Status of tailings dumps : let D5s go working in the past?

It was decided in the De Beers v Ataqua Mining (Pty) Ltd that \u27\u27tailings dumps\u27\u27 created by mining companies before the Mineral and Petroleum Resources Development Act, 28 of 2002 (&quot;the MPRDA&quot;) came into operation are not governed by its provisions because such dumps are not &quot;residue stockpiles&quot; or &quot;residue deposits&quot; for purposes of the MPRDA. Ownership of tailings dumps is determined by the common law principles of accession. Ownership of a movable dump has to be transferred by one of the recognised forms of delivery of movables. Processing of these dumps will, however, still be subject to compliance with South African environmental, health and safety laws in general. It is submitted that mine dumps or tailings dumps created upon the exercise of &quot;old order mining rights&quot; before the commencement of the MPRDA and even after commencement of the MPRDA until eventual termination of the &quot;old order mining rights&quot; are not subject to the extensive, mining, environmental, empowerment provisions of the MPRDA. Termination of &quot;old order mining rights&quot; takes place upon: (i) refusal of an application for conversion of a mining right during (or even after) the period of transition, (ii) conversion into and registration of new order mining rights during (or even after) the period of transition or (iii) termination of unconverted &quot;old order mining rights&quot; on 30 April 2009. To the extent that this decision has made it possible to embark on a shorter and less cumbersome route in the reprocessing and eventual disappearance of most tailings dumps, it is to be welcomed from an economical, environmental, job creation and aesthetic perspective. Proposed amendments to the MPRDA to undo the impact of the De Beers decision should be carefully considered against these mentioned benefits and a possible finding that it may amount to an expropriation without compensation. <br /

The impact of an electricity generation tax on the South African economy

In the 2008 budget of the Minister of Finance, the South African Government proposed to impose a 2 cents/kilowatt-hour (c/kWh) tax on the sale of electricity generated from non-renewable sources; this tax is to be collected at source by the producers/generators of electricity. The intention of this measure is to serve a dual purpose of protecting the environment and helping to manage the current electricity supply shortages by reducing demand. The objective here is to evaluate the impact of such an electricity generation tax on the South African, SACU and SADC economies. The paper firstly considers the theoretical foundations of an electricity generation tax supported by international experiences in this regard. This section also contrasts the suitability of a permit with a tax system to achieve CO2 emission reduction. We subsequently apply the Global Trade Analysis Project (GTAP) model to evaluate the impact of an electricity generation tax on the South African, SACU and SADC economies. We simulate the proposed tax as a 10 percent increase in the output price of electricity. We assume a closure rule that allows unskilled labour to migrate and a limited skilled workforce. As expected, the electricity generation tax will reduce demand. Due to the decrease in domestic demand, export volume increases and import volume decreases, this is despite a weaker terms of trade. We also found that unemployment for unskilled labour increases and wages of skilled workers are expected to decrease. A unilateral electricity generation tax will benefit other SACU and SADC countries through an improvement in relative competitiveness, as shown by the improvement of the terms of trade for these regions. If, however, the benefits of pollution abatement are internalised, then electricity generation tax is expected to yield a positive effect on the South African economy.

AE Aquarii: A Short Review

The nova-like variable AE Aquarii has been continuously studied since its discovery on photographic plates in 1934. In this short review the peculiar multi-wavelength properties of AE Aquarii will be reviewed and explained in context of its evolution from a high mass transfer phase, during which period it could have been a supersoft X-ray source (SSS)

Strong plasmonic fluorescence enhancement of individual plant light-harvesting complexes

Plasmonic coupling of metallic nanoparticles and adjacent pigments can dramatically increase the brightness of the pigments due to the enhanced local electric field. Here, we demonstrate that the fluorescence brightness of a single plant light-harvesting complex (LHCII) can be significantly enhanced when coupled to single gold nanorods (AuNRs). The AuNRs utilized in this study were prepared via chemical reactions, and the hybrid system was constructed using a simple and economical spin-assisted layer-by-layer technique. Enhancement of fluorescence brightness of up to 240-fold was observed, accompanied by a 109-fold decrease in the average (amplitude-weighted) fluorescence lifetime from approximately 3.5 ns down to 32 ps, corresponding to an excitation enhancement of 63-fold and emission enhancement of up to 3.8-fold. This large enhancement is due to the strong spectral overlap of the longitudinal localized surface plasmon resonance of the utilized AuNRs and the absorption or emission bands of LHCII. This study provides an inexpensive strategy to explore the fluorescence dynamics of weakly emitting photosynthetic light-harvesting complexes at the single molecule level.Comment: 23 pages, 6 figures, 2 supplementary figures, and supplementary equation

The Impact of Surface Coal Mining on the Pre- and Post-Mining Agricultural Potential of the Grassland Biome of Southern Africa

