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Like a bolt from the blue : phthalocyanines in biomedical optics

  • Authors: Sekkat, N , Van den Berg, H , Nyokong, Tebello , Lange, N
  • Date: 2012
  • Subjects: Biomedical optics Fluorescence diagnosis Phthalocyanines NIR dyes Photodynamic therapy
  • Language: English
  • Type: Article
  • Identifier: vital:6597 , http://hdl.handle.net/10962/d1004346 , http://dx.doi.org/10.3390/molecules17010098
  • Description: The purpose of this review is to compile preclinical and clinical results on phthalocyanines (Pcs) as photosensitizers (PS) for Photodynamic Therapy (PDT) and contrast agents for fluorescence imaging. Indeed, Pcs are excellent candidates in these fields due to their strong absorbance in the NIR region and high chemical and photo-stability. In particular, this is mostly relevant for their in vivo activation in deeper tissular regions. However, most Pcs present two major limitations, i.e., a strong tendency to aggregate and a low water-solubility. In order to overcome these issues, both chemical tuning and pharmaceutical formulation combined with tumor targeting strategies were applied. These aspects will be developed in this review for the most extensively studied Pcs during the last 25 years, i.e., aluminium-, zinc- and silicon-based Pcs.
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  • Date Issued: 2012

The Revolutionary Road to Liberation

A possible relation between dietary zinc and cAMP in the regulation of tumour cell proliferation in the rat

  • Authors: Skeef, Noel S , Duncan, John R
  • Date: 1988
  • Language: English
  • Type: Article
  • Identifier: vital:6473 , http://hdl.handle.net/10962/d1006154 , http://dx.doi.org/10.1079/BJN19880052
  • Description: The possibility of an effect of zinc on the rate of tumour cell division, mediated through a regulation of cellular cAMP concentration, was investigated in the present study in rats. Dietary Zn deficiency (< 1·5 mg Zn/kg) but not Zn excess (500 mg Zn/kg) resulted in an increased cAMP concentration in transplanted hepatoma cells. Neither treatment had any effect on the cAMP concentration in regenerating liver or normal resting liver. Both the deficient and excess Zn diets resulted in a small reduction in tumour growth (not statistically significant). The results seem to indicate that the relation investigated in the present study does not apply in the cell line used.
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  • Date Issued: 1988

Application of satellite-derived rainfall estimates to extend water resource simulation modelling in South Africa

  • Authors: Sawunyama, Tendai , Hughes, Denis A
  • Date: 2008
  • Language: English
  • Type: text , Article
  • Identifier: vital:7089 , http://hdl.handle.net/10962/d1012419
  • Description: Spatially interpolated rainfall estimates from rain-gauges are widely used as input to hydrological models, but deriving accurate estimates at appropriate space and time scales remain a major problem. In South Africa there has been a gradual decrease in the number of active rain-gauges over time. Satellite-based estimates of spatial rainfall are becoming more readily available and offer a viable substitute. The paper presents the potential of using Climate Prediction Center African daily precipitation climatology (CPCAPC) satellite-based datasets (2001-2006) to drive a Pitman hydrological model which has been calibrated using gauge-based rainfall data (1920-1990). However, if two sources of rainfall data are to be used together, it is necessary to ensure that they are compatible in terms of their statistical properties. A non-linear frequency of exceedance transformation technique was used to correct the satellite data to be more consistent with historical spatial rainfall estimates. The technique generated simulation results for the 2001 to 2006 period that were greatly improved compared to the direct use of the untransformed satellite data. While there remain some further questions about the use of satellite-derived rainfall data in different parts of the country, they do seem to have the potential to contribute to extending water resource modelling into the future.
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  • Date Issued: 2008

Continuous support for women during childbirth (Review)

  • Authors: G Justus Hofmeyr2
  • Date: 2017
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/11260/5658 , vital:44621
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The relationship between double taxation agreements and the provisions of the South African Income Tax Act

