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PurposeMethodsResultsConclusionAlthough fragility hip fractures (HF) in the South African (SA) population are among the lowest worldwide, the incidence of HF is expected to more than double over the next few decades. Little is known about the contributors to increased hip fracture risk, including low bone mineral density (BMD), in our unique population. In addition, the ability of the recently calibrated SA Fracture Risk Assessment Tool (FRAX) to identify high fracture risk in the SA population accurately has not been validated.A retrospective, descriptive, cohort study of SA postmenopausal women and men ≥ 50 years who presented with fragility HFs was conducted. The ability of clinical risk factors (CRFs) and BMD measured by dual-energy X-ray absorptiometry (DXA), as well as calculated FRAX probability scores, to identify the known high fracture risk in SA patients were evaluated. The SA FRAX tool was used, and a high fracture risk defined if the United States (US) fixed thresholds for major osteoporotic (MOF) and/or HF risk were exceeded (≥ 20% and ≥ 3% over 10 years respectively).A total of 163 patients were included. The most useful predictive CRFs were age and gender, recreational toxins in men, and a history of falls. Most were females (71%), who were older than males. DXA-BMD and FRAX-HF calculations best identified the known high fracture risk in the study cohort. FRAX-MOF calculations performed poorly.Fracture risk assessment tools did not identify the known high fracture risk in all of the elderly study cohort with HF. Clinicians must continue to appreciate the important role of a good clinical assessment to ensure optimal fracture risk prediction. [ABSTRACT FROM AUTHOR]

The structural and environmental heterogeneity within southern Africa has given rise to many morphological forms of Psammophylax rhombeatus distributed throughout the country, with previous studies neglecting the associated molecular significance of these forms. The species’ widespread, generalist ecology coupled with the substantial phylogenetic structuring previously acknowledged within the species, makes P. rhombeatus the ideal candidate for phylogeographic analyses. Using 103 samples, representing the full distribution of the species, phylogenetic analyses retrieved four well-supported clades: south-eastern South Africa, south-western South Africa, north-eastern South Africa and western South Africa. Although not variable enough to warrant taxonomic re-evaluation, the clades are phylogenetically distinguishable, with relatively high intraspecific genetic divergence values separating them, irrespective of the small geographic distances separating populations. This is likely a product of the taxon’s habitat-generalist lifestyle, enabling them to bypass vicariant barriers that might otherwise cause speciation in less versatile species. The clades are also geographically distinct, with little overlap, indicating previous vicariance, a finding that is supported by the split of P. rhombeatus from P. ocellatus in the mid-Pliocene, followed by the diversification of P. rhombeatus into four clades throughout the Pleistocene. The genetic structuring observed in P. rhombeatus may be a product of population expansion following ancient refugial isolation (potentially Last Glacial Maximum). The morphological groupings highlighted in previous studies are loosely attributable to the molecular clades identified in the phylogenetic reconstruction, highlighting the complex interplay of genetic and morphological characteristics in the process of speciation, and their representation in systematic accounts. [ABSTRACT FROM AUTHOR]

Malignant myopericytoma is an exceedingly rare soft tissue tumour with only 14 documented cases in the scientific literature. Myopericytomas can occur in association with HIV-AIDS and have a predilection for internal organs such as the bronchus, larynx, liver and brain. Ebstein-Barr virus encoded small RNA(EBER) was positive in three out of 14 cases. In this case report we present the second documented case of a malignant myopericytoma, with a positive EBER found intracranially – specifically in the supratentorial compartment – invading the superior sagittal sinus. Gross total excision of the tumour was achieved, and the patient responded well with no recurrence with only highly active antiretroviral therapy (HAART). No chemotherapy or radiotherapy has been necessary. [ABSTRACT FROM AUTHOR]

Graph-based frames have been introduced as a logical framework which internalises an inherent boundary to knowability (referred to as 'informational entropy'), due, e.g. to perceptual, evidential or linguistic limits. They also support the interpretation of lattice-based (modal) logics as hyper-constructive logics of evidential reasoning. Conceptually, the present paper proposes graph-based frames as a formal framework suitable for generalising Pawlak's rough set theory to a setting in which inherent limits to knowability exist and need to be considered. Technically, the present paper establishes systematic connections between the first-order correspondents of Sahlqvist modal reduction principles on Kripke frames, and on the more general relational environments of graph-based and polarity-based frames. This work is part of a research line aiming at: (a) comparing and inter-relating the various (first-order) conditions corresponding to a given (modal) axiom in different relational semantics; (b) recognising when first-order sentences in the frame-correspondence languages of different relational structures encode the same 'modal content'; (c) meaningfully transferring relational properties across different semantic contexts. The present paper develops these results for the graph-based semantics, polarity-based semantics, and all Sahlqvist modal reduction principles. As an application, we study well known modal axioms in rough set theory (such as those corresponding to seriality, reflexivity, and transitivity) on graph-based frames and show that, although these axioms correspond to different first-order conditions on graph-based frames, their intuitive meaning is retained. This allows us to introduce the notion of hyperconstructivist approximation spaces as the subclass of graph-based frames defined by the first-order conditions corresponding to the same modal axioms defining classical generalised approximation spaces, and to transfer the properties and the intuitive understanding of different approximation spaces to the more general framework of graph-based frames. The approach presented in this paper provides a base for systematically comparing and connecting various formal frameworks in rough set theory, and for the transfer of insights across different frameworks. [ABSTRACT FROM AUTHOR]

Biochars have received much attention as efficient adsorbents for water pollutants. Besides, the chemical treatment of biochars performed to increase the adsorption capacity usually causes secondary chemical pollution and increases the cost of the process. The biomass feedstock utilised in biochar preparation impacts significantly the surface properties and adsorption capacity. Thus, the need to prepare new biochars from new feedstock with potentially high uptake capacities. Herein, we prepared new biochar (POBC) from Platanus occidentalis waste leaves (POL), which was utilised for the ultrasonic-aided adsorption of bromophenol blue (BRB) and thiazolyl blue tetrazolium bromide (TTB). The FTIR, SEM, EDX, TGA, BET, pHpzc, and elemental characterisations of POBC revealed potent surface characteristics desirable for efficient dye adsorption. An increase in the surface area from 14.31 m2/g to 31.94 m2/g and the pore volume from 0.0214 cm3/g to 0.0326 cm3/g was obtained after the conversion of the POL to POBC. Besides, the SEM images of POBC revealed a highly porous surface structure of the adsorbent. The Freundlich and pseudo-second-order model presented the best fit to the isotherm and kinetics based on the high coefficient of determination (R2 > 0.9) and low sum square errors (SSE < 0.31). The heterogeneous surface nature of POBC was inferred from the independent-oriented site model. The monolayer adsorption capacity of 45.03 mg/g and 48.8 mg/g were obtained for BRB and TTB, respectively. Thermodynamics showed an endothermic, feasible, and random uptake, and POBC displayed efficient potentials to be reused. The obtained results revealed that novel POBC is an efficient low-cost biochar with high adsorption capacity for dyes. [ABSTRACT FROM AUTHOR]

