Evaluation of a service-learning elective as an approach to enhancing the pharmacist's role in health promotion in South Africa
- Authors: Srinivas, Sunitha C , Wrench, Wendy W
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: vital:6443 , http://hdl.handle.net/10962/d1006630
- Description: Background. A service-learning (SL) elective offered to final-year pharmacy students was introduced in 2007. The elective demonstrated a holistic approach to creating opportunities for future pharmacists to understand the current needs and future challenges of the burden of disease in developing countries such as South Africa and to foresee their key roles in health promotion. Methods. The 2007 Sasol National Festival of Science and Technology (SciFest) was chosen as the ideal platform to implement this elective. Evaluation of the elective was carried out in association with the Academic Development Centre using a web-based software tool known as the ADC evaluation assistant (ADCEA). The ADCEA consisted of a ‘question bank’ from which the course facilitators selected nine ranked closed questions as well as two open-ended questions. Results. SciFest participation, in the course of the service-learning elective, was acknowledged by students to have prepared them as responsible citizens to undertake health promotion in the public sector healthcare system. Conclusion. Students’ experiences of the learning opportunities provided in the SciFest elective highlight the strengths of this SL programme.
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- Date Issued: 2012
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
An ion-imprinted polymer for the selective extraction of mercury(II) ions in aqueous media
- Authors: Batlokwa, Bareki Shima , Chimuka, Luke , Tshentu, Zenixole , Cukrowska, Ewa , Torto, Nelson
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6566 , http://hdl.handle.net/10962/d1004125
- Description: A double-imprinted polymer exhibiting high sensitivity for mercury(II) in aqueous solution is presented. Polymer particles imprinted with mercury(II) were synthesised by copolymerising the functional and cross-linking monomers, N’–[3– (Trimethoxysilyl)–propyl]diethylenetriamine (TPET) and tetraethylorthosilicate (TEOS). A double-imprinting procedure employing hexadecyltrimethylammonium bromide (CTAB), as a second template to improve the efficiency of the polymer, was adopted. The imprinted polymer was characterised by FTIR, scanning electron microscopy (SEM) and the average size determined by screen analysis using standard test sieves. Relative selective coefficients (k`) of the imprinted polymer evaluated from selective binding studies between Hg2+ and Cu2+ or Hg2+ and Cd2+ were 10 588 and 3 147, respectively. These values indicated highly-favoured Hg2+ extractions over the 2 competing ions. The results of spiked and real water samples showed high extraction efficiencies of Hg2+ ions, (over 84%) as evaluated from the detected unextracted Hg2+ ions by ICP-OES. The method exhibited a dynamic response concentration range for Hg2+ between 0.01 and 20 μg/mℓ, with a detection limit (LOD, 3σ) of 0.000036 μg/mℓ (36 ng/ℓ) that meets the monitoring requirements for the USA EPA of 2 000 ng/ℓ for Hg2+ in drinking water. Generally, the data (n=10) had percentage relative standard deviations (%RSD) of less than 4%. Satisfactory results were also obtained when the prepared sorbent was applied for the pre-concentration of Hg2+ from an aqueous certified reference material. These findings indicate that the double-imprinted polymer has potential to be used as an efficient extraction material for the selective pre–concentration of mercury(II) ions in aqueous environments.
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- Date Issued: 2012
Spatial variation in the macrobenthic assemblages of intertidal seagrass along the long axis of an estuary
- Authors: Barnes, R S K , Ellwood, M D F
- Date: 2014-05-29
- Language: English
- Type: Article
- Identifier: vital:6870 , http://hdl.handle.net/10962/d1011513
- Description: Invertebrate macrofaunal biodiversity within intertidal seagrass meadows was investigated over a salinity gradient of <5–35 in the Knysna estuarine system (Garden Route National Park, South Africa). Rather than the classic gradual decline in species richness with distance from the mouth there were zones of considerable faunal stability separated by relatively sharp discontinuities. At the point upstream at which salinity regularly falls below 30, the rich, diverse and highly spatially variable downstream faunal assemblage changed to a less rich, less diverse and more uniform one that dominated the upstream stretch without any further upstream reduction in richness. Nevertheless, without loss of overall richness, assemblage composition changed, again rapidly, in the upper region of the upstream stretch to a zone dominated by the microgastropod Hydrobia, which otherwise occurs in the Knysna system only in highly sheltered regions of the downstream stretch where it is also dominant. The upstream faunal assemblage was a subset of that in the marine-influenced downstream region not a different replacing one. Position along the estuarine gradient accounted for 29% of total assemblage variation. Overall faunal abundance declined with distance upstream until the Hydrobia zone where it rose sharply, but there was no evidence of increase in density of those species remaining on putative release from competition.
