North-West University
  • North-West, South Africa
Recent publications
David Lurie, the protagonist in Disgrace, boldly rejects the cyclical and persistent nature of state intrusion into private lives in post-apartheid South Africa. He presents a defence to counter a university academic committee’s public interrogation into what he perceives ought to be a private matter, a spectacle of his sexual exploitation of Soraya and Melanie Isaacs. He scoffs at the menace of disciplinary hearings such as the Truth and Reconciliation Commission, trivialises the opportunity to defend himself, and flouts the committee’s request, musing that in the new black politics his private life is public business. His obduracy to adapt to new political power and lesbian realities exhibits a false sense of entitlement to apartheid privileges. By analogy, Coetzee’s depiction of the plaas and the raped lesbian body of Lucy similarly indicts an evolving post-apartheid South Africa that wrestles with the racialised history and memory of political change. Disgrace taps into the deep psychological attributes of complex and menacing human relationships and the intersectionality of land redistribution, retribution, state-sponsored and private in/justice. I contend, ultimately, that testimony as memory, truth-telling as menace and apology as spectacle are disrupted in a problematic if disorienting archive of narrative in post-apartheid Southern African literature.
Disasters occur when hazards meet vulnerability. We must acknowledge the human-made components of both vulnerability and hazard and emphasize human agency in order to proactively reduce disaster impacts.
Behavioural toxicology is an emerging field of ecotoxicology gaining prominence in both aquatic and terrestrial environments. The aim of this work is to review studies investigating the avoidance behaviour of soil invertebrates in contaminated soils. The review begins with an overview of experimental design and abiotic factors that influence soil invertebrates’ behaviour followed by trends in literature related to three contaminant classes (metals, pesticides and organics). Despite the incidence of non-avoidance or even attraction in a few cases, a common theme across all contaminants reviewed is that avoidance test appears to be the most sensitive test in a suite of tests and species-specific responses. These findings reinforce the importance of testing avoidance behaviour on a battery of test organisms. The review concludes with a synthesis of current challenges is discussed with recommendations for future directions to fill data gaps identified.
The electronic structure and optical properties of a ternary thiostannate compound (α-Ba2SnS4) have been successfully predicted via ab initio calculations. Optimized structure was confirmed by both Bond Valence Sum (BVS) and charge distribution (CHARDI) validation models, which showed a reduction in the coordination number of the barium atom after structure optimization. The band structure confirmed that the α-Ba2SnS4 is a semiconductor material with a direct band gap, and the calculated band gap energy was 2.469 eV which was in good agreement with other literature reports. Calculated optical spectra (dielectric function, refractive index, reflectivity, absorption, energy loss function) of the compound exhibited a significant optical anisotropy. A plot of the dielectric function showed four transition frequencies, while the determinate frequencies values were consistent with the density of states. A high absorptivity of the electromagnetic waves in both visible and near UV regions was observed in the absorption spectra, which indicated the possible application of this compound in optoelectronic field as photocatalysts. The mechanical stability of this compound has been verified by the phonon calculation.
The tourism sector has always been a target of criticism due to the adverse environmental effects of travel and activities at tourist destinations. It is thus imperative for researchers and managers to seek tourism solutions that make business sense without raising sustainability-related issues. Particularly in the aftermath of the COVID-19 pandemic, virtual reality tourism (VRT), a form of digitally-driven albeit unconventional ex-situ touristic travel, has attracted the attention of multiple stakeholders in the sector. However, consumers’ perceptions of and motivations to use VRT as a sustainable solution for touristic activities are yet not fully understood. We address this deficiency in the literature by drawing upon expectancy theory to propose goal difficulty and reduction in the environmental impact of tourism (REI) as expectancy-related motivations, accomplishment as an instrumentality-related motivation and willingness to sacrifice as a valence-related motivation; we anticipate these motivations, in turn, to drive two outcomes: low- and high-effort pro-environmental behaviours. Analysing data collected from 350 individuals residing in the United States, we found support for all positive associations except for that of goal difficulty with high-effort pro-environmental behaviours and REI with both pro-environmental behaviours. We also tested and confirmed the moderating effects of the number of children in a household and daily green behaviours on some of the proposed associations. Our findings offer useful insights for future research and practice in the area.
Periods of economic recession are typically accompanied by the use of cost-cutting actions, such as wage cuts or freezes, increased workloads and reduced training expenditures. While such actions are expected to boost performance, at least in the short-term, their effects on employee attitudes and behaviours at work have been the subject of much research. In this study, we examine how management's use of cost-cutting actions could have a detrimental impact on two aspects of the employment relations climate—the quality of employee–management relations and the level of employees’ trust in management; further, we investigate how these relationships might lead to an increase in employee complaints against their organisations. Using multilevel data from 21,981 employees in 1,923 workplaces, we show that the use of cost-cutting actions violates the psychological contract, which, in turn, contributes to strained relations between employees and management. However, in workplaces where employees are actively involved in decision-making, cost-cutting actions are less likely to have a negative impact. We discuss the theoretical and practical implications of our study using psychological contract theory.
