabwe as examples, the study initially evaluated through literature review (Chapter 2) the history of forest governance in Zimbabwe showing how four main powers (force, regulation, market and legitimation) led to different types of local community exclusion and how community agency countered exclusion especially from the year 2000 to date. Chapter 3 uses six case study forests to assess the quality of historical FPA governance by analyzing the application of seven governance principles. The results showed that the quality of governance was high during precolonial times, deteriorated with the inception of colonialism and remained poor after independence in 1980. Forest condition also varied in tandem with the quality of governance variations showing a positive relationship between the two variables. Participation in decision making, fairness in sharing benefits and effective rule enforcement emerged as key principles for FPA authorities to earn local community support and improve forest condition. Chapter 4 employed remote sensing techniques to determine the impact of governance on FPA land cover change by comparing FPAs with in situ and ex situ inhabitants. Results revealed that there was a significant relationship between governance quality and land cover change. FPAs with in situ inhabitants experienced higher forest loss than those with ex situ inhabitants. Poor governance accelerated forest conversion to other land uses particularly agriculture and settlement. Chapter 5 explored contemporary FPA governance at the forest level. Results showed that human agency that led to the invasion of FPAs from the year 2000 onwards disrupted the governance arrangements that were previously in place subjecting Zimbabwe’s FPAs to near open access by local communities and other actors. The FPAs’ contemporary governance is characterized by involvement of multiple actors with diverse interests, lack of Forestry Commission legitimacy, very low levels of local people’s participation in decision making and rule enforcement, lack of compliance with FPA rules and actual benefits that do not match local communities’ expectations. Overall, the study has revealed the ineffectiveness of the conventional centralized FPA governance in achieving positive conservation and local communities’ livelihoods outcomes. The study recommended a shift from conventional centralized governance to pro-people adaptive collaborative management (ACM). This has the potential to address most of the governance ills affecting Zimbabwe’s FPAs if it is designed and implemented with the full commitment of all relevant actors. This governance approach should, however, avoid some of the pitfalls such as elite capture, corruption in benefit sharing, gender inequality and technocratic professional management approaches that have characterized some collaborative governance systems in developing countries further perpetuating marginalization and poverty amongst local communities. Forestry Commission must also exercise visionary leadership and motivation. ACM becomes possible through leadership, vision, establishment and maintenance of links through culture and management and high levels of motivation. Designing and implementing ACM avoiding the highlighted pitfalls improves the capacity of the FPAs to continue providing social and ecological benefits such as improvement of local communities’ livelihoods, biodiversity protection and climate change mitigation.
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Formulation development, manufacture and evaluation of hydralazine hydrochloride microspheres
- Authors: Kangausaru, Shakemore Tinashe
- Date: 2017
- Subjects: Hydralazine , Microspheres , Drugs Controlled release , Drugs Design , Drug development , Hypertension Chemotherapy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59220 , vital:27482
- Description: Despite improvements in its detection and treatment since the 1970s, hypertension is the most common and important risk factor for cardiovascular diseases. Hypertension is a chronic condition often underdiagnosed and/or inadequately treated in Sub-Saharan Africa. Recent survey results illustrate that the condition continues to contribute significantly to mortality and morbidity in adults and that it is poorly controlled in clinical practice. Hydralazine (HYD) is used either alone or in combination for the management of chronic hypertension, chronic cardiac failure and hypertensive crises. Due to its short plasma half-life of between 2 to 4 hours, HYD is normally administered two to four times daily, therefore making it a potential candidate for inclusion in sustained release formulations. The formulation of sustained release microsphere dosage forms may be useful to improve patient adherence and to achieve predictable and optimised therapeutic plasma concentrations. A stability indicating reversed-phase high performance liquid chromatography (RP-HPLC) method for the quantitation of HYD in pharmaceutical dosage forms was developed and optimised using a Central Composite Design (CCD) approach. UV/Vis detection method was selected as HYD contains an ultraviolet light-absorbing chromophore. The method was validated with respect to linearity and range, limits of quantitation (LOQ) and detection (LOD), accuracy, precision, sensitivity, selectivity and specificity as per International Conference on Harmonisation (ICH) guidelines. The method was applied to commercially available HYD tablets. No interfering peaks were observed from excipients used in the commercially available tablets. Preformulation studies were conducted to ensure the manufacture of high quality, stable