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Tetracarboxylic acid cobalt phthalocyanine SAM on gold: Potential applications as amperometric sensor for H2O2 and fabrication of glucose biosensor

  • Authors: Mashazi, Philani N , Ozoemena, Kenneth I , Nyokong, Tebello
  • Date: 2006
  • Language: English
  • Type: Article
  • Identifier: vital:6578 , http://hdl.handle.net/10962/d1004141
  • Description: This report describes the applications of cobalt tetracarboxylic acid phthalocyanine (CoTCAPc) self-assembled monolayer (SAM) immobilized onto a preformed 2-mercaptoethanol (Au-ME) SAM on gold surface (Au-ME-CoTCAPc SAM) as a potential amperometric sensor for the detection of hydrogen peroxide (H[subscript 2]O[subscript 2]) at neutral pH conditions. The Au-ME-CoTCAPc SAM sensor showed a very fast amperometric response time of approximately 1 s, good linearity at the studied concentration range of up to 5 μM with a coefficient R² = 0.993 and a detection limit of 0.4 μM oxidatively. Also reductively, the sensor exhibited a very fast amperometric response time (~1 s), linearity up to 5 μM with a coefficient R² = 0.986 and a detection limit of 0.2 μM. The cobalt tetracarboxylic acid phthalocyanine self-assembled monolayer was then evaluated as a mediator for glucose oxidase (GOx)-based biosensor. The GOx (enzyme) was immobilized covalently onto Au-ME-CoTCAPc SAM using coupling agents: N-ethyl-N(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS), and the results demonstrated a good catalytic behavior. Kinetic parameters associated with the enzymatic and mediator reactions were estimated using electrochemical versions of Lineweaver–Burk and Hanes equation, and the stability of the sensor was tested. The biosensor (Au-ME-CoTCAPc-GOx SAM) electrode showed good sensitivity (7.5 nA/mM) with a good detection limit of 8.4 μM at 3σ, smaller Michaelis–Menten constant (4.8 mM from Hanes plot) and very fast response time of approximately 5 s.
  • Full Text:
  • Date Issued: 2006

The geology and geochemistry of the Palaeoproterozoic Makganyene diamictite

  • Authors: Polteau, S , Moore, John M , Tsikos, Harilaos
  • Date: 2006
  • Language: English
  • Type: Article
  • Identifier: vital:6740 , http://hdl.handle.net/10962/d1007556
  • Description: The Palaeoproterozoic Earth experienced a global glacial event at 2400 Ma that occurred during the transitional period from anoxic to aerobic conditions in the atmosphere and oceans. The Transvaal Supergroup in the Griqualand West Basin, South Africa, hosts glacial deposits and associated major iron and manganese deposits that are apparently related to these global changes. The focus of this study is to assess the stratigraphy and geochemistry of the glaciogenic Makganyene Formation, in order to constrain its palaeoenvironmental settings. The Makganyene Formation forms the base of the Postmasburg Group and has been regarded as resting on an erosive regional unconformity throughout the Northern Cape Province. Systematic regional field observations and regional mapping carried out during this study demonstrate that this stratigraphic relationship is not universal. The Makganyene Formation is, in fact, conformable with underlying formations of the Koegas Subgroup in the deep southern Prieska basin and rests on an unconformity only on the shallow Ghaap platform to the north-east. The Makganyene Formation displays lateral facies changes that reflect the palaeogeography of the study area, and the advance and retreat of ice sheets/shelves. Geochemical investigations of glacial strata of the Makganyene Formation demonstrate that underlying banded iron formations of the Transvaal Supergroup acted as the main clastic source for the diamictite detritus. Geographic variations in bulk composition of the diamictites correlate well with field observations, and show that sorting processes were controlled largely by the morphology of the palaeobasin. Carbon isotope results emphasize the transitional nature of the Makganyene Formation in terms of the environmental conditions that resulted in widespread global glaciation in the Palaeoproterozoic. On the basis of the above geological evidence, it is proposed that the Transvaal Supergroup in the Northern Cape Province represents a continuous depositional event that lasted approximately 250 Ma and hence provides a unique opportunity for assessing the transitional changes experienced by the Palaeoproterozoic Earth.
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  • Date Issued: 2006

New Unity Movement Bulletin

Art for the masses? Justification for the public support of the arts in developing countries – two arts festivals in South Africa