Surface mining of coal is widespread in the grassland areas of the Mpumalanga Province in South Africa, and is the main cause of many environmental impacts in this agriculturally important region. To ensure healthy and productive vegetation after the reclamation process, disturbed soils need to be ameliorated and re-vegetated with locally adapted grass species to protect, preserve and improve soils for future agricultural use. To date, soil compaction is regarded as one of the main factors that cause severe restrictions in the effective rooting depth of plants, and the level of compaction is strongly influenced by altered soil water contents, soil texture, soil structure and often non-existing organic matter contents. Imported organic materials and enhanced plant root development may lead to reduced effects of soil compaction and an increased amount of moisture in the soil profile, which becomes available for plant growth during the growing season. This research focussed on the various amelioration aspects to alleviate and mitigate soil compaction to promote sustainable vegetation establishment and production to reinstate the agricultural potential of the disturbed environment. With associated soil amelioration, an increase in biomass production, of selected plant species was noted to be 52% higher on soil that was amended with 40 t/ha of organic amendment, in comparison to the soil that did not receive any. The correct selection of species with a known root structure and basic management requirement has, therefore, the potential to be useful in creating an organically rich, alleviated and more sustainable soil environment to ensure improved rehabilitation results of surface coal mines. It can be concluded, that sufficient data has shown that reclaimed surface coal mine soils can serve as a valuable resource to the animal production industry as well as to local communities, if managed correctly

Detection of human papillomavirus DNA with in situ hybridisation in oral squamous carcinoma in a rural black population

No Abstract

Aspects of rabies epidemiology in Tsumkwe District, Namibia

Aspects of rabies epidemiology were investigated in the Tsumkwe District, Namibia, during December 1993 and January 1994. A cross-sectional seroepidemiological survey for rabies antibodies was carried out in domestic (n = 70) and wild dogs [Lycaon pictus (n = 6)]. An overall seroprevalence rate of 30 % was found in domestic dogs, but it must be borne in mind that seroconversion can result from infections from either rabies or rabies-related viruses. Older dogs were more likely to be seropositive and there was spatial and temporal clustering of seropositivity. No wild dogs were found seropositive. A demographic survey of the domestic-dog population in the area showed that the total dog-population size was 132, or 0,027 dogs per square km . The dog population consisted mainly of young dogs with a median age of 1 ,5 years, and had a female bias of 0,63 males per female. Questionnaire surveys suggested that spotted hyaenas (Crocuta crocuta) and black-backed jackals (Canis mesomelas) were the most common larger carnivores found in and around villages, and that dogs were kept mainly for guarding.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.British Ecological Society, with indirect help from Grand Canyon Spur, Windhoek. Ministry of Environment and Tourism. WWF (US)

Seroepidemiological survey of sympatric domestic and wild dogs (Lycaon pictus) in Tsumkwe District, north-eastern Namibia

Disease is a potential threat to many endangered populations and may originate from sympatric domestic species. This paper describes a cross-sectional serological survey of canine pathogens carried out in domestic (n = 70) and wild dogs (Lycaon pictus) (n = 6), in Tsumkwe District, northeastern Namibia. Evidence of past exposure to canine distemper virus, canine adenovirus and parainfluenza virus was evident in both wild and domestic dogs with this, the first, documented exposure of free-living wild dogs to canine distemper. Domestic dogs were also exposed to rabies virus, canine parvovirus and coronavirus. There was no pathogen to which wild dogs, but not domestic dogs, were exposed. With wild dogs known to be susceptible to rabies and canine distemper, these may be the greatest threat to this population of wild dogs, although some wild dogs can clearly survive infection with canine distemper.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.British Ecological Society. Grand Canyon Spur, Windhoek. Ministry of Environment and Tourism. WWF (US)

Biological modelling of the radiation dose escalation effect of regional hyperthermia in cervical cancer

Background Locoregional hyperthermia combined with radiotherapy significantly improves locoregional control and overall survival for cervical tumors compared to radiotherapy alone. In this study biological modelling is applied to quantify the effect of radiosensitization for three cervical cancer patients to evaluate the improvement in equivalent dose for the combination treatment with radiotherapy and hyperthermia. Methods The Linear-Quadratic (LQ) model extended with temperature-dependent LQ-parameters α and β was used to model radiosensitization by hyperthermia and to calculate the conventional radiation dose that is equivalent in biological effect to the combined radiotherapy and hyperthermia treatment. External beam radiotherapy planning was performed based on a prescription dose of 46Gy in 23 fractions of 2Gy. Hyperthermia treatment using the AMC-4 system was simulated based on the actual optimized system settings used during treatment. Results The simulated hyperthermia treatments for the 3 patients yielded a T50 of 40.1 °C, 40.5 °C, 41.1 °C and a T90 of 39.2 °C, 39.7 °C, 40.4 °C, respectively. The combined radiotherapy and hyperthermia treatment resulted in a D95 of 52.5Gy, 55.5Gy, 56.9Gy in the GTV, a dose escalation of 7.3–11.9Gy compared to radiotherapy alone (D95 = 45.0–45.5Gy). Conclusions This study applied biological modelling to evaluate radiosensitization by hyperthermia as a radiation-dose escalation for cervical cancer patients. This model is very useful to compare the effectiveness of different treatment schedules for combined radiotherapy and hyperthermia treatments and to guide the design of clinical studies on dose escalation using hyperthermia in a multi-modality setting