  • Authors: Stack, Elizabeth M
  • Date: 2014
  • Subjects: To be catalogued
  • Language: English
  • Type: Article
  • Identifier: vital:21102 , http://hdl.handle.net/10962/6384 , http://journals.co.za/content/jefs/7/2/EJC157823
  • Description: This article investigates the legal status of Double Taxation Agreements, and the relationship between Double Taxation Agreements, which are concluded in terms of section 108 of the Income Tax Act, and the provisions of the Income Tax Act (taking into account the provisions of the Constitution, and the national and international rules for the interpretation of statutes). An important conclusion reached was that as the Vienna Convention on the Law of Treaties represents customary international law and as such forms part of South African law, the principles contained in the treaty should be taken into account when interpreting South African legislation (including Double Taxation Agreements).The final conclusion of the research was that Double Taxation Agreements have a dual nature – forming part of domestic legislation and being classified as international agreements. The provisions of the Double Taxation Agreement should be taken as overriding any conflicting legislation in the Income Tax Act.
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  • Date Issued: 2014

Sculpting with fire: celebrating ephemerality at AfrikaBurn 2015 in the Tankwa Karoo, South Africa

  • Authors: Steele, John
  • Date: 2015
  • Language: English
  • Type: text , Article
  • Identifier: http://hdl.handle.net/11260/957 , vital:30075
  • Description: Land art, and some installation art, is usually aimed at relatively temporarily manipulating the surface of the earth. AfrikaBurn takes place annually in the near-desert of the Tankwa Karoo, South Africa. It is a communal event unique to Africa, and manifests as a fleeting week-long series of interventions in the natural environment, partially aimed at creating and then actively destroying free-standing public sculptures, some of which are huge and intricate. AfrikaBurn gives any one of the thousands of participants an opportunity to be inspired on any scale to generate artworks that take into account a principle that no debris whatsoever is left behind on the surface of the earth after a week-long celebration of creative energies. Unlike, for instance, an artwork built on the edge of the Indian Ocean in the Eastern Cape, where rough tidal seas would ensure gradual destruction, at AfrikaBurn, the sacrificial method of choice is controlled rapid burning, under the direction of a specified firemaster. This paper seeks to unbundle some aspects of land and installation art in Southern Africa with specific reference to AfrikaBurn 2015 events and anti-fracking initiatives. This is within a context that takes into account recognition that even seemingly durable public sculptures are subject to change and may even physically disappear with the passing of time.
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  • Date Issued: 2015

Will the real custodian of natural resource management please stand up

  • Authors: Shackleton, Charlie M
  • Date: 2009
  • Language: English
  • Type: Article
  • Identifier: vital:6657 , http://hdl.handle.net/10962/d1007076
  • Description: South Africa is the custodian of an immense wealth of biodiversity resources, and is estimated to be the third most biodiverse country in the world. At the ecosystem level this biodiversity supports the production of goods and services used by us all; water, air, soil fertility, wood, food, etc. At a more local level the harvesting of numerous natural resources provides consumptive products for millions of poor South Africans, as well as income for equally significant numbers.Consumption of and trade in these resources is the very mainstay of their well-being, and crucial in preventing deeper poverty levels. For example, despite massive improvements in the provision of electricity, most rural and a significant proportion of urban South Africans continue to use fuelwood as a key energy source for cooking (e.g. 65% of electrified households in the urban areas of Makana municipality, and 92% of households in the rural areas of Bushbuckridge); approximately 75% of the population use medicinal plants for medicinal or cultural reasons; and millions of urban and rural households make use of wild edible herbs. With such high demand for these resources, it is not unsurprising that there are large and established trade networks spanning local, regional, national and, for some resources (e.g. specific medicinal plants, mopane worms), international boundaries. The total value of this trade is unknown, and unrecorded in local or national economic or GDP statistics. It certainly equates to billions of rands per year. The direct-use and trade values are substantial and provide a cost saving to the State. Where biodiversity resources are overused or exhausted, people have to purchase alternatives, which reduces their scarce cash resources, thereby increasing their likely dependency on State welfare grants.
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  • Date Issued: 2009