Background: Illicit substance use is common at music festivals. One could question whether festival attendees deliberately plan to take drugs at such events or whether their illicit (poly)drug use is provoked by specific circumstances, such as the presence of peers or a general belief that others are using drugs at the festival. Objectives: The present study implemented the prototype willingness model, which is a model that assesses whether illicit drug use at music festivals is rather a rational or a more spontaneous decision-making process. Results: A three-wave panel survey was conducted, questioning festival attendees before (n = 304, 60.86% males), during, and after music festival visits. In total, 186 people (59.68% males) between 18 and 55 years (M = 27.80 years; SD = 8.19) completed all three surveys, of which 62.9% had taken one or more different illicit substances at the festival. Positive attitudes toward illicit drug consumption were most firmly related to attendees' intentions to take drugs at festivals. Additionally, the more festival visitors identified themselves with the prototype of an attendee using drugs, the more likely they were to be willing to use them. The perceived presence of illicit substances at such events was also strongly related to the actual behavior. Conclusion: The findings suggest that illicit drug use at music festivals relates to both a rational choice and an unplanned one. [ABSTRACT FROM AUTHOR]

In a bid to develop efficient biochars, we prepared new biochar by the pyrolysis of Ipomoea batatas feedstock for the ultrasonic-aided adsorption of eriochrome black T (EBT) and celestine blue (CB) dyes. The characterisation of the Ipomoea batatas-derived biochar (IBBC) showed potent functional groups, good thermal stability, porous structure and a point of zero charge of 6.41. The pH of 2.0 and 7.0 was found to be optimum for the uptake of anionic EBT and cationic CB onto IBBC, respectively. A decrease in the surface area of IBBC from 96.35 m2/g to 48.43 m2/g and 32.11 m2/g was obtained after the adsorption of EBT and CB, respectively. Thermogravimetric analysis revealed high thermal stability of IBBC up to 350°C. The Energy dispersive X-ray (EDX) spectrum revealed carbon (52.6%), oxygen (24.5%) and potassium (7.1%) as the major component of the biochar. The elemental analysis showed carbon, hydrogen and nitrogen compositions of 55.4%. 2.6% and 1.2%, respectively. Moreover, a biochar yield of 36.2% was obtained. The adsorption of both dye molecules was well correlated by the Freundlich isotherm, supported by the Scatchard model analysis. Kinetics was well fitted to the film diffusion and pseudo-second-order models, while thermodynamics showed an endothermic and spontaneous dye uptake on IBBC. The adsorption capacity of the biochar for EBT and CB was 59.24 mg/g and 63.69 mg/g respectively. Percentage desorption of 87.5% for EBT and 82.3% for CB was achieved during regeneration of the dye-loaded biochar. Moreover, IBBC showed good potentials to be reused for adsorption. The results revealed the potentials of the novel biochar for efficient adsorption of both cationic and anionic dye species. [ABSTRACT FROM AUTHOR]

The prominent benefit of granite is owned to its physicochemical property and ubiquitous nature. Vast application of granite which also includes its use as an adsorbent in environmental remediation practice, can also be enhanced. To further enhanced the uptake capacity of granite, nanocomposite consisting of multiwall carbon nanotubes (MWCNTs) and granite was fabricated and further modified using Dialiumguineensestem bark extract. The structure and composition of pristine granite (PG) and modified nanocomposite granite (G) based material were examined and confirmed by the FTIR, Raman, TGA, SEM and XRD. Meanwhile, the specific surface areasof PG (1.268 m2/g) and G (16.57 m2/g) were obtained using the BET surface area analyser. The optimization step revealed that the uptake capacities of PG and G were dependent on solution pH, sorbent dose and contact time. Meanwhile, pseudo-second-order and Elovich kinetic models were noticed to best describe the data for the removal of Cr (VI) by PG and G. Equilibrium isotherm study revealed that Freundlich and Langmuir models fitted well to the experimental data obtained for the uptake of Cr(VI) onto PG and G respectively. Furthermore, electrostaticattraction betweentheDialiumguineense stem bark extract on the surface of G and Cr(VI) influenced the uptake of Cr(VI). On the other hand, the interaction between the plant extract and Cr(VI) may result in the attenuation of Cr(VI) via reduction to Cr(III). Finally, the thermodynamically favoured adsorptive process demonstrated high adsorbent reusability with good stability for Cr(VI) uptake. [ABSTRACT FROM AUTHOR]

Despite its potential importance, the computational chemistry of adsorption processes for wastewater treatment has received negligible attention. Exploring the literature shows several limitations in applying quantum chemistry to study adsorption processes in wastewater treatment. The choice of suitable functionals of density functional theory (DFT) is one of the critical limits of the current application of quantum chemistry in wastewater treatment. Therefore, in this work, we performed a benchmark study of sixteen DFT functionals (including dispersions) to select the most suitable one. The def2-TZVP basis set has been used with the sixteen DFT functionals. The sixteen DFT functionals are benchmarked to the CCSD(T)/CBS level of theory. We used four different pollutants (p-aminobenzoic acid, aniline, p-chloro phenol, and phenol) adsorbed on coronene to perform this benchmarking. In addition to the coronene and the pollutant, four explicit water molecules are used to consider the environmental effects. The results show that the functional MN15 and PW6B95-D3 have the lowest mean absolute deviation relative to the CCSD(T)/CBS adsorption energies. Overall, the functionals MN15, PW6B95-D3, ωB97X-V, M05-2X-D3, M05-D3, and M06-2X-D3 are recommended for studying the adsorption processes. [ABSTRACT FROM AUTHOR]

This study investigates the capacity of spent self-indicating silica gels modified with Harpephyllumcaffrum(wild plum) stem bark extract to remove hexavalent chromium from wastewater. The physicochemical properties of the adsorbents were assessed using FESEM, FTIR, PXRD, TGA and BET surface analyser. The batch adsorption technique was used to examine the capacity of spent self-indicating silica gel (SIPP) and modified spent self-indicating silica gel (SIP) to eliminate Cr(VI) from the aqueous solution. The uptake capacity of the sorbents was noticed to increase with increasing adsorbent dose, contact time and initial concentration of Cr(VI). On the contrary, the potential of SIPP and SIP were observed to decline with increasing solution pH, similarly as found for most Cr(VI) absorbents. However, the uptake capacity of the SIPP and SIP were noticed to be optimum at 0.05 g adsorbent dosage and 180 min contact time. Meanwhile, the kinetic behaviour of SIPP and SIP in the removal of Cr(VI) was best described by the Elovich kinetic model. Furthermore, the uptake of Cr(VI) onto SIP and SIPP was sufficiently described by the three-parameter isotherm Sips and Freundlich isotherms respectively. The Cr(VI) adsorption was endothermic, entropy-driven, and feasible. The application of Harpephyllum caffrumstem bark extract on SIPP as Cr(VI) adsorbent was significant and the reusability of the adsorbent portrayed the capacity of SIP to adapt to a full-scale wastewater treatment practice. [ABSTRACT FROM AUTHOR]