  • Authors: Snowball, Jeanette D
  • Date: 2005
  • Language: English
  • Type: Article
  • Identifier: vital:6077 , http://hdl.handle.net/10962/d1006127 , http://dx.doi.org/10.1007/s10824-005-5064-5
  • Description: In the New South Africa, as in other developing countries, the equitable distribution of public resources is a priority. The case for public support of the arts is thus difficult to make because it has been shown and borne out by South African research, that arts audiences tend to represent the better educated, more prosperous minority of society, not the majority of the very poor, mainly African-origin population. Using data from willingness to pay studies conducted at two South African arts festivals, this paper shows that, when the positive externalities provided by the arts are included in their valuation, it can be shown that both high and low income earners benefit. However, as suggested by Seaman (2003), it is also found that some of what the WTP figure is capturing is current and expected future economic benefit from the event.
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  • Date Issued: 2005

Unconscious influences on discourses about consciousness : ideology, state-specific science and unformulated experience

  • Authors: Edwards, David J A
  • Date: 2005
  • Language: English
  • Type: Article
  • Identifier: vital:6226 , http://hdl.handle.net/10962/d1007776
  • Description: Discussions about consciousness are complicated by the fact that participants do not share a common underlying “ordinary” consciousness. Everyday experience is founded on what Teasdale calls implicational cognition, much of which is not verbally formulated. An unacknowledged aspect of debate is individuals’ attempts to negotiate the expression of their unformulated experience. This is further complicated by the way in which a discourse, based on particular ontological assumptions, exercises an ideological control which limits what underlying aspects of experience can be formulated at all. Tart’s concept of state specific sciences provides a framework within which the role of unformulated experience can be acknowledged and taken into account. Unless this is done, debates will be vitiated by participants engaging in ideological struggles and talking at cross-purposes.
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  • Date Issued: 2005

Pre-emigration reflections : Afrikaans speakers moving to New Zealand

  • Authors: De Klerk, Vivian A , Barkhuizen, Gary P
  • Date: 2004
  • Language: English
  • Type: Article , text
  • Identifier: vital:6138 , http://hdl.handle.net/10962/d1011590
  • Description: This article reports on the pre-emigration reflections of 15 Afrikaans speakers, all of whom were in the final stages of preparing to emigrate to New Zealand. The study explores the linguistic histories of the participants, their attitudes to their mother tongue (Afrikaans) and to English, and their views on South Africa's language policy and how it has influenced their decisions to leave the country. The paper also offers a view on possible long-term linguistic outcomes for these families.
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  • Date Issued: 2004

New Unity Movement Bulletin

Dynamic run-time application development using CORBA objects and XML in the field of distributed GIS

  • Authors: Preston, Michael , Clayton, Peter G , Wells, George C
  • Date: 2003
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/430500 , vital:72695 , https://doi.org/10.1080/1365881021000026557
  • Description: The research presented describes our approach to enabling content developers and end-users to create and/or customise distributed GIS applications dynamical-ly at run-time through the incorporation of GIS services, implemented as stand-alone components or CORBA Objects, with a specialised XML descriptor. It also looks at some of the design considerations that must be dealt with by both the client-application developer as well as the service developer, including the GIS service description, associated GUI and help system.
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  • Date Issued: 2003

Intervention in Bosnia-Herzegovina: lessons of peace‐maintenance for Africa?

  • Authors: Bischoff, Paul, 1954-
  • Date: 2003
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/161365 , vital:40620 , DOI: 10.1080/10220460309545430
  • Description: The Bosnian model is potentially a useful model for the development of a new strategic framework for African conflicts, particularly in situations where international organisations such as the United Nations are overstretched and regional organisations wish to take charge of peacebuilding operations.
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  • Date Issued: 2003

Revision of the genus Xiphoscelis Burmeister 1842 (Coleoptera Scarabaeidae Cetoniinae), with description of two new species and notes on its phylogeny and ecology

  • Authors: Perissinotto, Renzo , Villet, Martin H , Stobbia, P
  • Date: 2003
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/442293 , vital:73973 , https://doi.org/10.1080/03946975.2003.10531184
  • Description: Recent field work has shown that the genus Xiphoscelis Burmeister 1842 contains at least three species. The type species is re-described, and two new species are described, based on adult morphology. The distribution of all three Xiphoscelis species is mapped, and a phylogeny is proposed for the genus. Ecological data are presented and discussed in the context of the previously-reported association of members of this genus with termites.
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  • Date Issued: 2003

Teenage pregnancy and the construction of adolescence : scientific literature in South Africa

