Afrikaans en taalpolitiek: enkele voorlopige opmerkings

Afrikaans and the linguistic plitics: Some prelimanery remarks. The purpose of this article is to indicate to what extent the Afrikaans language has been politicised in South Africa since the advent of Afrikaner nationalism in the late nineteenth century . Afrikaans and apartheid are two cornerstones of Afrikaner nationalism and in the period between 1948 and 1976 Afrikaans was perceived to be the medium through which apartheid was implemented. The 197G Soweto Riots resulted in widespread rejection of Afrikaans , but since the early 1980's a new movement, popularly referred to as alternative Afrikaans has developed. This movement is set on giving a new or alternative ideological content to Afrikaans indirect contrast to that of establishment Afrikaans . Despite profound differences with regard to the ideological content and the aims of these two varieties of Afrikaans , there are also certain similarities between them

Beginsels en metodes vir die bepaling van die ouderdom van hominied fossiele en hulle vindplekke

Principles and methods used for the determination of the age of hominid fossils and their discovery sites Paleoanthropologists have an array of physical dating methods developed by researchers in the physical sciences. These techniques permit students of hominid evolution and associated culture to have increasing confidence that the evidence of past hominid morphology as expressed by the fossil finds is being placed in the correct chronological order. This article explains in a simple and straightforward way the evidence and logic that have led scientists to conclude that hominid fossils are not a few thousand years but at least several million years old. The main focus is on the 40Ar/ 39Ar technique, but other absolute dating techniques such as carbon-14, uranium-thorium-lead and radiocalcium are also reviewed. Relative dating methods are briefly discussed together with paleomagnetism (geomagnetism), optic stimulated luminescence and amino acids

Ghost crabs on a treadmill: Oxygen Uptake and Haemocyanin Oxygen Affinity

Ghost crabs Ocypode ceratophthalmus were exercised on a specially constructed treadmill. At a running speed of 13,3 cm s-1, most crabs ran for 2 h before getting fatigued. At this speed the oxygen consumption rate (MO2) was measured in time intervals for a total of 52 min. For exercised crabs the MO2 values are about eight times higher (28,5 ± 5.0 mmol l-1kg-1h-1 compared with the values (3,5 ± 0,4 mmol l-1kg-1h-1) for resting crabs. One hour after the exercising bout, the MO2 values were not back to normal resting values. The l-lactate levels in the haemolymph increase to 20,7 (± 4,8) mmol l-1 after 20 min exercise, whilst the pH decreases from 7,91 (± 0,05) to 7,71 (± 0,08). For resting crabs pre-branchial PCfe (venous) is 35,9 (± 5,6) mmHg, total carbon dioxide concentration (Ceo, tot.) 22,6 (± 2,6) mmol l-1, l-lactate 0,68 (±0,5) mmol l-1; haemocyanin oxygen capacity (Cmax/Hcyo) 1,50 (± 0,11) mmol l-1; haemocyanin concentration 99,3 (± 21) mg ml-1and haemolymph oxygen content 4,11 ml O2 100 ml-1haemolymph. Haemolymph from resting crabs has P50 values of 4,5 (± 1,0) mmHg, while for exercised crabs it is 10,0 (±0,8) mmHg. Gel-chromato-graphed haemolymph increased the oxygen affinity of the haemocyanin to 1,30 (± 0,1) mmHg, an indication of the presence of oxygen affinity modulators in the haemolymph. A decrease in the pH of the haemolymph has a greater effect on oxygen affinity compared with the effects from either CO2 or l-lactate. Hill-plot analysis of both native and gel-chromatographed haemolymph reveal that co-operativity (n) of the oxygen-binding sites in the haemocyanin sub-units increases to a value of 4 with a corresponding decrease in oxygen affinity. This effect has the result that large amounts of O2 can be suddenly released by the haemocyanin to tissues such as muscle and ganglia for immediate mitochondrial use

Oorlewing van die skerpioen <i>Opistophthalmus pugnax</i> (Scorpionidae) ná blootstelling aan ’n letale dosis SO₂-gas