The Educational Journal

The invasive ‘mothcatcher’ (Araujia sericifera Brot.; Asclepiadoideae) co-opts native honeybees as its primary pollinator in South Africa

  • Authors: Coombs, Gareth , Peter, Craig I
  • Date: 2010
  • Language: English
  • Type: Article
  • Identifier: vital:6510 , http://hdl.handle.net/10962/d1005937
  • Description: Background and aims: Successful invasive plants such as Araujia sericifera usually either are capable of automatic self-pollination or maintain pollinator services by having generalized pollination systems to make use of local pollinators in the invaded range. Alternatively, plants must co-opt new pollinators with similar morphology to native pollinators or reproduce asexually. We aimed to document the pollination biology of A. sericifera in South Africa. Given the success of this species as an invader, we predicted that sexual reproduction occurs either through self-pollination or because A. sericifera has successfully co-opted native insect pollinators. Methodology: We examined the pollination biology of the South American A. sericifera in South Africa. We documented the effective pollinators including a comparison of the efficacy of nocturnal versus diurnal pollinators as well as the breeding system and long-term natural levels of the pollination success of this species. Principal results: We found that native honeybees (Apis mellifera) were the main pollinators of A. sericifera in South Africa. Visiting moths are unimportant pollinators despite being attracted by the pale colour and nocturnal scent of the flowers. Plants from the Grahamstown population were incapable of autonomous self-pollination but pollinator-mediated self-pollination does occur. However, the highest fruit initiation resulted from out-crossed pollination treatments. The high pollen transfer efficiency of this species was comparable to other hymenopteranpollinated exotic and native milkweeds, suggesting that A. sericifera maintains pollinator services at levels experienced by indigenous asclepiad species. Conclusions: Araujia sericifera reproduces successfully in South Africa due to a combined ability of this species to attract and exploit native honeybees as its pollinators and of individual plants to set fruit from pollinator-mediated self-pollination.
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  • Date Issued: 2010

The Educational Journal

  • Date: 2001-06
  • Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
  • Language: English
  • Type: text , Article
  • Identifier: http://hdl.handle.net/10948/38599 , vital:34838 , Bulk File 7
  • Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
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  • Date Issued: 2001-06

The Blue Notes

The Educational Journal

An approach to anaemia diagnosis – concerns in primary care

  • Authors: D O’Mahony , M Mntonintshi
  • Date: 2017
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/11260/5616 , vital:44615
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Traveling without passport

  • Authors: Nighthawk
  • Language: French
  • Type: Article
  • Identifier: vital:13624 , http://hdl.handle.net/10962/d1012499
  • Description: Photocopied article in French about 2 Piano solo performances of Chris McGregor at la Salle Bleue in Toulouse, France.
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The need for an inland fisheries policy in South Africa : a case study of the North West Province

  • Authors: Weyl, Olaf L F , Potts, Warren M , Rouhani, Q
  • Date: 2007
  • Language: English
  • Type: Article
  • Identifier: vital:6769 , http://hdl.handle.net/10962/d1008056
  • Description: In contrast to many other African countries, inland fisheries in South Africa are poorly developed and the fish populations in many of the country’s 3 000 major dams are under-utilised. While the primary purpose South Africa’s dams is to supply water for domestic and agricultural use, there has been an increasing realisation that their fish populations could make a contribution to food security through the establishment of capture fisheries. Historically, the fish in most South African dams have primarily been utilised for recreational fishing purposes, as subsistence use was criminalised by the apartheid regime in all waters except in the former homeland areas. This legacy persists as many of South Africa’s rural communities do not have a fishing tradition and there is a lack of an institutional framework to facilitate managed and sustainable access to the fish resource in inland waters. Current utilisation of many inland dams is often complicated by the existence of multiple authorities and interest groups, often with competing agendas. As a result, the economic potential of these water bodies is unknown and often grossly underutilised. Our study outlines a case study of fisheries resources in the North West Province of South Africa that could be used for the creation of income and food security for local communities through the development of subsistence, commercial, and recreational fisheries. The study identifies the lack of guidelines for the development of inland fisheries and the lack of an inland fisheries policy, both at the provincial and national level, as major bottlenecks for the sustainable development of these resources and outlines possible focal areas for intervention.
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  • Date Issued: 2007