  • Authors: Macleod, Catriona I
  • Date: 2003
  • Language: English
  • Type: Article
  • Identifier: vital:6258 , http://hdl.handle.net/10962/d1007876 , http://journals.sagepub.com/doi/10.1177/0907568203104003
  • Description: The depiction of teenage pregnancy as a social problem relies on the assumption of adolescence as a separable stage of development. Utilising a Derridian framework, I analyse how the dominant construction of adolescence as a transitional stage: (1) acts as an attempt to decide the undecidable (viz. the adolescent who is neither child nor adult, but simultaneously both) – an attempt which collapses in the face of teenage pregnancy; (2) relies on the ideal adult as the endpoint of development, and (3) has effects in terms of gendered and expert/parent/adolescent power relations.
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  • Date Issued: 2003

The geochemical structure of the Insizwa lobe of the Mount Ayliff complex with implications for the emplacement and evolution of the complex and its Ni-sulphide potential

  • Authors: Marsh, Julian S , Allen, P , Fenner, N
  • Date: 2003
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/150556 , vital:38984 , https://doi.org/10.2113/106.4.409
  • Description: Detailed petrographic, modal and geochemical studies on a number of deep boreholes (exceeding 1.2 km in some instances) along the southeastern margin of the Insizwa lobe of the Mount Ayliff Complex reveal the existence of a geochemical stratigraphy in the mafic intrusive rocks.
  • Full Text: false
  • Date Issued: 2003

New Unity Movement Bulletin

Workers Tribune

  • Authors: NACTU
  • Date: May 2001
  • Subjects: NACTU
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/167897 , vital:41520
  • Description: Nactu, the second largest trade union federation with a membership of more than 500 000 workers from across various sectors, publishes this month its new baby. Workers Tribune, a monthly magazine that will communicate the federation's message to its members and other interested parties. It was not by accident that the birth of this important publication should coincide with May Day. For Nactu, May Day is the embodiment of workers' and peoples' struggles that has culminated in the freedom that South Africa enjoys today. We also know that these struggles occurred in an unfriendly, and often hostile environment, with many of the liberation heroes and heroines laying down their lives for the love of freedom and justice. We now enjoy democracy and freedom, and we must work hard at preserving it. We must always be mindful that it is easy to abuse freedom, and so we must strenuously be on the lookout for tendencies that seek to undermine freedom. We may have a new political order in our country, but there can be no question that the working class is still facing new challenges against capital, even black bosses. We still live in an environment that creates tensions between the working class and the bosses. We still have thousands of our comrades who have been retrenched because of the desire by bosses to realise big profits. And so, the struggle for workers' complete emancipation from tyranny is far from over. All bosses, including some we shared pain and abuse in the apartheid trenches, are capable of reverting to old ways. We must not forget that, like the erstwhile bosses of the apartheid era, they operate within an environment that is determined from outside,, and so they have to play the game according to pre-determined rules. The emergence of turncoats is on the increase. And for reasons I have alluded to, that should not surprise us. The trade union movement should increasingly prepare itself for other battles. But we should also empower ourselves with knowledge, so that when we dialogue with the bosses we raise compelling arguments. Slogans qlone do not work. We need to develop intellect as well. And so in this issue, Comrade Cunningham Ngcukana begins the process of teaching, and mental empowerment. He helps his readers to have a better understanding of what globalisation is all about, explaining that it is more profitable for unions to have profound appreciation of the workings of this system if they have to use it to their advantage. Ngcukana also writes about May Day. He tells us about the origins of this day. It is history we need because it is both informative and inspiring. A fine and commendable work by the general secretary of Nactu. There is also an article on gender equality in the workplace. Brenda Modise wrote it for us, and do read and enjoy it. To break the heaviness of the magazine, we also run a variety of pictures that seek to introduce to readers some of Nactu's leaders. We believe that it is important that you know your leaders in the trade union movement. Most importantly, however, we want to create a dialogue between ourselves and readers. Do, therefore, send us letters, commenting on various issues raised in this number. We hope to be of service to you. Do have a nice read.
  • Full Text:
  • Date Issued: May 2001