<span>Skerpioene is bekend vir hul aanpasbaarheid by toestande in ’n droë habitat, min voedsel en radioaktiewe bestraling. Niks is bekend oor hul aanpasbaarheid by skadelike gasse nie. Resultate van hierdie eksperiment by </span><em>Opistophthalmus pugnax </em><span>bewys dat hulle ’n hoë dosis van 1000 dele per miljoen SO</span>₂<span> kan oorleef wat nie die geval is by die mens nie. Byvoorbeeld, die suurstofverbruikskoers neem eerder toe van 4.16 µmol/g</span>^-1<span>uur</span>^-1<span>na 7.69 µmol/g</span>^-1<span>uur</span>^-1<span>, een uur ná blootstelling aan SO</span>₂<span>. Veertig minute na blootstelling was die ṀO</span>₂<span> steeds bykans twee keer hoër in vergelyking met die ṀO</span>₂<span> aan die begin. Hierdie bevinding moet deur verdere eksperimente nagevors word, veral wat die rol van spirakulumsluiting speel by blootstelling aan SO</span>₂<span>.</span

Total ionizing dose and single event upset testing of flash based field programmable gate arrays

The effectiveness of implementing field programmable gate arrays (FPGAs) in communication, military, space and high radiation environment applications, coupled with the increased accessibility of private individuals and researchers to launch satellites, has led to an increased interest in commercial off the shelf components. The metal oxide semiconductor (MOS) structures of FPGAs however, are sensitive to radiation effects which can lead to decreased reliability of the device. In order to successfully implement a FPGA based system in a radiation environment, such as on-board a satellite, the single event upset (SEU) and total ionizing dose (TID) characteristics of the device must first be established. This research experimentally determines a research procedure which could accurately determine the SEU cross sections and TID characteristics of various mitigation techniques as well as control circuits implemented in a ProASIC3 A3P1000 FPGA. To gain an understanding of the SEU effects of the implemented circuits, the test FPGA was irradiated by a 66MeV proton beam at the iTemba LABS facility. Through means of irradiation, the SEU cross section of various communication, motor control and mitigation schemes circuits, induced by high energy proton strikes was investigated. The implementation of a full global triple modular redundancy (TMR) and a combination of TMR and a AND-OR multiplexer filter was found to most effectively mitigate SEUs in comparison to the other techniques. When comparing the communication and motor control circuits, the high frequency I2C and SPI circuits experienced a higher number of upsets when compared to a low frequency servo motor control circuit. To gain a better understanding of the absorbed dose effects, experimental TID testing was conducted by irradiating the test FPGA with a cobalt-60 (Co-60) source. An accumulated absorbed dose resulted in the fluctuation of the device supply current and operating voltages as well as resulted in output errors. The TMR and TMR filtering combination mitigation techniques again were found to be the most effective methods of mitigation

Multi-Agent Communication and Collaboration

Degree: Master of Science in Engineering Department: EngineeringMulti-Agent Systems are becoming a popular paradigm for many engineering applications. However, there is still much research to be performed in this fast growing field. In this thesis, the effect of learning in multi-agent systems on communication and collaboration between agents is investigated. This research focuses on agents learning local cooperative behaviour from a centralised agent, as well as using learning to reduce the amount of communication between agents that use negotiation to achieve their goals. A simple test problem is formulated in MATLAB. The effect of learning is clearly seen to reduce the amount of communication between agents by up to 50%, while still maintaining cooperative behaviour. The agents are also demonstrated to learn to a large degree cooperative local behaviour from a central system

Exploring new territory: an initial investigation into the potential of a formal industry capacity building programme to shift values among Cape Town paratransit operators