Assessing the potential for biological invasion - the case of Ammophila arenaria in South Africa

  • Authors: Hertling, Ursula M , Lubke, Roy
  • Date: 2000
  • Language: English
  • Type: Article
  • Identifier: vital:6518 , http://hdl.handle.net/10962/d1005947
  • Description: Many plants, especially woody species, introduced into South Africa for ornamental or commercial purposes, have become invasive in a number of habitats. Because of the risk of an invasion of coastal dunes by yet another species, the European dune grass Ammophila arenaria, used as a dune stabilizer, is assessed using lists of attributes of invasive species and invasible ecosystems. It is impossible to predict plant invasions, but both invasive species as well as invaded ecosystems are often characterized by certain attributes which facilitate invasions. Many of the species attributes connected with invasion appear to apply to A. arenaria. Above all, the grass is characterized by ecological tolerance and vigorous rhizomatous reproduction. An important site attribute connected with invasion is an evolutionary history with isolation patterns, which applies to the South African Cape coast. We conclude also on the basis of the overseas experience, that the potential for A. arenaria to become invasive needs urgent investigation in the South African context.
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  • Date Issued: 2000

The Educational Journal

Mongezi Feza

  • Authors: Unknown
  • Subjects: McGregor, Chris--1936-1990 , Feza, Mongezi
  • Language: English
  • Type: Article
  • Identifier: vital:13729 , http://hdl.handle.net/10962/d1012742
  • Description: Photocopied article from the Jazz Magazine of London about Mongezi Feza's death. There is a caricature of Mongezi Feza playing the trumpet with this article.
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Photoinactivation of Candida albicans and Escherichia coli using aluminium phthalocyanine on gold nanoparticles

  • Authors: Mthethwa, Thandekile , Nyokong, Tebello
  • Language: English
  • Type: Article
  • Identifier: vital:7298 , http://hdl.handle.net/10962/d1020364
  • Description: The conjugates of aluminium phthalocyanine (complex 1) with gold nanorods (complex 1–AuNRs) and bipyramids (complex 1–AuBPs) showed improved singlet oxygen quantum yields of 0.23 and 0.24, respectively, compared to that of complex 1 alone at 0.12. Complex 1 and its conjugates were used for the photoinactivation of fungi (C. albicans) and bacteria cells (E. coli). The Q band absorbances were the same for the Pc alone and when conjugated to AuNPs. The efficiency of these conjugates was evaluated by measuring the log reduction of the microorganisms (C. albicans and E. coli) after irradiation with visible light in the presence of photosensitizers. Aluminium phthalocyanine alone showed log 1.78 and log 2.51 reductions for C. albicans and E. coli respectively. However, the conjugates showed higher photosensitization with log 2.08 and log 3.34 for C. albicans and E. coli, respectively using 1–AuBPs. For complex 1–AuNRs log 2.53 and log 3.71 were achieved for C. albicans and E. coli respectively. The statistical analysis of the results showed that the enhanced photoinactivation observed in both microorganisms was irrespective of the shape of the nanoparticles conjugated. Photoinactivation of C. albicans was less than that of E. coli even though a higher concentration of complex 1 or its conjugates was used in C. albicans. , Original publication is available at http://dx.doi.org/10.1039/C4PP00315B , Arbortext Advanced Print Publisher 9.1.520/W Unicode , Acrobat Distiller 10.0.0 (Windows); modified using iTextSharp 5.5.1 �2000-2014 iText Group NV (AGPL-version); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
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