Given the potential impact of climate change on amphibians, there is a need to establish baseline phenological data for vulnerable species and to investigate their responses to changing climatic conditions. We recorded vocalisations of Hewitt's ghost frog Heleophryne hewitti in the Baviaanskloof World Heritage Site, South Africa, to investigate its breeding phenology and vocalisation behaviour. Our objectives were to: 1) characterise seasonal and diel vocalisation patterns, 2) examine relationships between environmental variables and calling behaviour and 3) evaluate the effectiveness of acoustic recording as a monitoring technique. We employed automatic vocalisation recognition software to detect calls and used hurdle regression to model the relationships between environmental variables and the number of calls produced. Our study confirmed that H. hewitti is a seasonal prolonged breeder, with reproductive activity occurring from early to late spring. We found that while relative humidity seemed to influence the probability of calling, none of the weather variables appeared to have a strong influence on the number of calls produced. Acoustic monitoring combined with automatic vocalisation recognition has proven to be a viable technique for monitoring this species. Further investigation of cues for breeding initiation is required to understand the impacts of climate change on this species. [ABSTRACT FROM AUTHOR]

Pathology-supported genetic testing (PSGT) enables transitioning of risk stratification from the study population to the individual. We provide an overview of the translational research performed in postmenopausal breast cancer patients at increased risk of osteoporosis due to aromatase inhibitor therapy, as the indication for referral. Both tumor histopathology and blood biochemistry levels were assessed to identify actionable disease pathways using whole exome sequencing (WES). The causes and consequences of inadequate vitamin D levels as a modifiable risk factor for bone loss were highlighted in 116 patients with hormone receptor-positive breast cancer. Comparison of lifestyle factors and WES data between cases with vitamin D levels at extreme upper and lower ranges identified obesity as a major discriminating factor, with the lowest levels recorded during winter. Functional polymorphisms in the vitamin D receptor gene contributed independently to therapy-related osteoporosis risk. In a patient with invasive lobular carcinoma, genetic counseling facilitated investigation of the potential modifying effect of a rare CDH1 variant co-occurring with BRCA1 c.66dup (p.Glu23ArgfsTer18). Validation of PSGT as a three-pronged pharmacodiagnostics tool for generation of adaptive reports and data reinterpretation during follow-up represents a new paradigm in personalized medicine, exposing significant limitations to overcome. [ABSTRACT FROM AUTHOR]

Participatory action research (PAR) is a form of community-driven qualitative research which aims to collaboratively take action to improve participants' lives. This is generally achieved through cognitive, reflexive learning cycles, whereby people ultimately enhance their wellbeing. This approach builds on two assumptions: (1) participants are able to reflect on and prioritize difficulties they face; (2) collective impetus and action are progressively achieved, ultimately leading to increased wellbeing. This article complicates these assumptions by analyzing a two-year PAR project with mothers of disabled children from a South African urban settlement. Participant observation notes, interviews, and a group discussion served as primary data. We found that mothers' severe psychological stress and the strong intersectionality of their daily challenges hampered participation. Consequently, mothers considered the project 'inactionable'. Yet, many women quickly started expressing important individual and collective wellbeing transformations. To understand these 'unlikely' transformations, a feminist relational account, in particular, that of relational wellbeing, proves essential. We reflect on the consequences of these findings for the dominant PAR methodology and operationalization, and propose to sensitize future PAR with marginalized women by employing relational wellbeing as an overarching ontological awareness. [ABSTRACT FROM AUTHOR]

This study compared four South African sheep producing districts relative to each other and a common metafrontier to analyse within and between group efficiency and explored what could be learnt from this technique compared to simple frontiers. A sample was compiled from sources that were previously successfully used in local benchmarking exercises, and despite very modest sample sizes at the group level and minimal information on how groups differ, the group models performed adequately while the meta-model performed very well. The results revealed that while within group performances were comparable across districts, there were huge differences in between group performance. These differences are partly attributable to natural resource endowments, but institutional arrangements also contribute significantly to local success. This suggests that to achieve rural regeneration public–private partnerships are necessary to address this issue. State support is insufficient and producer organisations have a major role in promoting institutional innovation. [ABSTRACT FROM AUTHOR]

In response to the 2015 paper by Henderson published In Journal of Agricultural Economics, this case study of dairy farmers in Eswatini, this case study of dairy farmers in Eswatini tests the explanatory power of two hypotheses to explain the inverse relationship between farm size and productivity. To this end, we fit a stochastic frontier production function with inefficiency effects. We find that dairy farmers who use hired labour are significantly less efficient than those who use own and family labour. This supports the labour market imperfections hypothesis. To test the technical efficiency hypothesis, we segment our sample into small, medium and large farmers based on the number of cows in milk. We find that small farmers are the most efficient (78.5%), followed by medium (75.9%) and large (75.1%) farmers, but the differences are not statistically significant. This supports Henderson's finding that differences in efficiency affect productivity but not enough to disqualify labour market imperfections as the principal explanation for the inverse relationship. [ABSTRACT FROM AUTHOR]

This study conducts a critical race theoretic (CRT) reading of interviews with contractually-employed teaching assistants (facilitators). Facilitators are tasked with actively engaging small groups of first-year students in analyses of post-colonial literature. During the interviews, facilitators described the frustrations and discomfort they encounter while discussing racism and while assessing students' essays on the subject. Using CRT, this study examines how facilitators respond to what they construe as: (1) resistance from some students racialised as white, and (2) a perceived eagerness from students racialised as black to set experiential knowledge of racialised inequalities in conversation with the literature under study. [ABSTRACT FROM AUTHOR]

In this work, we have studied the microsolvation of phenol in water. We started by identifying initial configurations of phenol-water clusters using classical molecular dynamics. The configurations are optimised at the ωB97XD/aug-cc-pVDZ level of theory. To understand the interaction between phenol and the solvating water molecules, we performed a quantum theory of atoms in molecules (QTAIM) analysis. The results show that the structures of phenol-water clusters are similar to those of neutral water clusters. The QTAIM analysis shows that the structures of phenol-water clusters are stabilised by strong OH··· O hydrogen bondings, weak CH··· O hydrogen bondings, and OH ⋯ π bonding interactions. The located structures of phenol-water clusters have been used to calculate the absolute hydration free energy and enthalpy of phenol for temperatures between 20 and 400 K. The hydration energies are calculated using the cluster continuum solvation model. It has been found that the explicit solvation has negligible effects on the hydration free energy and enthalpy of phenol. Furthermore, the hydration free energy of phenol is found to be linearly varying with increasing temperature, while the hydration enthalpy is found to be temperature independent. The estimated hydration free energy of phenol is slightly underestimated as compared to a previously reported experimental estimate. [ABSTRACT FROM AUTHOR]