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M 87 at metre wavelengths: the LOFAR picture
- Authors: Smirnov, Oleg M , De Gasperin, F , Orrú, E , Murgia, M , Merloni, A , Falcke, H , Beck, R , Beswick, R , Bîrzan, L , Bonafede, A , Brüggen, M
- Date: 2012
- Subjects: radiation mechanisms: non-thermal, galaxies: active, galaxies: individual: M 87, galaxies: clusters: individual: Virgo, galaxies: jets, radio continuum: galaxies
- Language: English
- Type: Article
- Identifier: vital:6821 , http://hdl.handle.net/10962/d1004434
- Description: Context.M 87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4 × 109 M⊙, whose activity is responsible for the extended (80 kpc) radio lobes that surround the galaxy. The energy generated by matter falling onto the central black hole is ejected and transferred to the intra-cluster medium via a relativistic jet and morphologically complex systems of buoyant bubbles, which rise towards the edges of the extended halo. Aims. To place constraints on past activity cycles of the active nucleus, images of M 87 were produced at low radio frequencies never explored before at these high spatial resolution and dynamic range. To disentangle different synchrotron models and place constraints on source magnetic field, age and energetics, we also performed a detailed spectral analysis of M 87 extended radio-halo. Methods. We present the first observations made with the new Low-Frequency Array (LOFAR) of M 87 at frequencies down to 20 MHz. Three observations were conducted, at 15−30 MHz, 30−77 MHz and 116−162 MHz. We used these observations together with archival data to produce a low-frequency spectral index map and to perform a spectral analysis in the wide frequency range 30 MHz–10 GHz. Results. We do not find any sign of new extended emissions; on the contrary the source appears well confined by the high pressure of the intra-cluster medium. A continuous injection of relativistic electrons is the model that best fits our data, and provides a scenario in which the lobes are still supplied by fresh relativistic particles from the active galactic nuclei. We suggest that the discrepancy between the low-frequency radio-spectral slope in the core and in the halo implies a strong adiabatic expansion of the plasma as soon as it leaves the core area. The extended halo has an equipartition magnetic field strength of ≃10 μG, which increases to ≃13 μG in the zones where the particle flows are more active. The continuous injection model for synchrotron ageing provides an age for the halo of ≃40 Myr, which in turn provides a jet kinetic power of 6−10 × 1044 erg s-1.
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- Date Issued: 2012
Dynamics of a lattice Universe : the dust approximation in cosmology
- Authors: Bruneton, J-P , Larena, Julien
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6789 , http://hdl.handle.net/10962/d1006941
- Description: We find a solution to Einstein field equations for a regular toroidal lattice of size L with equal masses M at the centre of each cell; this solution is exact at order M/L. Such a solution is convenient to study the dynamics of an assembly of galaxy-like objects. We find that the solution is expanding (or contracting) in exactly the same way as the solution of a Friedman–Lemaître–Robertson–Walker Universe with dust having the same average density as our model. This points towards the absence of backreaction in a Universe filled with an infinite number of objects, and this validates the fluid approximation, as far as dynamics is concerned, and at the level of approximation considered in this work.