PROCEDO - Mouthpiece of the Public and Allied Workers Union of South Africa

  • Authors: PAWUSA
  • Date: July 2000
  • Subjects: PAWUSA
  • Language: English, Afrikaans
  • Type: text
  • Identifier: http://hdl.handle.net/10962/113966 , vital:33858
  • Description: Sedert 1992, toe die politieke regskikking van die land begin gebeur het (Goddank), het die rooilig-tyd by ons verbygegaan en, met die verkiesing in 1994, het 'n wonderlike groenlig*tydvak vir ons almal aangebreek. Politiek, en veral party-politiek hierby uitgesluit, sal geen regdenkende mens horn weer wil terugbegeef in die tyd toe demokrasie 'n hoi woord was en die land effektief regeer is deur een magtige kabaal met hordes gedienstige rade, geheime komitees en baantjies-vir-boeties- organisasies nie. Suid-Afrika het destyds, sedert die verkiesing in 1948, progressief 'n minder lekker plek begin raak om in te bly - veral vir party van die groeperings. Dit het hoofsaaklik gebeur, soos dit in Engels gestel word, weens "power corrupts, absolute power corrupts absolutely". Ek sluit nie by hierdie stelling enige spesifieke persone in nie; ek maak slegs in die bree die stelling oor dit waar is van enige situasie. Oor mens maar altyd mens bly en versoekings vo|op is. The previous dispensation was one where, in our public labour environment, one union (or association as it was then known) was closely aligned to the government of the day. They were soon disempowered, simply because it is difficult to disagree if your basic philosophies are similar to those you are supposed to oppose. Eventually, it was not at all strange to find that salary increases where dished out just before an election, simply to be sucked up the following year by inflation,:Which was fairly out of control at the time.
  • Full Text:
  • Date Issued: July 2000

New Unity Movement Presidential Address

New Unity Movement Bulletin

  • Date: 1999-06
  • Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10948/31086 , vital:31317 , Bulk File 7
  • Description: The Bulletin was the official newsletter of the New Unity Movement. It was published about twice a year and contained articles reflecting the organisation's views on resistance to the Apartheid government.
  • Full Text: false
  • Date Issued: 1999-06

Beyond the development impasse : the role of local economic development and community self-reliance in rural South Africa

  • Authors: Binns, Tony , Nel, Etienne L
  • Date: 1999
  • Language: English
  • Type: Article
  • Identifier: vital:6673 , http://hdl.handle.net/10962/d1006647
  • Description: The failure of successive generations of imported, Western development strategies and projects to deliver meaningful reductions in poverty and achieve basic needs in Africa, has provoked a deep questioning of Western concepts and methodologies of development. Non-governmental organisations and development practitioners are increasingly focusing their attention on strategies which build upon local knowledge, skills and resources. The concepts of ‘self- reliance’ and local economic development are examined in the context of development challenges which face Africa. This is followed by a detailed case study of local economic development in the rural Mpofu District of the former Ciskei Homeland, which was incorporated into the Eastern Cape province of South Africa with the demise of apartheid in 1994.
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  • Date Issued: 1999

South Africa's "Rainbow People", national pride and happiness

  • Authors: Moller, Valerie , Dickow, H , Harris, M
  • Date: 1999
  • Language: English
  • Type: Article
  • Identifier: vital:7117 , http://hdl.handle.net/10962/d1010751
  • Description: Since the first free elections were held in April 1994, South Africans are popularly known as the ''rainbow people''. The paper inquires whether South Africans who experienced pride in their nation in the first years of democracy also perceived a greater sense of subjective well-being. It is proposed that national pride in post-apartheid South Africa might be fused with or work through self-esteem to lift levels of happiness. The paper traces the history of the new integrating civil religion of the rainbow people and the acceptance of the rainbow as a political symbol of unity among the diverse people of South Africa immediately after the 1994 elections and two years later. The proposed link between national pride and happiness was explored with data from two independent national surveys, the 1995 South African World Values Survey conducted by Markinor and a June 1996 MarkData syndicated omnibus survey. The study found that the appeal of the rainbow as political symbol was inclusive of all groups in society and that feelings of national pride and support for the rainbow ideal were positively associated with subjective well-being. As indicated by intensity and frequency measures, the majority of South Africans were proud of their country and could name a national achievement that inspired pride. Better-off South Africans tended to be happier and more satisfied with life but less proud, while the poor were less happy but fiercely proud of their country. Results suggest that belief in South Africa’s ''rainbow nation'' ideal may have assisted in boosting happiness during the transition to a stable democracy, thereby preventing alienation among the losers under the new political dispensation. Supporters of the ideal of the rainbow nation were more optimistic than others about the future of their country.
  • Full Text:
  • Date Issued: 1999

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