To date, research on effects of prenatal alcohol exposure (PAE) has focused on a broad range of cognitive impairments, but relatively few studies have examined effects of PAE on development of reading skills. Although PAE has been linked to poorer reading comprehension, it remains unclear whether this impairment is attributable to deficits in phonological processing, word reading, oral language skills, and/or executive functioning. A comprehensive reading battery was administered to 10 adolescents with fetal alcohol syndrome (FAS); 16 with partial FAS; 30 nonsyndromal heavily exposed; 49 controls. PAE was related to poorer reading comprehension but not to single-word reading or phonological processing, suggesting that the mechanics of reading are intact in adolescents with fetal alcohol spectrum disorders at this age. PAE-related impairment in reading comprehension was mediated, in part, by deficits in mastery of oral language skills, including vocabulary, language structure, and verbal fluency. These results are consistent with research showing that reading comprehension in adolescence relies increasingly on linguistic comprehension abilities, especially once word reading becomes automatic and text complexity increases. Our findings suggest that reading-impaired adolescents with PAE will benefit from intervention programs targeting vocabulary knowledge, language structure, verbal fluency, and reading comprehension skills. [ABSTRACT FROM AUTHOR]

Diabetes self-management education (DSME), a prerequisite for diabetes care, is mostly unstructured and inaccessible in the public health sector in South Africa (SA). Patient education is often delivered by healthcare professionals (HCPs) with limited time and proficiency, resulting in preventable errors with insulin administration. A study was undertaken to assess the knowledge of HCPs on the practical aspects of insulin administration and it was hypothesised that their expertise was insufficient. The unmet needs of DSME often transpire when preventable errors with insulin administration become clinically evident at higher levels of care. A prospective, descriptive study of HCPs' knowledge before and after attending a 'Diabetes 101' workshop was performed. Four workshops at Tygerberg Hospital (TH) and Worcester Provincial Hospital (WPH) were assessed between 2016 and 2019. A total of 146 participants completed a questionnaire before and after the workshops. Knowledge was scored on the correct responses per question and overall. The mean pre- and post-test scores were compared using two sample t-tests. Chi-square tests were used to analyse differences between pre- and post-training responses. Of 146 participants, the majority were medical doctors (n = 116; 80%), mostly junior (n = 75; 65%) with 21% nursing practitioners. Before training there were significant deficiencies identified with only 3 of the 19 question items answered correctly by more than 50% of HCPs. The greatest knowledge deficits were with regard to insulin re-suspension and the injection technique and priming of the insulin pen. Following training there was a significant improvement between the pre-test mean percentage score of 36.0% (15) and post-test mean percentage score of 68% (16) (p < 0.001). Knowledge on the practical aspects of insulin administration is insufficient amongst HCPs but improved after structured education. Further research is needed to assess the long-term retention of knowledge and the impact of knowledge translation into clinical care. [ABSTRACT FROM AUTHOR]

Critical whiteness studies (CWS) holds that challenging systemic racism in higher education must include scholarly attention to the everyday conditions under which students engage and produce knowledge about racism. This study examines the context of tutorials on postcolonial literature in a historically-white South African Department of English. Using individual interviews with contractually-employed Tutors, I map how these Tutors assign meaning to discomforting experiences and how they manage their own intersectional subjectivities while engaging undergraduates on systemic racism via postcolonial literature. Specifically, many students attempted to explore marginalization by grounding their essays in lived experiences of material deprivation. How Tutors' responses might be read within CWS is a core concern of this article. [ABSTRACT FROM AUTHOR]

Thermodynamics properties as well as infrared spectra of liquids can be determined using the quantum cluster equilibrium (QCE) theory. The QCE theory requires the knowledge of the structures of the clusters formed by the solvent molecules. In prelude to this determination, in this work, we studied the non-covalent bondings, the structures and the temperature-dependence of the clusters of dimethylformamide (DMF) from dimer to tetramer. To perform this study, we used classical molecular dynamics to sample initial geometries of DMF clusters. Then, optimisation of the geometries is carried out at the MP2/aug-cc-pVDZ level of theory. Besides, we carried out a quantum theory of atoms in molecule analysis. The results show that the structures of the DMF dimer exhibit a stacking configuration, and mainly stabilised by CH··· O hydrogen bondings. For the DMF trimer and DMF tetramer, the structures exhibit an amorphous behaviour. Moreover, it has been found that the CH··· O hydrogen bondings are the main non-covalent bondings in DMF clusters. CH··· C, CH··· N, N··· O, N··· C, C··· O and H··· H bonding interactions are also located in the studied DMF clusters. In addition, the temperature-dependence study shows that only isomers with relative energy within ∼ 1.0 kcal/mol have meaningful contribution to the population of DMF clusters. [ABSTRACT FROM AUTHOR]

Volatility is one of the measures of risk within the financial markets. GARCH modelling involves important volatility forecasting methodology and is widely used in finance. It is important to be able to forecast volatility since volatility has an impact on financial portfolios and the risk hedging methodology followed by financial companies. This study investigates the behaviour of parameter estimates and volatility forecasts of GARCH models over time, using a rolling window estimation procedure. Three GARCH models, the Symmetric GARCH, GJR-GARCH and E-GARCH models, are compared. The dataset used in the study comprises of the JSE All-Share index. This index is divided into two different periods, namely, a tranquil financial period and a turbulent financial period. Different factors influence the performance of GARCH models and consequently determines which GARCH model is the most suited for certain circumstances. These factors are: the sample window period, forecasting horison, the financial period and the underlying distribution of the log returns. [ABSTRACT FROM AUTHOR]

Subacute thyroiditis is a granulomatous inflammatory disorder often triggered by a preceding viral infection. Patients typically present with complaints of anterior neck pain associated with a tender enlarged thyroid gland. The coronaviruses have never before been implicated in the aetiology of subacute thyroiditis. It is postulated that the pathogenesis related to thyroid disease in Coronavirus disease 2019 (COVID-19) is multifactorial. Contributory factors include effects of the virus-related cytokine storm and direct action of the virus on SARS-CoV-2 receptors in the thyroid. This article further reviews the association between thyroiditis and COVID-19. The clinical characteristics, diagnostic workup and management of a patient who presented with subacute thyroiditis following COVID-19 are discussed. Furthermore, complications are entertained and suggestions for the management of thyroiditis following COVID-19 are provided. [ABSTRACT FROM AUTHOR]

This study presents a novel way to measure the contribution of private extension to farm productivity for club data. Club data refers to any convenience sample obtained from a study group, consulting firm, cooperative or producer organisation. The study develops a stochastic frontier production function model with the inefficiency effects of pasture-based dairy farming in the Eastern Cape, South Africa. The analysis for 2012–2018 involves 49 adopter farms, and controls for inter-calf period, nutrient use efficiency and the amount of extension contact. Results are robust to functional form specification and there is no evidence of frontier-shifting technical progress for the Cobb Douglas or translog model, but there is a clear productivity benefit to engaging with the private extension service provider working locally (adoption). Productivity rises at 0.91–1.06% p.a. over time and by 1.54–1.62% p.a. with each extra year of the extension. Large farms close to the private extension provider's base of operations benefit most from being in the group. This case study is important because it documents productivity growth in the period since 2010 and puts the effect of extension on productivity growth back on the local research agenda. [ABSTRACT FROM AUTHOR]