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- Date Issued: 2012
From the grave to the cradle : the possibility of post-mortem gamete retrieval and reproduction in South Africa
- Authors: Kruuse, Helen
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:24533 , http://hdl.handle.net/10962/36254 , http://www.tandfonline.com/doi/abs/10.1080/19962126.2012.11865059
- Description: The development of reproductive technologies in the last century, such as effective contraceptive methods, artificial insemination, pre-implantation genetic diagnosis, amongst others, has fundamentally reshaped traditional concepts of reproduction parenthood and has raised practical and ethical concerns. This article describes one such development, namely, post-mortem gamete retrieval (PMGR) for the purposes of posthumous reproduction. In exploring the particular concerns arising from this technology, I argue that South Africa lacks a coherent, considered approach to the issue. In considering models adopted in overseas jurisdictions, and the various bases for the legalisation of such a procedure, I adopt an interest theory of rights to argue for restricted access to such a technology in suitable circumstances.
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- Date Issued: 2012
Gravitational entropy and thermodynamics away from the horizon
- Authors: Brustein, R , Medved, A J M
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6818 , http://hdl.handle.net/10962/d1004328
- Description: We define, by an integral of geometric quantities over a spherical shell of arbitrary radius, an invariant gravitational entropy. This definition relies on defining a gravitational energy and pressure, and it reduces at the horizon of both black branes and black holes to Wald's Noether charge entropy. We support the thermodynamic interpretation of the proposed entropy by showing that, for some cases, the field theory duals of the entropy, energy and pressure are the same as the corresponding quantities in the field theory. In this context, the Einstein equations are equivalent to the field theory thermodynamic relation TdS=dE+PdV supplemented by an equation of state
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- Date Issued: 2012
Contrasting habitat associations of imperilled endemic stream fishes from a global biodiversity hot spot
- Authors: Chakona, Albert , Swartz, E R
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:7148 , http://hdl.handle.net/10962/d1011850 , http://www.biomedcentral.com/1472-6785/12/19
- Description: Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor.
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- Date Issued: 2012
Three tales of Theal: biography, history and ethnography on the Eastern Frontier
- Authors: Naidu, Samantha
- Date: 2012
- Language: English
- Type: Article , text
- Identifier: vital:24529 , http://hdl.handle.net/10962/36216 , https://www.jstor.org/stable/23267873?seq=1#page_scan_tab_contents , https://orcid.org/0000-0001-9456-8657
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- Date Issued: 2012
Treatment of post traumatic stress disorder following an armed robbery : a case study testing the transportability of trauma-focused cognitive-behavioural therapy to urban Africans
- Authors: Drake, B , Edwards, David J A
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6225 , http://hdl.handle.net/10962/d1007775
- Description: John, an urban African male who developed post traumatic stress disorder (PTSD) following an armed robbery at the petrol station where he worked, was treated with 12 sessions of Trauma-focused cognitive behaviour therapy. Intervention involved a combination of psycho-education, prolonged imaginal exposure, cognitive restructuring and behavioural assignments. This article is a systematic case study of his treatment which included a comprehensive narrative and tracking of progress by means of the Post traumatic Diagnostic Scale. John responded well to the treatment, finding it acceptable and credible and remained free of PTSD symptoms at 15 months follow up. It is argued, based on the principles of Elliott’s Hermeneutic Single Case Efficacy Design, that there is evidence from within the narrative that it was the treatment that led to remission of symptoms. This case study demonstrates the cognitive, emotional and behavioural processes underlying John’s PTSD, which fits with those extensively described in the research literature, and that this evidence-based treatment developed in a westernised context is transportable to work with urban Africans.
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- Date Issued: 2012
Contrasting habitat associations of imperilled endemic stream fishes from a global biodiversity hot spot
- Authors: Chakona, Albert , Swartz, E R
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6777 , http://hdl.handle.net/10962/d1008087
- Description: Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor.
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- Date Issued: 2012
Changing sediment yield and sediment dynamics in the Karoo uplands, South Africa : post-European impacts
- Authors: Foster, I D L , Rowntree, Kate M , Boardman, J , Mighall, T M
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6684 , http://hdl.handle.net/10962/d1006683
- Description: We provide an overview of published results and a significant body of new data from an ongoing research programme designed to reconstruct sediment yields and sources in small (<60 km2) catchments in the Eastern Cape, South Africa over the last 150 years. Our analysis of four catchments has determined that sediment yield increased significantly in the latter half of the 20th Century but that the exact timing of these increases was different in each of the four catchments. In two high altitude locations, sediment yield increases were not associated with a significant change in sediment source, although in one case areas of former cultivation appear to have made a slightly greater contribution since the 1960s. In a third catchment, increases in sediment yield appear to have been driven by the development of badlands and by an increase in connectivity between the badlands and the main channel network in the 1960s. In the fourth catchment, increased connectivity between the main catchment and dam occurred as a result of the construction of a causeway to carry a main road and by the construction of culverts beneath the road. Occasional changes in sediment source have also been identified in the sedimentary record but these were not linked directly to road construction. Research to date shows the complexity of sediment delivery in these semi-arid catchment systems and emphasises the need to combine sediment yield with source ascription in order to better understand the dynamics of these systems.
