Johannesburg, South Africa

University of South Africa
Johannesburg, South Africa

The University of South Africa is the largest university on the African continent and attracts a third of all higher education students in South Africa. The university has a student headcount of over 300,000 students, including African and international students in 130 countries worldwide, making it one of the world's mega universities.Unisa is a dedicated open distance education institution. Open distance learning entails a student-centred approach that gives students flexibility and choice over what, when, where, and how they learn, and provides them with extensive student support.As a comprehensive university, Unisa offers both vocational and academic programmes, many of which have received international accreditation, as well as an extensive geographical footprint, giving their students recognition and employability in many countries the world over. Wikipedia.

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Agency: European Commission | Branch: FP7 | Program: CSA | Phase: INFRA-2012-3.3. | Award Amount: 1.07M | Year: 2012

The Virtual Atomic and Molecular Data Centre (VAMDC) is a major new European initiative now building a unified, secure, documented, flexible and interoperable e-science environment-based interface to 17 existing A\M databases.\nThe SUP@VAMDC (Support at VAMDC) aims at building upon the VAMDC e-infrastructure, supporting different studies and actions linked to the VAMDC e-infrastructure that will in accord with the mission of INFRA-2012-3.3:.\n\tProvide operational, legal and technologicalsupport for studies aimed at developing a sustainable open scientific data e- infrastructure in Atomic and Molecular Data.\n\tProvide the support and medium for including authentication, authorisation and accounting (AAA) as well as licensing and tools within the VAMDC brand\n\tPromote and fashions future interoperability (technical, semantic, reference architecture, etc) across A&M data community through the promotion, monitoring and adoption of common standards.\n\tProvide support for dissemination actions aimed at raising the visibility of the VAMDC e-infrastructure towards wider audiences such as other domains which could use the VAMDC e-infrastructure for their own science or for their own dissemination of data, such as students and/or citizen-scientists. This programme includes the development of education-related tools linking VAMDCs scientific repositories and research data infrastructures, including establishing a free open access repository containing all peer-reviewed articles resulting from the VAMDC programme.\n\tProvide support in developing a globally connected and interoperable VAMDC e-infrastructure between EU and the rest of the world, including Brazil , South Africa, Asia, Australia, India through hosting workshops and supporting dialogue between such synergistic structures.\n\tAnalyse and evaluate possible business models for supporting an Open Science model (OPEN VAMDC) whilst assessing the impact of such a modeling in achieving financial sustainability.

Parawira W.,Kigali Institute of Science and Technology | Tekere M.,University of South Africa
Critical Reviews in Biotechnology | Year: 2011

One of the major challenges faced in commercial production of lignocellulosic bioethanol is the inhibitory compounds generated during the thermo-chemical pre-treatment step of biomass. These inhibitory compounds are toxic to fermenting micro-organisms. The ethanol yield and productivity obtained during fermentation of lignocellulosic hydrolysates is decreased due to the presence of inhibiting compounds, such as weak acids, furans and phenolic compounds formed or released during thermo-chemical pre-treatment step such as acid and steam explosion. This review describes the application and/or effect of biological detoxification (removal of inhibitors before fermentation) or use of bioreduction capability of fermenting yeasts on the fermentability of the hydrolysates. Inhibition of yeast fermentation by the inhibitor compounds in the lignocellulosic hydrolysates can be reduced by treatment with enzymes such as the lignolytic enzymes, for example, laccase and micro-organisms such as Trichoderma reesei, Coniochaeta ligniaria NRRL30616, Trametes versicolor, Pseudomonas putida Fu1, Candida guilliermondii, and Ureibacillus thermosphaericus. Microbial and enzymatic detoxifications of lignocellulosic hydrolysate are mild and more specific in their action. The efficiency of enzymatic process is quite comparable to other physical and chemical methods. Adaptation of the fermentation yeasts to the lignocellulosic hydrolysate prior to fermentation is suggested as an alternative approach to detoxification. Increases in fermentation rate and ethanol yield by adapted micro-organisms to acid pre-treated lignocellulosic hydrolysates have been reported in some studies. Another approach to alleviate the inhibition problem is to use genetic engineering to introduce increased tolerance by Saccharomyces cerevisiae, for example, by overexpressing genes encoding enzymes for resistance against specific inhibitors and altering co-factor balance. Cloning of the laccase gene followed by heterologous expression in yeasts was shown to provide higher enzyme yields and permit production of laccases with desired properties for detoxification of lignocellulose hydrolysates. A combination of more inhibitor-tolerant yeast strains with efficient feed strategies such as fed-batch will likely improve lignocellulose-to-ethanol process robustness. © 2011 Informa Healthcare USA, Inc.

