Showing items 421 - 440 of 607

Your selections:

Saving and investment in South Africa: a causality study

  • Authors: Mngqibisa, Vuyisa
  • Date: 2014
  • Subjects: Saving and investment -- South Africa Investments -- South Africa Credit -- South Africa Finance, Personal -- South Africa Portfolio management -- South Africa Investment analysis -- South Africa Error analysis (Mathematics)
  • Language: English
  • Type: Thesis , Masters , MCom
  • Identifier: vital:1086 , http://hdl.handle.net/10962/d1011887
  • Description: This study aims to investigate the relationship between private saving and investment for South Africa using a Vector Error Correction Framework. Saving and investment are considered to be important factors for sustainable economic growth in the country, particularly as these variables have been recorded at significantly lower levels than those of other developing nations. By examining the direction of causality between saving and investment, the most suitable policy measures can be used in stimulating either savings or investment, and as a result aggregate growth. The study found a positive two-way causality to exist between these two variables, proving that both saving and investment-led policies are necessary in raising saving and investment levels. With the inclusion of credit extension as the third variable used to remove any variable bias, the study not only found credit extension to Granger cause private saving, but the reverse relationship was found to be present as well. This relationship was however found to be negative, confirming that lower borrowing constraints may have a negative effect on saving levels. The negative relationship between credit supply and private saving (substitution effect) proves that credit supply will only yield a positive result for savings if channelled through investment expenditure.
  • Full Text:

Screening of entomopathogenic fungi against citrus mealybug (Planococcus citri (Risso)) and citrus thrips (Scirtothrips aurantii (Faure))

  • Authors: FitzGerald, Véronique Chartier
  • Date: 2014
  • Subjects: Entomopathogenic fungi , Citrus mealybug -- South Africa -- Eastern Cape , Citrus thrips -- South Africa -- Eastern Cape , Citrus -- Diseases and pests , Citrus mealybug -- Biological control , Citrus thrips -- Biological control , Biological pest control agents , Scanning electron microscopy , Mycoses
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4166 , http://hdl.handle.net/10962/d1020887
  • Description: Mealybugs (Planococcus citri) and thrips (Scirtothrips aurantii) are common and extremely damaging citrus crop pests which have proven difficult to control via conventional methods, such as chemical pesticides and insect growth regulators. The objective of this study was to determine the efficacy of entomopathogenic fungi against these pests in laboratory bioassays. Isolates of Metarhizium anisopliae and Beauveria bassiana from citrus orchards in the Eastern Cape, South Africa were maintained on Sabouraud Dextrose 4% Agar supplemented with Dodine, chloramphenicol and rifampicin at 25°C. Infectivity of the fungal isolates was initially assessed using 5th instar false codling moth, Thaumatotibia leucotreta, larvae. Mealybug bioassays were performed in 24 well plates using 1 x 107 ml-1 conidial suspensions and kept at 26°C for 5 days with a photoperiod of 12 L:12 D. A Beauveria commercial product and an un-inoculated control were also screened for comparison. Isolates GAR 17 B3 (B. bassiana) and FCM AR 23 B3 (M. anisopliae) both resulted in 67.5% mealybug crawler mortality and GB AR 23 13 3 (B. bassiana) resulted in 64% crawler mortality. These 3 isolates were further tested in dose-dependent assays. Probit analyses were conducted on the dose-dependent assays data using PROBAN to determine LC₅₀ values. For both the mealybug adult and crawlers FCM AR 23 B3 required the lowest concentration to achieve LC₅₀ at 4.96 x 10⁶ conidia ml-1 and 5.29 x 10⁵ conidia ml-1, respectively. Bioassays on adult thrips were conducted in munger cells with leaf buds inoculated with the conidial suspensions. Isolate GAR 17 B3 had the highest mortality rate at 70% on thrips while FCM AR 23 B3 resulted in 60% mortality. Identification of the isolates, FCM AR 23 B3, GAR 17 B3 and GB AR 23 13 3, were confirmed to be correct using both microscopic and molecularly techniques. ITS sequences were compared to other sequences from GenBank and confirmed phylogenetically using MEGA6. Mealybug infection was investigated using scanning electron microscopy, mycosis was confirmed but the infection process could not be followed due to the extensive waxy cuticle. These results indicate that there is potential for the isolates FCM AR 23 B3 and GAR 17 B3 to be developed as biological control agents for the control of citrus mealybug and thrips. Further research would be required to determine their ability to perform under field conditions.
  • Full Text:

Secrets I keep

Sediment linkages in a small catchment in the Mount Fletcher southern Drakensberg region, South Africa

  • Authors: Mzobe, Pearl Nonjabulo
  • Date: 2014
  • Subjects: Soil erosion -- South Africa -- Mount Fletcher , Soil conservation -- South Africa -- Mount Fletcher , Soil degradation -- South Africa -- Mount Fletcher , Food security -- South Africa , Wetland management -- South Africa -- Mount Fletcher , Watersheds -- South Africa -- Mount Fletcher
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:4879 , http://hdl.handle.net/10962/d1013224
  • Description: Soil erosion is a persistent problem that requires continued control efforts as agricultural land loses productivity and communities dependent on the land become increasingly vulnerable to decreased food security. The negative effects of soil erosion in Khamopele River catchment, in the Mount Fletcher southern Drakensberg region of South Africa, are manifest in extensive gullying and wetland loss. Soil erosion has resulted in siltation in a recently constructed dam and the alteration of aquatic habitats. This research was undertaken to identify the sources of eroded sediment in the small upper catchments of the Mzimvubu River catchment to inform broader catchment management strategies. The scale of erosion was quantified using field surveys of gully extent and form. Environmental magnetic tracing techniques were used to determine the sources of eroded sediment in Khamopele River and upper Tina River catchments. The radionuclide ¹³⁷Cs was used to determine soil loss over a 55 year period in Khamopele River catchment. The Landscape Connectivity framework was used to describe the sediment source, pathway and sink interactions at sample area level. Results indicated that historical and contemporary land management practices such as uncontrolled grazing, grassland burning and furrows promoted soil erosion in the catchment. Soil erosion was most pronounced in the Taung sample area where there was extensive gullying, tunnelling and subsurface erosion. Environmental magnetic tracing results indicated that there were clear differences in source areas. Despite its prevalence in the area, gully erosion was not shown to be a major source of sediment to downstream sinks. Topsoil and hillslope derived sediment were shown to be mobile in the catchment, suggesting that sheet erosion processes were dominant in the catchment. Radionuclide tracing studies showed that at least 20 cm of soil had been eroded from the Khamopele River catchment surface since 1956. This research has shown that it is possible to distinguish source areas of erosion in the catchment by matching catchment mineral magnetic signatures to those in sink areas. This means that rehabilitation projects can use resources efficiently as the areas needing the most attention can be identified.
  • Full Text:

Selective modulation of plasmodial Hsp70s by small molecules with antimalarial activity

  • Authors: Cockburn, Ingrid , Boshoff, Aileen , Pesce, Eva-Rachele , Blatch, Gregory L
  • Date: 2014
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/431192 , vital:72752 , xlink:href="https://doi.org/10.1515/hsz-2014-0138"
  • Description: Plasmodial heat shock protein 70 (Hsp70) chaperones represent a promising new class of antimalarial drug targets because of the important roles they play in the survival and pathogenesis of the malaria parasite Plasmodium falciparum. This study assessed a set of small molecules (lapachol, bromo-β-lapachona and malonganenones A, B and C) as potential modulators of two biologically important plasmodial Hsp70s, the parasite-resident PfHsp70-1 and the exported PfHsp70-x. Compounds of interest were assessed for modulatory effects on the steady-state basal and heat shock protein 40 (Hsp40)-stimulated ATPase activities of PfHsp70-1, PfHsp70-x and human Hsp70, as well as on the protein aggregation suppression activity of PfHsp70-x. The antimalarial marine alkaloid malonganenone A was of particular interest, as it was found to have limited cytotoxicity to mammalian cell lines and exhibited the desired properties of an effective plasmodial Hsp70 modulator. This compound was found to inhibit plasmodial and not human Hsp70 ATPase activity (Hsp40-stimulated), and hindered the aggregation suppression activity of PfHsp70-x. Furthermore, malonganenone A was shown to disrupt the interaction between PfHsp70-x and Hsp40. This is the first report to show that PfHsp70-x has chaperone activity, is stimulated by Hsp40 and can be specifically modulated by small molecule compounds.
  • Full Text:

Sequence and domain conservation of the coelacanth Hsp40 and Hsp90 chaperones suggests conservation of function

  • Authors: Tastan Bishop, Özlem , Edkins, Adrienne L , Blatch, Gregory L
  • Date: 2014
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/126932 , vital:35936 , https://doi.10.1002/jez.b.22541
  • Description: Molecular chaperones and their associated co‐chaperones play an important role in preserving and regulating the active conformational state of cellular proteins. The chaperone complement of the Indonesian Coelacanth, Latimeria menadoensis, was elucidated using transcriptomic sequences. Heat shock protein 90 (Hsp90) and heat shock protein 40 (Hsp40) chaperones, and associated cochaperones were focused on, and homologous human sequences were used to search the sequence databases. Coelacanth homologs of the cytosolic, mitochondrial and endoplasmic reticulum (ER) homologs of human Hsp90 were identified, as well as all of the major co‐chaperones of the cytosolic isoform. Most of the human Hsp40s were found to have coelacanth homologs, and the data suggested that all of the chaperone machinery for protein folding at the ribosome, protein translocation to cellular compartments such as the ER and protein degradation were conserved. Some interesting similarities and differences were identified when interrogating human, mouse, and zebrafish homologs. For example, DnaJB13 is predicted to be a non‐functional Hsp40 in humans, mouse, and zebrafish due to a corrupted histidine‐proline‐aspartic acid (HPD) motif, while the coelacanth homolog has an intact HPD. These and other comparisons enabled important functional and evolutionary questions to be posed for future experimental studies.
  • Full Text:

Shame, divine cannibalism, and the spectacle of subaltern suffering in Ken Barris's What Kind of Child:

  • Authors: Marais, Mike
  • Date: 2014
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/144028 , vital:38304 , https://hdl.handle.net/10520/EJC171544
  • Description: This essay examines the aesthetic and ethical dimensions of Ken Barns's portrayal of the life of a street child in What Kind of Child. Responses to literary representations of subaltem suffering are sharply divided. On the one hand, there is the commonsense view that such representations require one to imagine what the situation of other people may be like, and that, in doing so, one opens oneself to their experience of life. To the extent that representations of suffering inspire one to reflect on one's relations to others, they are salutary. On the other hand, though, such depictions, like poverty tourism, may be accused of providing a spectacle of distant suffering that one vicariously experiences from a position of privilege and then dircards.
  • Full Text:

Shembe religion's integration of African traditional religion and Christianity : a sociological case study

  • Authors: Shange, Nombulelo Tholithemba
  • Date: 2014
  • Subjects: Shembe Church Christianity and other religions -- South Africa -- Inanda Christianity and culture -- South Africa -- Inanda Independent churches -- South Africa -- Inanda Religious tolerance -- South Africa -- Inanda South Africa -- Religious life and customs
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3365 , http://hdl.handle.net/10962/d1011819
  • Description: The Shembe Church's integration of African Traditional Religion and Christianity has been met by many challenges. This merger has been rejected by both African traditionalists and Christians. The Shembe Church has been met by intolerance even though the movement in some ways creates multiculturalism between different people and cultures. This thesis documents the Shembe Church's ideas and practices; it discusses how the Shembe Church combines two ideologies that appear to be at odds with each other. In looking at Shembe ideas and practices, the thesis discusses African religion-inspired rituals like ukusina, ancestral honouring, animal sacrificing and virgin testing. The thesis also discusses the heavy Christian influence within the Shembe Church; this is done by looking at the Shembe Church's use of The Bible and Moses' Laws which play a crucial role in the Church. The challenges the Shembe Church faces are another main theme of the thesis. The thesis looks at cases of intolerance and human rights violations experienced by Shembe members. This is done in part by looking at the living conditions at eBuhleni, located at Inanda, KZN. The thesis also analyses individual Shembe member's experiences and discusses how some members of the Shembe church experience the acceptance of the Shembe religion in South African society. This thesis concludes by trying to make a distinction between intolerance and controversy. I try to highlight the idea that what many Shembe followers see as discrimination and intolerance towards them is sometimes a difference in opinion from other cultural groups. Sometimes these differences are not geared towards criticising other religious groups or perpetuating intolerance.
  • Full Text:

Simple, illustrated medicines information improves ARV knowledge and patient self-efficacy in limited literacy South African HIV patients:

  • Authors: Dowse, Roslind , Barford, Kirsty-Lee , Browne, Sara H
  • Date: 2014
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/156698 , vital:40039 , DOI: 10.1080/09540121.2014.931559
  • Description: Few studies have investigated antiretroviral (ARV) knowledge and self-efficacy in limited literacy patients. Using a randomized controlled study design, we investigated the influence of a simple pre-tested patient information leaflet (PIL) containing both text and illustrations on HIV- and ARV-related knowledge and on self-efficacy over six months in a limited literacy African population. The recruited patients were randomly allocated to either control (standard care) or intervention group (standard care plus illustrated PIL). HIV and medicines-related knowledge was evaluated with a 22-question test at baseline, one, three, and six months. Self-efficacy was assessed using a modified version of the HIV Treatment Adherence Self-Efficacy Scale.
  • Full Text:

Smallholder farmers’ access to credit in the Amathole District Municipality, Eastern Cape Province, South Africa

  • Authors: Baiyegunhi, Lloyd J S , Fraser, Gavin C G
  • Date: 2014
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/69351 , vital:29503 , https://jarts.info/index.php/jarts/article/view/2014121946870/814
  • Description: Provision of credit has being identified as an important instrument for improving the welfare of smallholder farmers directly and for enhancing productive capacity through financing investment by the farmers in their human and physical capital. This study investigated the individual and household characteristics that influence credit market access in Amathole District Municipality, Eastern Cape Province, South Africa, using a cross sectional data from smallholder farmers’ household survey. The aim is to provide a better understanding of the households’ level socio-economic characteristics, not only because they influence household’s demand for credit but also due to the fact that potential lenders are most likely to base their assessment of borrowers’ creditworthiness on such characteristics. The results of the logistic regression suggest that credit market access was significantly influenced by variables such as gender, education, households’ income, value of assets, savings, dependency ratio, repayment capacity and social capital. Implications for rural credit delivery are discussed.
  • Full Text:

Social learning in community based natural resource management project (CBNRM) : a case study of Chipembere gardening project in Zimbabwe.

  • Authors: Mukwambo, Robson
  • Date: 2014
  • Subjects: Social learning -- Zimbabwe , Social learning -- Case studies , Vegetable gardening -- Zimbabwe , Economic development projects -- Zimbabwe
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:2014 , http://hdl.handle.net/10962/d1016363
  • Description: This investigation of social learning processes in the Chipembere gardening project was conducted in Rockvale village one in Sebakwe communal area in the Midlands province of Zimbabwe. In essence, the study sought to explore how the Chipembere gardening project as a community-based natural resource management initiative (CBNRM), was reflecting and supporting social learning processes of change. It also sought to enrich and deepen an organizational understanding of social learning and to generate ideas and draw recommendations that could be used to strengthen learning in other CBNRM projects. The research was undertaken as a qualitative case study with data generated through semi-structured interviews with individuals and groups. It also included an analysis of project documents and an extended period of participant observation on site and in the gardening activities. Data were indexed and coded for generating analytical memos that were used to extract and represent the scope of social learning interations within the developing project. The study found that within the Chipembere gardening project a wide range of learning interactions were significant in shaping the developing project. Furthermore, these interactions were earmarked as the major drivers of social learning processes within the project. The study concluded that the social learning interactions amongst the gardeners in the Chipembere community garden were instrumental in fostering change that enhanced community livelinhoods and wellbeing.
  • Full Text:

Some general convergence theorems on fixed points

  • Authors: Panicker, Rekha Manoj
  • Date: 2014
  • Subjects: Fixed point theory , Convergence , Coincidence theory (Mathematics)
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5426 , http://hdl.handle.net/10962/d1013112
  • Description: In this thesis, we first obtain coincidence and common fixed point theorems for a pair of generalized non-expansive type mappings in a normed space. Then we discuss two types of convergence theorems, namely, the convergence of Mann iteration procedures and the convergence and stability of fixed points. In addition, we discuss the viscosity approximations generated by (ψ ,ϕ)-weakly contractive mappings and a sequence of non-expansive mappings and then establish Browder and Halpern type convergence theorems on Banach spaces. With regard to iteration procedures, we obtain a result on the convergence of Mann iteration for generalized non-expansive type mappings in a Banach space which satisfies Opial's condition. And, in the case of stability of fixed points, we obtain a number of stability results for the sequence of (ψ,ϕ)- weakly contractive mappings and the sequence of their corresponding fixed points in metric and 2-metric spaces. We also present a generalization of Fraser and Nadler type stability theorems in 2-metric spaces involving a sequence of metrics.
  • Full Text:

Some life-history parameters of the non-native amphipod Platorchestia platensis (Talitridae) in a warm temperate South African estuary

  • Authors: Hodgson, Alan N , Booth, Anthony J , David-Engelbrecht, Viginia , Henninger, Tony O
  • Date: 2014
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/126976 , vital:35940 , https://doi.10.1080/0035919X.2014.941961
  • Description: Density, population structure, growth, mortality and aspects of reproduction of the non-native amphipod Platorchestia platensis were studied for 20 consecutive months (October 2008 to May 2010) in the supralittoral wrack of the Knysna Estuary, South Africa. Amphipod density varied over the sampling period with the lowest numbers recorded in summer (January and February). Ovigerous females with embryos, and juveniles were found in most months with peaks in recruitment found in both April and October, suggesting that in Knysna this species is a biannual breeder. Average female size was significantly greater in winter, with larger females tending to brood more embryos. The largest adults (13.5 mm total length) were always male although the monthly sex ratio was nearly always female biased. Growth rate estimated from a cohort analysis was about 1 mm per month and monthly survival about 69%. The ability to reproduce all year round may be one reason why this introduced species has become established within this warm temperate estuary.
  • Full Text:

Sorption of hydrophobic organic compounds on natural sorbents and organoclays from aqueous and non-aqueous solutions: a mini-review

  • Authors: Moyo, Francis , Tandlich, Roman , Wilhelmi, Brendan S , Balaz, Stefan
  • Date: 2014
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/71614 , vital:29925 , https://doi.org/10.3390/ijerph110505020
  • Description: Renewed focus on the sorption of hydrophobic organic chemicals (HOCs) onto mineral surfaces and soil components is required due to the increased and wider range of organic pollutants being released into the environment. This mini-review examines the possibility of the contribution and mechanism of HOC sorption onto clay mineral sorbents such as kaolinite, and soil organic matter and the possible role of both in the prevention of environmental contamination by HOCs. Literature data indicates that certain siloxane surfaces can be hydrophobic. Therefore soils can retain HOCs even at low soil organic levels and the extent will depend on the structure of the pollutant and the type and concentration of clay minerals in the sorbent. Clay minerals are wettable by nonpolar solvents and so sorption of HOCs onto them from aqueous and non-aqueous solutions is possible. This is important for two reasons: firstly, the movement and remediation of soil environments will be a function of the concentration and type of clay minerals in the soil. Secondly, low-cost sorbents such as kaolinite and expandable clays can be added to soils or contaminated environments as temporary retention barriers for HOCs. Inorganic cations sorbed onto the kaolinite have a strong influence on the rate and extent of sorption of hydrophobic organic pollutants onto kaolinite. Structural sorbate classes that can be retained by the kaolinite matrix are limited by hydrogen bonding between hydroxyl groups of the octahedral alumosilicate sheet and the tetrahedral sheet with silicon. Soil organic carbon plays a key role in the sorption of HOCs onto soils, but the extent will be strongly affected by the structure of the organic soil matter and the presence of soot. Structural characterisation of soil organic matter in a particular soil should be conducted during a particular contamination event. Contamination by mining extractants and antibiotics will require renewed focus on the use of the QSAR approaches in the context of the sorption of HOCs onto clay minerals from aqueous and non-aqueous solutions.
  • Full Text:

South Africa's 'Border War': contested narratives and conflicting memories

  • Authors: Baines, Gary F
  • Date: 2014
  • Language: English
  • Type: text , book
  • Identifier: http://hdl.handle.net/10962/67115 , vital:29033 , https://www.bloomsbury.com/uk/south-africas-border-war-9781472508249/
  • Description: publisher version , South Africa's 'Border War' provides a timely study of the 'war of words' waged by retired South African Defence Force (SADF) generals and other veterans against critics and detractors. The book explores the impact of the 'Border War' on South African culture and society during apartheid and in the new dispensation and discusses the lasting legacy or 'afterlife' of the war in great detail. It also offers an appraisal of the secondary literature of the 'Border War', supplemented by archival research, interviews and an analysis of articles, newspaper reports, reviews and blogs. Adopting a genuinely multidisciplinary approach that borrows from the study of history, literature, visual culture, memory, politics and international relations, South Africa's 'Border War' is an important volume for anyone interested in the study of war and memory or the modern history of South Africa.
  • Full Text: false

South Africa, quality of life

  • Authors: Moller, Valerie , Roberts, Benjamin J
  • Date: 2014
  • Language: English
  • Type: text , book
  • Identifier: http://hdl.handle.net/10962/67255 , vital:29064 , https://doi.org/10.1007/978-94-007-0753-5
  • Description: publisher version , The aim of this encyclopedia is to provide a comprehensive reference work on scientific and other scholarly research on the quality of life, including health-related quality of life research or also called patient-reported outcomes research. Since the 1960s two overlapping but fairly distinct research communities and traditions have developed concerning ideas about the quality of life, individually and collectively, one with a fairly narrow focus on health-related issues and one with a quite broad focus. In many ways, the central issues of these fields have roots extending to the observations and speculations of ancient philosophers, creating a continuous exploration by diverse explorers in diverse historic and cultural circumstances over several centuries of the qualities of human existence. What we have not had so far is a single, multidimensional reference work connecting the most salient and important contributions to the relevant fields. Entries are organized alphabetically and cover basic concepts, relatively well established facts, lawlike and causal relations, theories, methods, standardized tests, biographic entries on significant figures, organizational profiles, indicators and indexes of qualities of individuals and of communities of diverse sizes, including rural areas, towns, cities, counties, provinces, states, regions, countries and groups of countries.
  • Full Text: false

South African International Relations (Ir) and the China-Africa relationship: a critical reflection

  • Authors: Walker, Timothy Charles
  • Date: 2014
  • Subjects: South Africa -- Relations -- China , China -- Relations -- South Africa , International relations -- Philosophy , Critical theory
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2885 , http://hdl.handle.net/10962/d1015518
  • Description: South African International Relations (IR) is a prominent source of China-Africa research and analysis, producing reports, journal articles and books that seek to illuminate the emerging relationship between China and Africa. It plays an important role in the framing of the relationship, as well as how it is perceived outside of the discipline. However, critical concerns have been raised about the context within which South African IR operates. It is therefore important that IR research, including its assumptions, dominant concepts, professed values and aspirations to studying the China-Africa relationship, be critically examined. The aim of this thesis is to contribute to critical thinking in South African IR by opening up for future discussion the new directions and possibilities for China-Africa IR. Utilising a critique located in Critical International Relations Theory (CIRT), this thesis critically reflects upon both the context of South African IR’s China-Africa research and the perspectives it has produced. The thesis argues that in spite of many descriptive and empirical studies, China- Africa research is theoretically underdeveloped in South African IR. Further, it argues that theoretical work is marginalised despite the fact that both historical and contemporary research relies on concepts drawn from IR theory. South African IR’s focus on policy relevance is advanced as a reason for the prevalence of theoretical underdevelopment. This thesis concludes by reviewing arguments for the improved use of IR theory in China-Africa IR, which will lead to a better understanding of this important relationship.
  • Full Text:

Southern African Journal of Gerontology

  • Authors: Ferreira, Monica (editor) , Møller, Valerie (editor) , HSRC/UCT Centre for Gerontology
  • Date: 2014
  • Subjects: Gerontology
  • Language: English
  • Type: Text
  • Identifier: vital:8063 , http://hdl.handle.net/10962/d1012653
  • Description: Professor Monica Ferreira, Retired Director of the Institute of Ageing in Africa, Faculty of Health Sciences, University of Cape Town, was the founding editor of the journal (SAJG) and Emeritus Professor Valerie Møller was the associate editor for all nine volumes. The journal was SAPSE accredited. Publication of the journal ceased in 2000. With this letter permission is granted for making SAJG available online on the Rhodes Digital Commons.
  • Full Text:

Spectral properties and photophysical behaviour of water soluble cationic Mg (II) and Al (III) phthalocyanines

  • Authors: Idowu, Mopelola A , Arslanoğlu, Yasin , Nyokong, Tebello
  • Date: 2014
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/241549 , vital:50949 , xlink:href="https://doi.org/10.2478/s11532-013-0388-z"
  • Description: Peripherally and non-peripherally tetrasubstituted-[(N-methyl-2-pyridylthio)]phthalocyaninato magnesium (II) (5 and 6) and chloro aluminium (III) (7 and 8) tetraiodide have been synthesized and characterized. The photophysical properties of the complexes in dimethyl sulfoxide (DMSO) and aqueous medium in the presence and absence of cremophore EL have been studied. These complexes show high solubility in aqueous medium though they were aggregated. The triplet state quantum yields (FT) and the triplet lifetimes (tT) were found to be higher in DMSO with ΦT ranging from 0.32 to 0.51, while tT ranged from 282 to 622 ms in DMSO, compared to aqueous medium (pH 7.4 buffer) where ΦT ranged from 0.15 to 0.19 and tT from 26 to 35 ms. Addition of cremophore EL in aqueous solution resulted in partial disaggregation and increased photoactivity. The fluorescence lifetimes of the complexes showed strong dependence on their immediate environment. The ionic magnesium(II) and aluminium(III) phthalocyanines strongly bind to bovine serum albumin (BSA).
  • Full Text:

Stable isotope ratios indicate differential omnivory among syntopic rocky shore suspension-feeders

  • Authors: Richoux, Nicole B , Vermeulen, Ilke , Froneman, P William
  • Date: 2014
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/68261 , vital:29224 , https://doi.org/10.1007/s00227-013-2358-6
  • Description: Publisher version , We utilised stable isotope ratios to assess differences in diet among three indigenous and syntopic rocky shore suspension-feeders (mussels Perna perna, barnacles Tetraclita serrata, and polychaetes Gunnarea gaimardi). We also determined the spatial and temporal variability in the suspension-feeder diets by collecting specimens on two occasions from two regions adjacent to hydrologically distinct river mouths (i.e. one with larger annual freshwater throughput than the other). The results showed that the isotopic niches (used as proxies for trophic niches) of the three species did not overlap and that the barnacles occupied a trophic position (3.4) well above those of the mussels (2) and polychaetes (2.6). We ascribed the interspecific differences primarily to the disparate feeding mechanisms used by the species. Large-scale regional (~50 km) differences in suspension-feeder diets were apparent, but not small-scale (up to a few km north and south of each estuary mouth). The regional differences in diet resulted from the increased availability of estuarine-origin suspended particulate matter (SPM) and zooplankton in the region adjacent to the river with relatively larger freshwater output, although overall incorporation of zooplankton versus mixed SPM into consumer diets was relatively consistent between regions and through time. Temporal shifts in suspension-feeder diets were apparent from stable carbon isotope ratios in the consumers. Our results showcase the measurable effects of regional-scale processes that can alter the food sources for dominant primary consumers in the rocky intertidal, thus potentially affecting entire food webs through bottom-up processes. The clear evidence for trophic niche partitioning offers valuable insights into how potentially strong competitors can coexist.
  • Full Text: false
  • Disclaimer
  • Privacy
  • Copyright
  • Contact