Organisational Psychology’s focus on the formal business setting has resulted in the discipline limiting its potential contribution to and relevance in broader society. To address this shortfall this study was conducted in the paratransit industry, which is the largest contributor to the informal economy in South Africa. It is based on the argument that by applying discipline specific knowledge, Organisational Psychology may have the potential to assist in transforming the culture in the paratransit industry, a culture which has been described as violent, aggressive and undemocratic. As culture can shift through industry-leader driven changes in values, the first step was to understand what values are held by leaders within the paratransit industry. The second step was to find ways in which to shift values. Using Schwartz’s (1992) Theory of Basic Human Values as theoretical framework, this dissertation consequently served to surface the values among paratransit operators which may underlie the violent and aggressive culture in the Cape Town paratransit industry. Secondly, it sought to determine if value shifts may be achieved through formal business skills capacity training. To this end, the extent to which paratransit operators who had participated in such a training programme demonstrated different values to non-participant paratransit operators was assessed. By employing a quasi-experimental post-test design participants (n = 46) and non-participants (n = 46) in a particular three-year capacity-building programme responded to Schwartz et al.’s (2001) Portrait Values Questionnaire (PVQ), which assesses the universal value dimensions stipulated by Schwartz (1992), as well as to additional scales assessing trust in the City of Cape Town (CoCT) and Transport for Cape Town (TCT). The sample valued universalism, benevolence, conformity and security – values that are not generally associated with violent, aggressive and undemocratic behaviour. Power, on the other hand, was neither valued nor not valued although it had been expected to be espoused strongly. The only result in line with expectations was that participants valued stimulation to some extent. Participants indicated trust in the CoCT and TCT. While training participants and non-participant paratransit operators did not differ significantly in the degree to which they espoused the different values and their degree of trust in the two transport authorities, the effect sizes for the differences in conformity, power, security, and universalism as well as trust in the two transport authorities were meaningful. It needs to be noted, though, that a number of limitations in the study design, particularly that no pre-intervention data was available, means that it is not possible to assess if the values of paratransit operators had shifted over the duration of the programme. Consequently, one cannot be certain that such a programme is an effective means of shifting espoused values. If, however, the values espoused by participants in this study are a reflection of reality, then paratransit operators endorse values that lend themselves to the formation of a non-aggressive and democratic culture. Organisational psychologists can assist in bringing about a positive shift to the operating culture of the paratransit industry by translating these value-conform behaviours shown towards drivers and by encouraging similar behaviour in their work and over time, these minibus-taxi drivers may shift their values and behaviours in turn. From a theoretical perspective, the findings on the dimensionality of the PVQ in the sample suggest that even though Schwartz (1992) assumed the value dimensions in the Theory of Human Values to be universal, what indicates each of these value dimensions is context dependent. This calls into question the universal applicability of the PVQ as a measurement tool for these values. The relative endorsement of value dimensions in relation to each other, however, was found to be in line with Schwartz’s (1992) assumptions

Investigating the relationship between corporate tax avoidance and corporate culture in large South African companies

Not all companies are equally aggressive in their pursuit of corporate tax avoidance, which explains intensive research on the determinants of tax avoidance. Many determinants have been investigated, but the process of tax avoidance, and the relationships between corporate tax avoidance, longtermism (indicative of a stakeholder-orientated corporate culture), and CEO characteristics (informed by upper-echelon theory), are not yet fully understood. Much of previous research is conceptualised from theories such as principal-agent theory. This study investigates the influence of stakeholder orientation, using corporate culture, on corporate tax avoidance, in response to calls for more research using stakeholder theory. A mixed-method approach is used. The quantitative stream uses regressions to investigate the relationship between corporate tax avoidance, corporate culture, and tax-knowledgeable CEOs, based on a sample of 112 large, listed South African companies, studied over a period of 15 years. The South African setting allows the operationalisation of a tax-knowledgeable CEO, based the homogenous nature of CEOs' qualifications in South Africa, where many are chartered accountants. The results suggest that long-term oriented companies pay more tax on average. The results further suggest that tax knowledgeable CEOs are associated with more tax avoidance. The qualitative stream conducts eleven interviews with corporate tax advisors, showing the influence of corporate culture and CEO characteristics on corporate tax avoidance processes, but also how corporate culture and CEO-characteristics mutually inform each other. Altogether, the evidence indicates that the effect of corporate culture is less static than expected, and that the influence of corporate culture on tax avoidance can transcend the influence of CEO-characteristics, as an upperechelon effect. The interviews suggest mechanisms used by CEOs to influence tax culture, such as the creation of a company-wide awareness of the strategic importance of low effective tax rates. These results also indicate the ethical dilemma faced by executives of large companies when considering the use of tax-deductible corporate social responsibility initiatives, not to benefit shareholders or agents, but rather to benefit society as a corporate stakeholder, when governments would not

The economic impact of the Troubled Assets Relief Programme (TARP) in the USA: an assessment of the level to which an optimal allocation of funds occurred

The 2009 international fi nancial crisis has led to many countries,including the USA, bailing out their fi nancial institutions. Thisarticle provides a unique perspective of the bailout issue by lookingat the impact of the quantitative easing in monetary policy oncompetitiveness as well as providing multiplier impacts through theuse of the US 2002 I-O table. Specifi cally, three areas are consideredwithin this model: whether the Troubled Assets Relief Programme(TARP)1 bailout will give rise to greater economic effi ciencies andproductivity, which would include determining whether the TARPbailouts give rise to the survival of fi nancial institutions and thestabilisation of the fi nancial sector; determining the direct, indirectand induced impacts of the TARP bailout on the economy (shortterm);and determining the long-term benefi ts of the TARP 1 bailouton the economy (by focusing on long-term capital realisation). Thefi ndings of this econometric analysis raise questions of the validityof government intervention in the form of bailouts