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- Date Issued: 2012
In vitro dissolution kinetics of Captopril from microspheres manufactured by solvent evaporation
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: vital:6390 , http://hdl.handle.net/10962/d1006311
- Description: The aim of this study was to develop and assess captopril-loaded microspheres in which Methocel and Eudragit RS were used as release-controlling factors and to evaluate captopril (CPT) release using kinetic models. Drug-excipient interactions were evaluated using infrared studies, and the physical appearance was characterized using scanning electron microscopy (SEM). A burst effect was observed during the first stage of dissolution for most batches of microspheres. SEM results reveal that this may be attributed to dissolution of captopril crystals that were present on the surface, embedded in the superficial layer of the matrix materials, trapped near the surface of the microspheres, or that may have diffused rapidly through the porous surface of the capsules. The release data generated during in vitro release studies were fitted to zero-order, first-order, Higuchi, Korsmeyer–Peppas, Kopcha, and Makoid–Banakar models. The release kinetics of captopril from most formulations followed a classical Fickian diffusion mechanism. SEM photographs showed that diffusion took place through pores located in the surface of the microcapsules. The Kopcha model diffusion and erosion terms showed a predominance of diffusion relative to swelling or erosion throughout the entire test period. The drug release mechanism was also confirmed by the Makoid–Banakar and Korsmeyer–Peppas model exponents. This further supports a diffusion–release mechanism for most formulations. The models postulate that the total drug released is a summation of several mechanisms (viz., burst release, relaxation-induced controlled release, and diffusional release). These results also support the potential application of Eudragit/Methocel microspheres as a suitable sustained-release drug delivery system for captopril.
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- Date Issued: 2012
Surface electrochemistry : structured electrode, synthesis, and characterization
- Authors: Bedioui, Fethi , Nyokong, Tebello , Zagal, Jose H
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6567 , http://hdl.handle.net/10962/d1004126 , http://dx.doi.org/10.1155/2012/405825
- Description: From introduction: The aim of this special issue is to show, through recent updated significant examples, how the electrochemical techniques allow the unique characterization of specific properties of micro- and nanostructured materials that offer varied possibilities of uses and the preparation of specific types of ordered materials that take advantage of electrochemical synthetic methods such as structuring nanosized wires and dots, to cite only two examples.
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- Date Issued: 2012
Graviton n-point functions for UV-complete theories in Anti-de Sitter space
- Authors: Brustein, R , Medved, A J M
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: vital:6820 , http://hdl.handle.net/10962/d1004427
- Description: We calculate graviton n-point functions in an anti-de Sitter black brane background for effective gravity theories whose linearized equations of motion have at most two time derivatives. We compare the n-point functions in Einstein gravity to those in theories whose leading correction is quadratic in the Riemann tensor. The comparison is made for any number of gravitons and for all physical graviton modes in a kinematic region for which the leading correction can significantly modify the Einstein result. We find that the n-point functions of Einstein gravity depend on at most a single angle, whereas those of the corrected theories may depend on two angles. For the four-point functions, Einstein gravity exhibits linear dependence on the Mandelstam variable s versus a quadratic dependence on s for the corrected theory.