Fossette S.,University of South Africa
Proceedings. Biological sciences / The Royal Society | Year: 2014

Large oceanic migrants play important roles in ecosystems, yet many species are of conservation concern as a result of anthropogenic threats, of which incidental capture by fisheries is frequently identified. The last large populations of the leatherback turtle, Dermochelys coriacea, occur in the Atlantic Ocean, but interactions with industrial fisheries could jeopardize recent positive population trends, making bycatch mitigation a priority. Here, we perform the first pan-Atlantic analysis of spatio-temporal distribution of the leatherback turtle and ascertain overlap with longline fishing effort. Data suggest that the Atlantic probably consists of two regional management units: northern and southern (the latter including turtles breeding in South Africa). Although turtles and fisheries show highly diverse distributions, we highlight nine areas of high susceptibility to potential bycatch (four in the northern Atlantic and five in the southern/equatorial Atlantic) that are worthy of further targeted investigation and mitigation. These are reinforced by reports of leatherback bycatch at eight of these sites. International collaborative efforts are needed, especially from nations hosting regions where susceptibility to bycatch is likely to be high within their exclusive economic zone (northern Atlantic: Cape Verde, Gambia, Guinea Bissau, Mauritania, Senegal, Spain, USA and Western Sahara; southern Atlantic: Angola, Brazil, Namibia and UK) and from nations fishing in these high-susceptibility areas, including those located in international waters.

Palladium-CuI catalyzed Sonogashira coupling of 2-aryl-4-chloro-3- iodoquinolines with terminal acetylenes (1 equiv) in triethylamine afforded the 2-aryl-3-(alkynyl)-4-chloroquinolines as sole products. The 2-aryl-4-chloro-3- iodoquinolines coupled with excess terminal acetylenes (2.5 equiv) in dioxane/water to yield the 2-aryl-3,4-bis(alkynyl)quinoline derivatives in a one-pot operation. The 2-aryl-3-(alkynyl)-4-chloroquinolines were, in turn, subjected to arylation via Suzuki cross-coupling with arylboronic acid derivatives or amination with methylamine, respectively. The structures of the products of successive Sonogashira and Suzuki cross-couplings were also confirmed by X-ray crystallography. © 2010 Elsevier Ltd. All rights reserved.

Volunteers are increasingly being relied upon to provide home-based care for people living with AIDS in South Africa and this presents several unique challenges specific to the HIV/AIDS context in Africa. Yet it is not clear what motivates people to volunteer as home-based caregivers. Drawing on the functional theory on volunteer motivations, this study uses data from qualitative interviews with 57 volunteer caregivers of people living with HIV/AIDS in six semi-rural South African communities to explore volunteer motivations. Findings revealed complex motivations underlying volunteering in AIDS care. Consistent with functional theorizing, most of the volunteers reported having more than one motive for enrolling as volunteers. Of the 11 categories of motivations identified, those relating to altruistic concerns for others and community, employment or career benefits and a desire by the unemployed to avoid idleness were the most frequently mentioned. Volunteers also saw volunteering as an opportunity to learn caring skills or to put their own skills to good use, for personal growth and to attract good things to themselves. A few of the volunteers were heeding a religious call, hoping to gain community recognition, dealing with a devastating experience of AIDS in the family or motivated for social reasons. Care organizations' poor understanding of volunteer motives, a mismatch between organizational goals and volunteer motivations, and inadequate funding meant that volunteers' most pressing motives were not satisfied. This led to discontentment, resentment and attrition among volunteers. The findings have implications for home-based care policies and programmes, suggesting the need to rethink current models using non-stipended volunteers in informal AIDS care. Information about volunteer motivations could help organizations plan recruitment messages, recruit volunteers whose motives match organizational goals and plan how to assist volunteers to satisfy these motives. This could reduce resentment and attrition among volunteers and improve programme sustainability. © The Author 2010; all rights reserved.