Increased bone resorption is a well-described consequence of primary hyperparathyroidism (PHPT). In South Africa, little is known about the impact of PHPT on skeletal health. To determine the prevalence of decreased bone mineral density (BMD), vertebral fractures and osteitis fibrosa cystica in patients with PHPT who underwent parathyroidectomy. Retrospective study of patients who underwent parathyroidectomy for PHPT at Tygerberg Hospital in Cape Town, from January 2010 to December 2019. Clinical, biochemical and BMD parameters are described. Final analysis included 56 patients (median age 63.5 years; 80.4% female). Initial calcium, parathyroid hormone (PTH) and 25-hydroxyvitamin D (25[OH]D) levels were 2.93 mmol/l, 19.4 pmol/l and 34.0 nmol/l, respectively. Of the total cohort, 71.4% had decreased BMD. The prevalence of osteoporosis and osteopenia in postmenopausal women and men ≥ 50 years was 50.0% and 39.1% respectively; low bone mass for age in premenopausal women and men < 50 years was 20.0%. Vertebral fractures were seen in 21.2% of patients on radiography. Osteitis fibrosa cystica was present in five patients (9.6%). PTH levels were significantly elevated in patients with osteoporosis compared with those with normal BMD (36.4 vs. 16.1 pmol/l; p = 0.02). Two-thirds of patients who underwent parathyroidectomy for PHPT had decreased BMD, with osteoporosis present in 50% of postmenopausal women and older men. One in five had vertebral fractures. These findings underscore the importance of skeletal assessment in the management of PHPT. [ABSTRACT FROM AUTHOR]

The association between hyperemesis gravidarum (HG) and abnormal thyroid function is well known. The prevalence, aetiology and course of thyrotoxicosis in women with hyperemesis gravidarum (HG) were studied. Women admitted for HG, who underwent thyroid function evaluation between 1 August 2016 and 30 April 2019, were studied. Laboratory data included baseline human chorionic gonadotropin (hCG) and baseline (t1), discharge (t2) and follow-up (t3) thyroid function tests (thyroid stimulating hormone [TSH] and free thyroxin [fT4]). Available TSH receptor antibody status was assessed. Eighty-two patients were included. The incidence of thyrotoxicosis was 49% based on local laboratory TSH range and 48% if trimester-specific ranges used. In the majority of normal pregnancies, thyrotoxicosis was hCG-mediated (72.5%), 15% were confirmed to have Graves' disease and 12% had a molar pregnancy. Very high fT4 levels (> 40 pmol/l) at baseline [t1] were documented in 24% of women with hCG-mediated thyrotoxicosis. Clinical features were absent in a third of women with Graves' disease and the diagnosis was reliant on positive antibody status. Free T4 values declined from (t1) to later in gestation (t3) (p < 0.001). The incidence of thyrotoxicosis in women with HG is high. Free-T4 values decrease with clinical stabilisation of HG, suggesting a contribution of dehydration to the large variation in baseline fT4 measurements. Testing for TSH-receptor antibodies should be considered in women with TSH < 0.01 pmol/l and persistent fT4 elevation on follow-up. Final review of thyroid function should be performed after 15 weeks' gestation. [ABSTRACT FROM AUTHOR]

Pre-existing diabetes mellitus (DM), hyperglycaemia and obesity emerged as prognostic factors in severe Coronavirus disease 2019 (COVID-19). To date, no published South African studies report on the incidence, presentation and outcomes of DM and diabetic ketoacidosis (DKA) during the COVID-19 pandemic. To reflect on the diagnosis, management, obstacles to care and outcome of four patients who were admitted to Tygerberg Hospital, Cape Town, South Africa. The outcome of these cases that presented consecutively with DKA and COVID-19 between May and July 2020 are discussed, the presentation, management and long-term considerations with specific reference to DKA and COVID-19 are reviewed. Three of the four patients had newly diagnosed DM. These patients presented with non-specific symptoms and signs leading to a diagnosis of both DKA and COVID-19. The single surviving patient in this series was known to have pre-existing DM but discontinued his insulin upon becoming unwell. One patient required insulin therapy at the time of initial presentation a week or two prior to the current admission but received metformin instead. She was diagnosed with COVID-19 after having poor glycaemic control for over one week, after which insulin was initiated. Ultimately she died as a result of severe hypokalaemia. One patient primarily had respiratory complaints, severe COVID-19 pneumonia and received concomitant dexamethasone. Glycaemic control in this patient was complicated by both hypo- and hyperglycaemia. These cases highlight the management challenges faced by many developing countries, and identify the missed opportunities in persons presenting with COVID-19 and hyperglycaemic emergencies. [ABSTRACT FROM AUTHOR]

This study presents the fabrication of nanocomposite for the sequestering of Cr(VI) from solution. The nanocomposites were obtained from the molecular sieve and functionalized multiwall carbon nanotubes and further modified with Pentaclethra macrophylla (oil bean tree) stem bark extract. The pristine molecular sieve (MS) and the modified nanocomposite [Pentaclethra macrophylla stem bark extract anchored on molecular sieve (SMP)] adsorbent were characterized by the FTIR, FESEM, XRD, BET, and TGA techniques. The batch adsorption experiment revealed an agitation time of 120 min, 0.02 g dosage, and sorbate pH of 2.0 as optimum conditions for effective use of MS and SMP. Under these conditions a maximum monolayer capacity (qmax) of 135.5 mg g−1 was obtained for SMP, a value that is better compared to many other related absorbent materials. The uptake of Cr(VI) onto MS and SMP was best described by pseudo-first-order and Elovich kinetic models respectively. Meanwhile, the Freundlich model was noticed to sufficiently describe the isotherm data obtained for MS and SMP. The adsorption of Cr(VI) onto MS and SMP was spontaneous, endothermic, and entropy-driven. The reusability of the nanocomposite and its efficient Cr(VI) removal, present SMP as a potent adsorbent for the sequestration Cr(VI) from aqueous solution. nsufficient innovative research on the sequestration of Cr(VI) from the aquatic ecosystem has made Cr(VI) a recalcitrant water contaminant that often affects water sources. In this work, a novel plant anchor-nanocomposite was fabricated from the spent molecular sieve, multi-walled carbon nanotubes, and the extract from the stem bark of Pentaclethra macrophylla. It was envisaged that due to the phytochemical constituent of the modifier, this nanocomposite could also act as potent adsorbents for the treatment of Cr(VI) polluted water. To the best of our knowledge, the application of Pentaclethra macrophylla stem bark extract as a modifier for the green fabrication of nanocomposite has not been reported. The resulting composites showed good uptake capacity for Cr(VI) as well as efficient reusability. [ABSTRACT FROM AUTHOR]

In premenopausal women, bone mineral density measurement by dual-energy X-ray absorptiometry should not be used as the sole guide for diagnosis or treatment of osteoporosis, universal screening with bone mineral density is not advised and the World Health Organization classification of bone status should not be applied. A diagnosis of premenopausal osteoporosis is reserved for those with evidence of fragility and may also be considered in women with low bone mass and an ongoing secondary cause of osteoporosis. Idiopathic osteoporosis in young women is rare. A thorough evaluation of secondary causes is indicated in all patients, with glucocorticoid treatment a common secondary cause of low bone mass and osteoporosis. Hypoestrogenism may be the primary cause of low bone mass and contribute to excessive bone loss in many conditions associated with premenopausal osteoporosis, and should be treated unless contra-indicated. The mainstay of treatment in premenopausal females with low bone mass includes risk factor reduction, advocating a healthy, active lifestyle and optimal treatment of secondary causes of bone loss. The safety of bone-specific therapy, especially long term and during pregnancy, remains uncertain. Bisphosphonates, teriparatide, denosumab and estrogen treatment increase bone density in premenopausal women with osteoporosis, but there are no study data confirming short-term fracture prevention with use of these agents. [ABSTRACT FROM AUTHOR]

An editorial is presented on exploring visual storytelling as a method of coming to terms with grief, loss, and bereavement. Topics include shared by the articles showing methods of storytelling, notions of narrativity, historicity, and temporalities; and engaging histories of violence and trauma such as the imprisoning, torture, and murder of Greek citizens.