The principal aim of environmental impact assessment (EIA) is to foster sustainable development. Sustainability can be conceived along a ‘weak’ and ‘strong’ continuum, in which the latter holds that substitution of natural capital is severely limited, and evidence suggests that weak sustainability prevails in decision-making supported by EIA. Therefore, based on the assumption that strong sustainability is the required goal to protect biodiversity and mitigate future climate change, the aim of this paper is to establish the concept of transformative effectiveness to better evaluate how EIA can foster the transformation of stakeholders’ frames of references towards strong sustainability. The EIA systems of the US, EU, and Brazil were analyzed to identify the implicit and explicit drivers towards transformative change to a strong sustainability goal. A literature review of transformative change within impact assessment was used for identifying the necessary changes that need to come from both within policy actor networks and from the wider social-ecological-technological system in which EIA operates. From this, a new dimension of transactive effectiveness is characterized that can help to evaluate the extent to which EIA practice is transforming towards strong sustainability as a goal.
For every ton of palm oil produced, approximately 0.2 tons of palm decanter cake (PDC) waste is generated. Hence, there is a huge opportunity to valorize this organic waste, i.e., via the deployment of black soldier fly larvae (BSFL), which has been widely employed to convert various organic wastes into larval proteins and lipids. However, the PDC is mainly made up of lignocellulosic materials that are hard to digest by the BSFL. Therefore, this work attempted to grow BSFL in cellulase-pretreated PDC; thereby, providing an alternative solution to manage PDC waste. Results had shown that the cellulase pretreatment was effective in breaking down cellulose into glucose molecules, especially with higher cellulase dosage and longer treatment duration of up until 48 h. Subsequently, the maximum BSFL growth was found at 6.56 ± 2.69 mg/larva when being fed with PDC pre-treated by 1.0 wt% of cellulase for 72 h; which was about 4 mg higher than the controlled larva. Using a similar substrate, the highest protein yield and lipid yield from BSFL were attained at 1.63 ± 0.11 mg/larva (22.4 wt%) and 5.12 ± 1.01 mg/larva (69.9 wt%), respectively. In terms of biodiesel quality, a huge presence of saturated fatty acids had made the BSFL-based biodiesel oxidatively stable.
We develop two new classes of tests for the Weibull distribution based on Stein’s method. The proposed tests are applied in the full sample case as well as in the presence of random right censoring. We investigate the finite sample performance of the new tests using a comprehensive Monte Carlo study. In both the absence and presence of censoring, it is found that the newly proposed classes of tests outperform competing tests against the majority of the distributions considered. In the cases where censoring is present we consider various censoring distributions. Some remarks on the asymptotic properties of the proposed tests are included. We present another result of independent interest; a test initially proposed for use with full samples is amended to allow for testing for the Weibull distribution in the presence of censoring. The techniques developed in the paper are illustrated using two practical examples.
We analyze whether preferential trade agreements (PTAs) affect the incidence and pattern of antidumping (AD) filings. We find PTA membership results in a 29 percent (15 percent) decrease in the incidence of intra-PTA AD actions (measures). We then exploit variation in the content of PTAs and find the reduction is due to PTAs with explicit AD rules. We find that intra-PTA AD filings (measures) decrease by about 46 percent (34 percent) for PTAs with explicit AD rules. Our results are robust to controlling for other PTA-related phenomena, the emergence of China as the largest target of AD actions, and the role played by EU and US PTAs. Our findings highlight the effectiveness of PTA AD rules in curbing AD disputes among members. (121 words)
Scholars and industry stakeholders have exhibited an interest in identifying the underlying dimensions of viral memes. However, the recipe for creating a viral meme remains obscure. This study makes a phenomenological contribution by examining viral memes, exploring the antecedents (i.e., content‐related factors, customer‐related factors, and media‐related factors), consequences, and moderating factors using a mixed‐method approach. The study presents a holistic framework for creating viral memes based on the viewpoints of customers and industry stakeholders. Four quantitative studies (i.e., a lab experiment, an online quasi‐experiment, an event study, and a brand recall study) validate the theoretical model identified in the qualitative study. The research points to the potential of viral memes in marketing communications to enhance brand recall and brand engagement. The study found that viral memes are topical and highly relatable and are thus well received by the target groups, which increases customer engagement and brand recall. The marketers can adopt the findings of this study to design content for memes that consumers find relevant, iconic, humorous, and spreadable. Furthermore, marketers can use customer‐related factors suggested in the theoretical framework for enhancing escapism, social gratification, and content gratification for their target customers which in turn shall organically increase their reach within their target segments and enhance brand performance in terms of brand recall and brand engagement.
This paper reports on the presence of three Mallomonas species (Phylum Ochrophyta) in the Vaal River, South Africa. Scanning electron microscope observations of entire cells with intact scales and bristles allowed accurate identifications of M. corymbosa, M. kenyana and M. portae-ferreae. Descriptions and dimensions of each of the three species are given, their geographical distribution is discussed and physico-chemistry of the water at the time of their finding is presented. M. corymbosa was recorded for the first time in Africa, expanding its known geographical distribution to an additional continent. The climatic preferences of the tropical and subtropical species, M. kenyana were extended to temperate regions in South Africa. These species were present under eutrophic to hypertrophic conditions, a water temperature of 25.4 °C, neutral to slightly alkaline water (pH 7.25) and a conductivity value of 440 mS/cm.