sustained release HYD microspheres. The results revealed that there was an interaction between HYD and Carbopol® 971P, therefore Carbopol® polymers were not included during formulation studies. HYD was found to be compatible with Methocel® K100LV, Eudragit® RS PO and Avicel® 101 and HYD formulations were developed and optimised using these excipients. An oil-in-oil (o/o) solvent evaporation technique was selected for the manufacture of HYD microspheres due to its simplicity and to avoid exposure of HYD to moisture that could have been encountered if a water-in-oil (w/o) manufacturing process was used. The selection of o/o solvent evaporation technique was also based on the hydrophilicity of HYD and the polymers selected. Different grades of Methocel® and Eudragit® were selected to evaluate their effect on encapsulation efficiency (EE), in vitro release and microparticle shape and morphology. The best combination of these polymers which resulted in the desired EE, in vitro release, microparticle shape and size were then selected for formulation optimisation. A numerical optimisation approach was used to predict a formulation composition that would produce minimal HYD release initially and maximum HYD release after 12 hours of dissolution testing. The release kinetics of HYD from the manufactured microspheres were established by fitting in vitro release data to several mathematical models. The in vitro release data for the optimised formulations was best described using Higuchi model. The short-term stability of the optimised formulations was established by undertaking stability studies at 4°C, 25 °C/60 % RH and 40 °C/75 % RH. The results revealed that there was no significant change in appearance and physicochemical properties of the microspheres over a period of one month. However, long-term stability studies would be required to determine the shelf-life of the formulations. In addition, a gas chromatographic (GC) method was selected for determining residual amounts of acetone and n-hexane in the optimised formulations. GC methods were developed and optimised by evaluation of process parameters. System suitability testing was performed with respect to resolution, theoretical number of plates and selectivity. Method validation was performed with respect to linearity, range, inter- and intra-day precision, retention time (Rt) precision, limit of quantitation (LOQ) and detection (LOD). A solvent extraction method was used to analyse residual solvents in the optimised formulations. The drying process was sufficient in evaporating acetone and n-hexane from the optimised formulations. Solvent evaporation technique has been successfully used in the manufacture of HYD microspheres. The microspheres have potential for further development, scale up formulation studies and long-term stability studies. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
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Formulation, development and evaluation of lipid nanocarriers for minocycline hydrochloride
- Authors: Ranchhod, Janeeta
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65234 , vital:28712
- Description: Expected release date-May 2019
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Fraction-specific geochemistry across the Asbestos Hills BIF of the Transvaal Supergroup, South Africa: implications for the origin of BIF and the history of atmospheric oxygen
- Authors: Oonk, Paul Bernardus Hendrikus
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/50721 , vital:26021
- Description: Banded iron formations (BIF), deposited prior to and concurrent with the Great Oxidation Event (GOE) at ca. 2.4 Ga, record changes in oceanic and atmospheric chemistry during this critical time interval. Four previously unstudied drill-cores from the Griqualand West Basin, South Africa, capturing the rhythmically mesobanded, deep-water Kuruman BIF and the overlying granular, shallower Griquatown BIF, were sampled every ca. 10 m along core depth. Mineralogically, these BIFs consist of three iron-bearing fractions: (1) Fe-Ca-Mg-Mn carbonates, (2) magnetite with/without minor hematite and (3) Fe-silicates. These fractions are typically fine-grained on a sub-μm scale and their co-occurrence in varying amounts means that bulk-rock or microanalytical geochemical and stable isotope data are influenced by mineralogy.
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From Baudelaire to Beardsley: some thoughts on Poe's beast as an indicator of the tastes and fears of nineteenth-century Europe
- Authors: Beard, Margot
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147781 , vital:38672 , https://doi.org/10.1080/00043389.2001.11876980
- Description: Charles Baudelaire (1821 1867) was one of the major influences on the French Decadent poets of the late nineteenth century whose aesthetic principles were shared, to a large extent, by a group of English poets and artists, among whom was Aubrey Beardsley (1872 1898). One of the major influences on Baude laire had been the American, Edgar Allan Poe (1809 1849), in whose short stories and poems Baudelaire had recognised a kindred spirit. Some intriguing aspects of changing nine teenth century attitudes emerge from a study of Baudelaire's 1856 translation of Poe's `The Murders in the Rue Morgue' and Beardsley's 1893 illustration to this story.
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From dialect to ‘official’ language: towards the intellectualisation of Ndau in Zimbabwe
- Authors: Sithole, Emmanuel
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/6086 , vital:21030
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