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- Date Issued: 2012
The use of response surface methodology to evaluate the impact of level 2 SUPAC–IR changes on the in vitro release of metronidazole and ranitidine from a fixed-dose combination tablet
- Authors: King’ori, Loti D , Walker, Roderick B
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: vital:6391 , http://hdl.handle.net/10962/d1006313
- Description: The purpose of this study was to evaluate the effect of different levels of disintegrant (croscarmellose sodium, CCS), binder (polyvinylprrolidone K30, PVP–K30), and lubricant (magnesium stearate) on the in vitro release of metronidazole (MTZ) and rantidine (RTD) from a solid oral fixed-dose combination tablet. The excipient levels investigated were Level 2 changes in component and composition described in the Scale-Up and Post Approval Changes for Immediate Release (SUPAC–IR) guidance (1). Batches of tablets (1000 units) were manufactured by wet granulation using a Saral high-shear mixer granulator and a Manesty B3B rotary tablet press. Weight uniformity, friability, and disintegration of all tablets were assessed, and all batches complied with compendial specifications. The amount of drug released (Q) at ten minutes was dependent on the levels of CCS in the formulation, and the effect of PVP–K30 and magnesium stearate was dependent on the levels of CCS. Synergistic interactions between independent variables were observed for the Q10 value for RTD, whereas PVP–K30 and magnesium stearate exhibited an antagonistic effect on the Q10 values for MTZ and RTD. The use of response surface methodology facilitated an investigation into the effect of Level 2 component and composition changes, as described in SUPAC–IR, on the in vitro release of MTZ and RTD from a fixed-dose combination (FDC) solid oral dosage form (SODF).
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- Date Issued: 2012
Cryptic variation in an ecological indicator organism: mitochondrial and nuclear DNA sequence data confirm distinct lineages of Baetis harrisoni Barnard (Ephemeroptera: Baetidae) in Southern Africa
- Authors: Pereira-da-Conceicoa, Lyndall L , Price, Benjamin W , Barber-James, Helen M , Barker, Nigel P , De Moor, Ferdy C , Villet, Martin H
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6535 , http://hdl.handle.net/10962/d1005976 , https://dx.doi.org/10.1186/1471-2148-12-26
- Description: Baetis harrisoni Barnard is a mayfly frequently encountered in river studies across Africa, but the external morphological features used for identifying nymphs have been observed to vary subtly between different geographic locations. It has been associated with a wide range of ecological conditions, including pH extremes of pH 2.9–10.0 in polluted waters. We present a molecular study of the genetic variation within B. harrisoni across 21 rivers in its distribution range in southern Africa.
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- Date Issued: 2012
Treating complex post-traumatic stress disorder following childhood neglect, sexual abuse and revictimisation : interpretative reflections on the case of Khuselwa
- Authors: Padmanabhanunni, A , Edwards, David J A
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6233 , http://hdl.handle.net/10962/d1007783
- Description: This paper describes the psychological assessment and treatment process with Khuselwa, a South African adolescent survivor of multiple sexual traumas presenting with complex post-traumatic stress disorder (PTSD). The paper identifies some of the common barriers encountered by practitioners in delivering treatments in local contexts and highlights the role of external safety and stability and social support in providing a vehicle for change and a basis for overcoming the psychological handicaps reinforced by repeated and multiple traumas and chronic neglect.
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- Date Issued: 2012
Anatomy of a pottery bonfiring in the Port St Johns region, Eastern Cape, South Africa
- Authors: Steele, John
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/1034 , vital:30232
- Description: This paper seeks to document and contextualise the unique bonfiring methods of octogenarian potter Alice Gqa Nongebeza, who works from her homestead at Nkonxeni village in the Tombo area near Port St Johns. Her firing technique is compared with those of fellow local potters Debora Nomathamsanqa Ntloya and Nontwazana Dunjana. These three Mpondo potters, and their understudies, create ceramic utilityware and other items for a mainly local market that sometimes also appeals to collectors and tourists. Although they are aware of each other, they use their own clay sources and clayworking methods, and have evolved very different firing techniques. This paper, with reference also to potters in KwaZulu-Natal, shows that Nongebeza, in particular, has developed a rare approach to firing, and calls for the inclusion of her type of firing technique in African firing lexicons. It also calls for greater attention to sequential firing detail as practised by individual potters, in forthcoming reports that add to knowledge about zeroelectricity- usage ceramics production in southern Africa, and elsewhere.
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- Date Issued: 2012