This conceptual study provides insight into the strategic behaviors of firms facing slow growth in times of economic stagnation. Recognizing the inevitability of periods of economic stagnation—with another downturn expected as early as 2022, we note that most industry classifications are considered mature and characterized by a few extremely large companies in each industry group. We introduce the Fortune 500 as an important cross-industry collective of these large firms and suggest that they now comprise an institutional field. This development explains their isomorphic behavior during the recession triggered by the financial crisis of 2008 as well as their subsequent motivation for change. Using the pertinent literature from institutional theory and organizational change, we posit that the appropriate firm-level response (strategic choice) during periods of slow growth is to maintain legitimacy and membership in the field by adopting a proactive approach that focuses on improving top-line growth. We synthesize frameworks found in the literature and provide a “menu” of five strategic options companies should consider to turn their firms around by redirecting growth from the short term to the long term. We discuss implications for boards and executives anticipating significant economic deceleration.
Social media celebrities (SMCs) and social media platforms (SMPs) have become indispensable in today's business and marketing settings. Drawing on the celebrity influence model (CIM), this study examines the impact of SMCs on their followers' purchase intention and the moderating influence of SMP usage on the relationships between (a) SMCs and their followers' purchase intention, (b) para-social relationships (PSR) and purchase intention, and (c) identification and purchase intention. We collected 665 valid responses via an online questionnaire in China and then employed partial least squares structural equation modelling (PLS-SEM) to examine the proposed relationships between the variables. The findings revealed that SMCs do not significantly influence their followers' purchase intention directly; however, they do exert such influence through PSR and identification. The results further indicated that SMP usage moderates the effect of PSR and identification on purchase intention. Our study offers both theoretical and managerial contributions. Theoretically, the incorporation of CIM into this study's model augments the PSR and identification literature in the context of SMCs. Again, the moderating effect of SMP usage that we reveal is novel in the social media literature. In practice, marketers in China should consider the credibility and rapport a particular social media celebrity has with his or her followers before contracting that particular celebrity to endorse their products.
Diabetic neuropathy is a risk factor for developing complications such as autonomic cardiovascular disease, osteoarthropathy, foot ulcers, and infections, which may be the direct cause of death. Even worse, patients plagued by this condition display painful neuropathic symptoms that are usually severe and frequently lead to depression, anxiety, and sleep disarrays, eventually leading to a poor quality of life. There is a general interest in evaluating the therapeutic properties of topical capsaicin cream as an effective agent for pain relief in these patients. As such, the current review makes use of major search engines like PubMed and Google Scholar, to bring an updated analysis of clinical studies reporting on the therapeutic effects of capsaicin in patients with painful diabetic neuropathy. In fact, most of the summarized literature indicates that topical capsaicin (0.075 %) cream, when applied to the painful areas for approximately 8 weeks, can reduce pain, which may lead to clinical improvements in walking, working, and sleeping in patients with painful diabetic neuropathy. The current review also discusses essential information on capsaicin, including its source, bioavailability profile, as well as treatment doses and duration, to highlight its therapeutic potential.
Asteroseismology has grown from its beginnings three decades ago to a mature field teeming with discoveries and applications. This phenomenal growth has been enabled by space photometry with precision 10–100 times better than ground-based observations, with nearly continuous light curves for durations of weeks to years, and by large-scale ground-based surveys spanning years designed to detect all time-variable phenomena. The new high-precision data are full of surprises, deepening our understanding of the physics of stars. ▪ This review explores asteroseismic developments from the past decade primarily as a result of light curves from the Kepler and Transiting Exoplanet Survey Satellite space missions for massive upper main sequence OBAF stars, pre-main-sequence stars, peculiar stars, classical pulsators, white dwarfs and subdwarfs, and tidally interacting close binaries. ▪ The space missions have increased the numbers of pulsators in many classes by an order of magnitude. ▪ Asteroseismology measures fundamental stellar parameters and stellar interior physics—mass, radius, age, metallicity, luminosity, distance, magnetic fields, interior rotation, angular momentum transfer, convective overshoot, core-burning stage—supporting disparate fields such as galactic archeology, exoplanet host stars, supernovae progenitors, gamma-ray and gravitational wave precursors, close binary star origins and evolution, and standard candles. ▪ Stars are the luminous tracers of the Universe. Asteroseismology significantly improves models of stellar structure and evolution on which all inference from stars depends. Expected final online publication date for the Annual Review of Astronomy Volume 60 is August 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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6,695 members
Peet J Jansen van Rensburg
  • Research focus area: Human Metabolomics
Olaf Pollmann
  • School of Environmental Sciences and Development
Zelda De Lange-Loots
  • Centre of Excellence for Nutrition
Jeanetta Du Plessis
  • Faculty of Health Sciences
Eno Ebenso
  • Chemistry Group (School of Mathematical and Physical Sciences) and Material Science Innovation and Modelling (MaSIM) Research Focus Area
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