Metastasis of a neuroendocrine tumour (NET) to the orbit is a rare occurrence, with published data limited to a few case reports. Orbital involvement usually presents with proptosis and decreased ocular mobility. Timing, in relation to the presentation of the primary tumour (PT), varies. The authors report a case of a 58-year-old female whose clinical presentation of orbital metastases preceded clinical suspicion of a midgut NET. Her presentation was with severe headaches and bilateral ptosis, histologically proven to be due to orbital muscle infiltration. The PT location was determined from the histopathological markers on orbital muscle biopsy, which suggested a gastrointestinal origin. Abdominal computed tomography (CT) was in keeping with a midgut NET with features characteristic of a desmoplastic reaction. Additional CT findings were widespread metastases, corroborated by nuclear imaging. The patient developed carcinoid syndrome and subsequently underwent surgical resection of the PT due to acute bowel obstruction. Her carcinoid symptoms and ocular findings improved on continued somatostatin receptor analogue therapy, but she sadly died within one month following surgery. [ABSTRACT FROM AUTHOR]

A low-cost adsorbent (Detarium senegalense stem bark extract coated shale (DSMS)) comprising pristine shale (PSH) coated with D. senegalense stem bark extract was prepared and utilized for the adsorption of Cr(VI). The DSMS and PSH were characterized by the SEM, XRD, FTIR, EDX, TGA, and BET. The batch adsorption experiment results showed that DSMS exhibited an excellent ability to adsorb chromium with a maximum removal occurring at pH 2, dosage of 0.05 g and 180 min contact time. The adsorption process was best described by the pseudo-second-order for DSMS and Elovich model for PSH which depicts chemisorption as the major mechanism responsible for the uptake of Cr(VI) onto the adsorbents. Langmuir model provided the best fit to the isotherm analysis on both materials. The maximum adsorption capacity of DSMS and PSH were 64.98 mg g−1 and 29.97 mg g−1 respectively. The thermodynamics revealed that the adsorption of Cr(VI) was feasible, endothermic and entropy driven. Furthermore, after five cycles of reuse, both DSMS and PSH demonstrated effective regeneration and reusability for Cr(VI) uptake. The structural properties, reusability, and high adsorption capabilities of DSMS indicate that they could be used as low-cost adsorbents in large-scale Cr(VI) wastewater treatment. Novelty statement Plant extracts are packed with a variety of polyphenolic compounds, such as aldehydes, alcohols, carboxylics, ethers, ketones, and phenols which contains several functionalities useful in the adsorption of toxic metals. Despite this, research on the use of plant extracts in the modification of adsorbent materials for enhanced adsorption is rare. This study reports for the first time the use of Detarium senegalense stem bark extract coated shale adsorbent for the efficient uptake of Cr(VI) ion. [ABSTRACT FROM AUTHOR]

An earlier study of district-level agricultural total factor productivity in the Western Cape province of South Africa Conradie et al. (2009a, b) is extended to include eleven Northern Cape districts that in combination make up the Karoo. Tornqvist Theil total factor productivity (TFP) indices are calculated using accounting data from 10 years of the farm census between 1949/50 and 2001/2. The Northern Cape districts experienced the same general productivity decline as those of the Western Cape's Central Karoo. Both parts of the broader Karoo region show a similar mean rate of decline. However, the reasons for this are different, with developments in irrigation systems a major factor. [ABSTRACT FROM AUTHOR]

An introduction is presented in which author discusses articles on topics including focuses on human conceptions and experiences of time, space and place as told in and through film, video, installation, photography and found and fashioned objects.

This research evaluated the adsorption of celestine blue (CB) onto a novel Solanum tuberosum waste-magnetite nanocomposite (Mt@STB), prepared by an ecofriendly impregnation of magnetite (Mt) nanoparticles onto Solanum tuberosum waste (STB). The adsorbents characterization revealed that Mt@STB had a surface area (18.92 m2/g), pHpzc (7.55), porous morphology as well as suitable functional groups for efficient sequestration of CB onto the composite. The SEM, XRD, and EDX showed successful incorporation of 31.21 nm average size Mt nanoparticles on Mt@STB. Faster kinetics of CB sequestration from the wastewater was obtained for Mt@STB (100 min) compared to STB (140 min). Among four isotherm models, the Langmuir exhibited the best fit with R2 > 0.9971 and sum square errors (SSE) < 0.0151. The pristine STB and Mt@STB composite showed maximum monolayer CEB uptake of 7.61 and 9.02 mg/g, as well as optimum removal of 73.8 and 84.7%, respectively. The pseudo-second-order model was more suitable in the kinetic description, while thermodynamics revealed a physical, spontaneous, and endothermic CB uptake. Besides, the efficacy of the composite for CB was confirmed from efficient regeneration over three adsorption/desorption cycles, which specified the viability of Mt@STB as a sustainable material for the decontamination of CB polluted water. NOVELTY STATEMENT The adsorption of dyes from wastewaters has been widely studied due to the harmful effects on the ecosystem. However, research on the removal of celestine blue (CB) dye is rare despite its wide use in the nuclear and textile industries. Until date, there is no report on the adsorption of CB on biomaterial via biosorption. Therefore, the biosorption behavior of CB is presently unknown. Hence, this study reports the biosorption of CB onto a biosorbent (Solanum tuberosum peel [STB]) in an attempt to understand its biosorption behavior. Besides, the impregnation of magnetite (Mt) nanoparticles has been reported to enhance the uptake of most adsorbents for dye. To the best of our knowledge, such magnetic nanoparticle impregnation of STB has not been reported. We, therefore, synthesized a novel biowaste-magnetite composite (Mt@STB) and evaluated its potentials for the uptake as well as its reuse for CB biosorption. [ABSTRACT FROM AUTHOR]