Odhiambo N.M.,University of South Africa
Energy Policy | Year: 2010

In this paper we examine the causal relationship between energy consumption and economic growth in three sub-Saharan African countries, namely South Africa, Kenya and Congo (DRC). We incorporate prices as an intermittent variable in a bivariate setting between energy consumption and economic growth-thereby creating a simple trivariate framework. Using the ARDL-bounds testing procedure, we find that the causality between energy consumption and economic growth varies significantly across the countries under study. The results show that for South Africa and Kenya there is a unidirectional causal flow from energy consumption to economic growth. However, for Congo (DRC) it is economic growth that drives energy consumption. These findings have important policy implications insofar as energy conservation policies are concerned. In the case of Congo (DRC), for example, the implementation of energy conservation policies may not significantly affect economic growth because the country's economy is not entirely energy dependent. However, for South Africa and Kenya there is a need for more energy supply augmentations in order to cope with the long-run energy demand. In the short-run, however, the two countries should explore more efficient and cost-effective sources of energy in order to address the energy dependency problem. © 2009 Elsevier Ltd. All rights reserved.

Padayachee K.,University of South Africa
Computers and Security | Year: 2012

This paper aims at surveying the extrinsic and intrinsic motivations that influence the propensity toward compliant information security behavior. Information security behavior refers to a set of core information security activities that have to be adhered to by end-users to maintain information security as defined by information security policies. The intention is to classify the research done on compliant information security behavior from an end-user perspective and arrange it as a taxonomy predicated on Self-Determination Theory (SDT). In addition, the relative significance of factors that contribute to compliant information security behavior is evaluated on the basis of empirical studies. The taxonomy will be valuable in providing a comprehensive overview of the factors that influence compliant information security behavior and in identifying areas that require further research. © 2012 Elsevier Ltd. All rights reserved.

Widgerow A.D.,University of South Africa
International Wound Journal | Year: 2013

As with all physiologic processes, chronic wounds are associated with unique intracellular and cellular/extracellular matrix (ECM) receptor types and signalling messages. These cellular receptors mediate responses of the epidermis to provisional wound matrix and change in form and number in cases of impaired wound healing. Integrins are the major cell-surface receptors for cell adhesion and migration and epidermal keratinocytes express several integrins that bind ECM ligands in provisional wound ECM. Integrin receptors and more particularly integrin clusters and focal adhesion points appear to influence epidermal and dermal cell matrix interactions, cell motility, cell phenotype and ultimate healing trajectory. In chronic wounds, a variety of changes in receptors have been identified: decreased integrin α5β1 receptors affect the integration of fibronectin and subsequent keratinocyte migration; integrin αvβ6 stimulate transforming growth factor (TGF)-β and may increase the susceptibility to ulceration and fibrosis; however, TGF-β signal receptors have been found to be dysfunctional in many chronic wounds; additionally receptor interactions result in increased senescent cells including fibroblasts, myofibroblasts and even keratinocytes - this produces a degradative ECM and wound bed and corrosive chronic wound fluid. The activation or inhibition of integrin receptors by various agents may provide an excellent means of influencing wound healing. This process offers an earlier intervention into the wound healing cascade promoting intrinsic healing and elaboration of growth factors and ECM proteins, which may be more cost effective than the traditional attempts at extrinsic addition of these agents. © 2012 The Author International Wound Journal © 2012 Blackwell Publishing Ltd and Inc.

Chetty S.,University of South Africa | Adewumi A.O.,University of South Africa
IEEE Transactions on Evolutionary Computation | Year: 2014

Annual crop planning (ACP) is an NP-hard type optimization problem in agricultural planning. It involves finding the optimal solution for the seasonal hectare allocations of a limited amount of agricultural land, among various competing crops that are required to be grown on it. This study investigates the effectiveness of employing three relatively new swarm intelligence (SI) metaheuristic techniques in determining the solutions to the ACP problem with case study from an existing irrigation scheme. The SI metaheuristics studied are cuckoo search (CS), firefly algorithm (FA), and glowworm swarm optimization (GSO). Solutions obtained from these techniques are compared with that of a similar population-based technique, namely, genetic algorithm (GA). Results obtained show that each of the three SI algorithms provides superior solutions for the case studied. © 1997-2012 IEEE.

University of South Africa | Date: 2013-11-14

A method and an apparatus for treating a fluid are disclosed. The apparatus includes a cylindrical chamber of non-magnetic material for holding a volume of fluid to be treated. The fluid contains a quantity of magnetic particles, preferably nanoparticles, having desired properties for treating the fluid. The apparatus includes a magnetic field generator for creating a non-static magnetic field within the chamber, thereby to induce motion in the magnetic particles within the chamber in use. The chamber has an inlet through which fluid to be treated can be introduced, and an outlet through which treated fluid can be removed from the chamber. Sets of windings are disposed concentrically about the chamber and arranged to create a rotating magnetic field within the chamber. Preferably the rotating magnetic field rotates in the opposite sense to swirling rotation of the fluid in the chamber. This enhances contact between the nano-particles and the fluid to be treated.

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