Manual assembly in the future Industry 4.0 workplace will put high demands on operators' cognitive processing. The development of mental workload (MWL) measures therefore looms large. Physiological gauges such as electroencephalography (EEG) show promising possibilities, but still lack sufficient reliability when applied in the field. This study presents an alternative measure with a substantial ecological validity. First, we developed a behavioural video coding scheme identifying 11 assembly behaviours potentially revealing MWL being too high. Subsequently, we explored its validity by analysing videos of 24 participants performing a high and a low complexity assembly. Results showed that five of the behaviours identified, such as freezing and the amount of part rotations, significantly differed in occurrence and/or duration between the two conditions. The study hereby proposes a novel and naturalistic method that could help practitioners to map and redesign critical assembly phases, and researchers to enrich validation of MWL-measures through measurement triangulation. Practitioner summary: Current physiological mental workload (MWL) measures still lack sufficient reliability when applied in the field. Therefore, we identified several observable assembly behaviours that could reveal MWL being too high. The results propose a method to map MWL by observing specific assembly behaviours such as freezing and rotating parts. Abbreviations: MWL: mental workload; EEG: electroencephalography; fNIRS: functional near infrared spectroscopy; AOI: area of interest; SMI: SensoMotoric Instruments, ETG: Eye-Tracking Glasses; FPS: frames per second; BORIS: Behavioral Observation Research Interactive Software; IRR: inter-rater reliability; SWAT: Subjective Workload Assessment Technique; NASA-TLX: National Aeronautics and Space Administration Task Load Index; EL: emotional load; DSSQ: Dundee Stress State Questionnaire; PHL: physical load; SBO: Strategisch Basis Onderzoek [ABSTRACT FROM AUTHOR]

Kassinula is a monotypic genus of small frog in the family Hyperoliidae, only represented by Kassinula wittei. This species morphologically resembles both Kassina Girard, 1853 and Afrixalus Laurent, 1944, and its taxonomic status has been debated for decades. It has previously been subsumed within Kassina, and is currently placed as a sister genus to Afrixalus, although it has not been included in any phylogenetic studies until now. This species is poorly represented in museum collections and is only known from fewer than 35 specimens from southern Democratic Republic of the Congo and adjacent Zambia. Newly collected material from central Angola, a range extension of 400–800 km west of previously known localities, allowed us to revisit the taxonomic placement of the genus with the aid of phylogenetic analysis and shed light on its geographic distribution, morphology and natural history. Although our phylogenetic analysis is limited to a single mitochondrial gene (16S), we place Kassinula in the subfamily Hyperoliinae and closely related to Afrixalus, with a high degree of confidence. Further phylogenetic studies are needed before formally synonymising Afrixalus with Kassinula. [ABSTRACT FROM AUTHOR]

This study presents a preliminary analysis of the productivity performance of a small group of mixed winter rainfall farms over the past decade. Results indicate that there has been no technical progress in the sector over the past decade and group members are falling further behind their own benchmark as time passes. Relative rankings have remained stable, with most of the group riding the peaks and troughs of good and bad years without breaking rank. There is clearly room for fresh thinking. Drought does not offer a simple explanation for the observed trends. This group's total factor productivity is inversely correlated with farm size despite evidence that their technology is increasing returns-to-scale. This is difficult to explain. Woolled sheep seems to be the solution to drought, but too much land under planted pastures lowers overall efficiency. There is much more investigation to do, including to cast the net wider so that a more sophisticated efficiency model can be fitted. There was no information on heat stress or rainfall variability, or the date of adoption of conservation agriculture, which is known to be a good strategy against unreliable rainfall. We also could not model the effect of farmers' skills and ambitions on their performance. The study's main contribution is to debunk the myths that rainfall places an absolute limit on performance and that a larger scale of operation is always beneficial. [ABSTRACT FROM AUTHOR]

We provide sufficient conditions for a map between projection lattices of semi-finite von Neumann algebras to be extended to a Jordan *-homomorphism. These conditions are sufficiently general for the procedures developed herein to have numerous fundamental applications in the study of isometries and composition operators on quantum symmetric spaces. Furthermore, these techniques are of independent interest, since they provide a partial generalization of Dye's theorem without the requirement that the initial von Neumann algebra be free of type I2 summands. [ABSTRACT FROM AUTHOR]

The African natricine genus Limnophis is represented by two species: Limnophis bicolor Günther, 1865 and Limnophis bangweolicus (Mertens, 1936). They are stout-bodied, semi-aquatic snakes that mostly feed on fish and amphibians, and occur from Botswana and Namibia in the south throughout most of Zambia and Angola to the Democratic Republic of the Congo in the north. We gathered new material from the ranges of both species in Angola and Zambia in order to examine their taxonomic status and identify any overlooked diversity. We constructed a phylogenetic tree, based on three mitochondrial genes (16S, cytb, ND4) and one nuclear gene (cmos), which includes the first DNA sequence data for Limnophis. Three well-supported lineages were identified, each representing separate species. The taxonomic status of the two currently recognised species is validated, and we describe a new species of Limnophis from north-eastern Angola. The new species is distinguished from the others by the combination of distinct ventral and lateral head colouration and patterning, differences in head and ventral scalation, and uncorrected pairwise genetic distances to both L. bicolor and L. bangweolicus of 5.4–8.1% in cytb, 6.1–8.4% in ND4 and 2.7–8.3% in 16S. [ABSTRACT FROM AUTHOR]

An integrative taxonomic review of the genus Boaedon in Angola is provided. A molecular phylogeny, based on 99 genetic samples for which the mitochondrial markers 16S rRNA have been sequenced, reveals 23 monophyletic species-level groups in Africa and indicates the presence of nine species in Angola. Based on both phylogenetic and morphological data, we revalidate and designate a neotype for B. angolensis, describe three new species for Angola (e.g. B. bocagei sp. nov., B. branchi sp. nov., and B. fradei sp. nov.), revalidate B. variegatus from its synonymy with B. lineatus and designate a lectotype for this taxon, and identify B. lineatus var. lineolatus as a junior synonym of B. variegatus. The taxonomic status of the recently described B. paralineatus from Central Africa is discussed with respect to the more inclusive B. lineatus group. Moreover, we report on a new country record for Angola, namely B. mentalis, which we elevate here to full species and discuss the taxonomic status of this species in southern Africa. Finally, we provide an identification key and updated distribution maps for all Boaedon species occurring in Angola, including the Cabinda enclave. [ABSTRACT FROM AUTHOR]

Behavioural trade-offs between foraging and thermoregulation result in negative relationships between diurnal body mass (Mb) gain and daily maximum air temperature (Tmax) in arid-zone birds. However, it remains unclear how these trade-offs are affected by habitat type or sexually dimorphic behaviour. Using the South African arid-zone endemic Red Lark (Calendulauda burra) as a model taxon and focusing solely on non-breeding adults, we evaluated predictions that a) time-activity budgets are more strongly affected by air temperature (Ta) than is the case for species occurring in arid savanna habitats with greater access to shaded microsites, and b) the effects of Tmax on diurnal Mb gain differ between males and females. Behavioural observations revealed an effect of Ta on activity, and sex differences in the temperature-dependence of resting and wing-spreading. Moreover, Mb data obtained from habituated larks trained to perch on an electronic balance revealed that in males, but not females, diurnal Mb gain was negatively related to Tmax, with diurnal Mb gain equivalent to average overnight Mb loss when Tmax = 33.5°C and zero diurnal Mb gain (i.e. net 24-hr Mb loss of ~ 5 %) when Tmax = 40.0°C. Under recent climate conditions, male Red Larks rarely, if ever, experienced consecutive days with Tmax > 40.0°C but, under an unmitigated climate change scenario, will experience 10–15 consecutive days per summer by the end of the 21st century. Our findings suggest that this threatened lark species is unlikely to persist across much of its current range by 2100. [ABSTRACT FROM AUTHOR]

Ovarian neoplasms are rare tumours of steroid cell origin. These tumours present clinically due to the associated excess production of either androgenic or oestrogenic gonadal steroid hormones. The clinical picture is dictated by the specific hormone(s) produced and influenced by the age of the patient. The case is a 59-year-old woman who presented with a five-year history suggestive of androgen excess. She underwent a hysterectomy and right-sided oophorectomy at age 28 years for dysfunctional uterine bleeding. Virilisation was confirmed on clinical examination and the testosterone excess biochemically localised to the ovaries. A left-sided oophorectomy was performed. The clinical picture and testosterone excess persisted after surgery. Follow-up radiological investigations identified adnexal material that on resection proved to be remnant ovarian tissue. Histopathology confirmed the presence of a steroid cell tumour within the remnant tissue. The biochemical androgen excess resolved and the clinical features improved dramatically. [ABSTRACT FROM AUTHOR]

Two cohorts of Likert scale risk data were subjected to rigorous principal component analysis to simplify the participants' risk rankings. This improves methodologically on the first Karoo risk analysis. More than 80% of the items and two-thirds of the participants overlap in these datasets, which made it possible to study the stability of these perceptions over the four years that elapsed between the surveys. Two-thirds of the items were factorable and the four common factors identified in the first cohort all persisted in the second cohort, which indicates stability. The four items added to the second survey created the opportunity to study how emerging structures differ when the lists change. The principal component analysis conducted on the longer list identified a new common concern about growing government control over private enterprise that came to light as a result of adding four extra items. Predation ranked as the number one risk in both surveys followed by drought. Labour and security were middling risks, market access a low risk and a lack of support from the local cooperative no risk at all. [ABSTRACT FROM AUTHOR]

Objectives: To assess the contribution of traditional and modifiable risk factors to the overall risk and prevalence of type 2 diabetes mellitus (T2DM) amongst health workers (HWs) in the public sector. Design: A retrospective analysis was performed on data obtained from 260 participants. Setting and subjects: HWs at Tygerberg Hospital, Western Cape attending the World Diabetes Day (WDD) metabolic screening and educational event. Outcome measures: The 10-year risk stratification for T2DM was calculated in all HWs attending the WDD event. This was based on the Finnish 'Test2prevent' diabetes risk calculator endorsed by the International Diabetes Federation assessing a set of well-established metabolic risk factors. Self-reported consumption of sugar-sweetened beverages (SSBs) was added to the questionnaire but did not add to the risk calculation. Results: The prevalence of known hyperglycaemia in this cohort is concerning (11%, n = 62). An additional 29 health workers were identified as at high risk to develop T2DM within 10 years. Consumption of SSBs and minimal physical activity were identified as modifiable targets for intervention. Conclusions: Education and lifestyle interventions are of paramount importance to ensure the metabolic health of HWs and their communities. Policies and guidelines focused on limiting unhealthy/obesogenic work environments are urgently needed. [ABSTRACT FROM AUTHOR]

Data collected during a multi-year study of farming in the district is updated to compile a land register. It identifies 30% of farmland by farm size and type and provides estimates of financial performance in each class. Three redistribution scenarios are considered – proportional redistribution, targeting large bona fide operations and targeting lifestyle land. The basic premise is still willing buyer willing seller. Changing the acquisition rules hardly affects the number of beneficiaries or the cost of redistribution but demonstrates that it is important not to overpay for lifestyle land. A redistribution plan for smallholder and settlement-orientated land users is added to the commercial plan according to Aliber's ratios. Commercial redistribution will involve 33 farms with a combined area of 2113 km2 at a total cost of between R352–384 million (using 2015 prices) and will include scope to provide for 132 commonage farmers and 660 settlement-orientated land users. Two-thirds of the land involved was for sale in January 2019 or could be enticed onto the market relatively easily because it has a low opportunity cost in agriculture and the plan would reach as many beneficiaries as there were indigent households in the district in 2017. [ABSTRACT FROM AUTHOR]

This article undertakes a discourse analysis of blame games surrounding the Overvaal High School controversy. It investigates the modes of reasoning that apportioned or deflected blame from key actors. Blame, in this context, involves culpability for escalating the racialised tensions that become a centrepiece of the debacle. A model of argumentation premised on topoi is applied to opinion pieces published online in reaction to the event. The primary aims of the article are to index dominant patterns in the argumentative structures that shaped these opinion texts, and to examine the way these arguments situate Overvaal in relation to systemic issues of racial equity. This agenda stems from the contention that online news, including opinion pieces, can play a cardinal role in constituting public knowledge of, and reactions to, divisive social events. [ABSTRACT FROM AUTHOR]

This study compares long established and more recently developed wine regions in South Africa. Deterministic efficiency frontiers produce measures of technical efficiency and technical change over time and the results for scale efficiency for each farm and each year show why the farm size results in previous studies are somewhat weak and contradictory. The scale efficiencies are very close to unity and switch from increasing to decreasing returns frequently over the period. This suggests scale efficiency is not important and although decreasing returns to scale dominates it lessens over time. The Malmquist TFP index is the product of technical change and efficiency change, but the usual contemporaneous version gives unreasonable results, as technical change and efficiency change move violently in opposite directions, making interpretation difficult. Since technological regression is not possible in such a short time period the sequential Malmquist is used as it prevents this occurrence. This shows that technological change has been very limited and that efficiency has also improved very little and thus the Malmquist TFP index has also grown very slowly, which bodes ill for South Africa's competitive position. The differences between the old and new districts are minimal, but growth was slightly higher in the newer regions. [ABSTRACT FROM AUTHOR]

This article critiques the appropriation of diversity in blame games surrounding the Hoërskool Overvaal (Overvaal High School) controversy that seized media attention in January 2018. Relying on discourse analysis, the study builds on previous research into the discursive practices that structure the imputation of blame for social problems emanating from politically controversial events. For sampling, the study draws from a corpus of nineteen journalistic opinion pieces published by online news sites in reaction to conflict at Overvaal. Its examination unravels a particular construction of diversity in blame games around Overvaal by focusing on an exemplar that narrows the value diversity to two dimensions: the non-racialism achieved through cross-racial contact, and linguistic diversity as conducive to long-term advantages in the labour market. To advance these goals, the study theorises blame as a social practice that involves argumentation. Authors make propositions about blame-worthy individuals or groups, prior to substantiating these claims with reasons. Claims and reasons are bridged by underlying modes of reasoning that may involve taken-for-granted assumptions about social values, such as diversity. As one way of addressing the risk that such values can be reduced to floating signifiers, the study critically assesses a prominent pattern in the way diversity is constructed. [ABSTRACT FROM AUTHOR]