’n Perspektief op die voorkoms van dissiplineprobleme in Afrikaanse skole

Discipline problems in Afrikaans schools – a perspective The aim of this article is to report on an investigation into the incidence and extent of discipline problems in Afrikaans schools, especially in the light of fundamental changes that have occurred during the past ten years within these schools. This report is also placed in the context of a reformational perspective on discipline, disciplinary problems and the role of educators in eradicating such problems. An empirical investigation was conducted, in which the experience of 76 principals of Afrikaans schools was probed by means of two questionnaires. The responses revealed that the overwhelming majority of principals opined that the discipline situation at their schools was either average or good, and that feelings of despondence and defaitism regarding discipline did not exist. In line with new official education policy, they had implemented new procedures, in order to address discipline problems. The incidence of disciplinary problems was not higher in multicultural schools. The incidence was, however, higher at urban than in rural schools. Parental involvement was identified as an essential factor in combatting disciplinary problems in schools. It was also found, on the basis of a Biblically-based view of education, that parents and other educators had a significant role to play in eradicating such problems

The weakening of eggshells of the laughing dove, Streptopelia senegalensis (Linn.)

Eggshells of Streptopelia senegalensis dating from 1899 to 1983 were studied to determine whether a change had occurred in the mass of the shells, the length section, breadth (width) section, thickness and index. A significant difference was determined in both mass and index of the more recent eggs (after 1957) compared with older eggs. The two groups of eggs represent periods prior and subsequent to the introduction of agricultural pesticides in southern Africa. Although no definite link has been established the results merit further experimental studies to determine whether the observed changes could be ascribed to the increased usage of agricultural pesticides

Floral development in Greyia flanaganii with notes on inflorescence initiation and sympodial branching

The aerial parts of Greyia flanaganii H. Bolus consist of a system of superposed monochasial shoots. The mature lateral inflorescences of this evergreen and probably most primitive species of Greyia Hook. & Harv. are primarily terminal. The flowers are adapted to ornithophily, basically diplostemonous and inclined to haplostemony. The 5 floral whorls essentially develop acropetally and alternately, but in flower buds with less than 10 stamens the carpels are epipetalous. The multilayered endothecium-like tissue and additional inner parenchyma form the criteria for considering the anther of Greyia as phylogenetically primitive. Similarities in floral morphogenesis of the Greyiaceae and Saxifragaceae sensu lato are discussed

Onderwys-/opleidingsvoorsiening en ekonomiese aanvraag

Education/training and economic demand Education systems and their output appear to be out of step with the demands of the economy in many countries, including South Africa. Massive education investment and expansion seem to have resulted, especially in developing countries, in schooled unemployment rather than economic development, modernisation and full employment. A historicalcomparative overview reveals how economically successful countries such as the United Kingdom, the United States of America, Germany, and (until recently) the new economic giants of South-East Asia and the Far East, succeeded in aligning education and training with the economy. In conclusion the implications of their strategies for South Africa are explored. A combination of the British and Singaporean models is recommended for South Africa. A warning is, however, sounded throughout that economic systems that do not adhere to the principles of human stewardship and responsible management should not be supported by education and training in their present forms. Those involved in education and training should rather call for reform of the systems that they are expected to support

Seasonal patterns of habitat use by insectivorous bats in a subtropical African agro-ecosystem dominated by macadamia orchards

We report on acoustic surveys of insectivorous bats conducted during seven months of the year using ANABAT recordings in two habitats (macadamia orchards and adjacent riparian bush) in a subtropical agroecosystem in northern South Africa. We defined two functional foraging groups of bats based on their echolocation calls: (i) open-air foragers (family Molossidae) having narrow-band, low-frequency, low duty cycle calls; and (ii) clutter-edge foragers (families Miniopteridae and Vespertilionidae), having broad-band, higher frequency, low duty cycle calls. Bat activity (number of bat passes) was not significantly influenced by habitat. Total bat activity and activity of both functional groups varied significantly between seasons, being highest in summer and autumn (coinciding with annual peaks in numbers of Twin spotted (Bathycoelia natalicola) and Green (Nezara spp) Stinkbugs, order Heteroptera, family Pentatomidae, and Macadamia Nut Borer moths, Cryptophlebia ombrodelta) and lower in winter and spring. No significant effect of moon phase was detected, either on total activity or activity of the two functional groups. We postulate that the significant pattern of seasonality of commuting and/or foraging activity of bats in macadamia orchards (which is more marked in open-air foragers) may be driven by the seasonal abundance of pest insects such as stinkbugs and Macadamia Nut Borer moths.The study was funded by a Niche-Area Grant of the University of Venda as well as a National Research Foundation (NRF) Grant for Incentive Funding of Rated Researchers.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2028hb2014Zoology and EntomologyMammal Research Institut

Selected risk factors for coronary heart disease in male scholars from the major South African population groups

A num.ber of risk factors for coronary heart disease (CHD) in 7 groups of South African male scholars aged between 15 and 20 years were surveyed. Selection of the groups was based on socioeconomic status and comprised urban and rural blacks, Indians of higher and lower socio-economic status, coloureds of higher and lower socio-economic status, and middle-class whites. Both Indian groups, both coloured groups and the whites had a much greater prevalence and severity of CHD risk factors than the two black groups. This held for total cholesterol, low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), the HDLC/LDLC ratio, apolipoprotein B, apolipoprotein A-I, insulin, fibrinogen and mass. One exception was lipoprotein a, levels of which were higher in both black groups. In general the CHD risk factor profile was worse in the higher socio-economic groups, and it also tended to be worse in urban than in rural blacks. These findings stress the need to reduce CHD risk factors in our developed populations and to prevent their emergence in our developing peoples

Treated Acid Mine Drainage and Stream Recovery: Downstream Impacts on Benthic Macroinvertebrate Communities in Relation to Multispecies Toxicity Bioassays

Research ArticleThe success and long term effectiveness of extensive and expensive engineering solutions to restore streams impacted by Acid Mine Drainage (AMD) is rarely tested. Concentrations of pollutants were measured in water along a longitudinal gradient from a stretch of the Tweelopie stream, South Africa, that receives pH-treated acid mine drainage (AMD) from an abandoned gold mine. The biotoxic effects of treated AMD were determined through macroinvertebrate biotic indices (SASS5) and a battery of toxicity bioassays. These included the L. sativa, A. cepa, D. magna toxicity and Ames mutagenicity tests, as well as an in vitro human liver cancer cell line HepG2. Even though the Tweelopie stream was moderately to severely degraded by multiple anthropogenic stressors, the impact of the treated AMD was masked by the improvement in the system downstream after mixing with the domestic wastewater effluent receiving stream, and subsequent further dilution as a result of the karst springs downstream. The general improvement of the system downstream was clearly shown by the decrease in the ecotoxicity and mutagenicity in relation to the in-stream macroinvertebrates. PCA multivariate analysis successfully displayed associations between the different environmental variables and the decrease in toxicity and subsequent ecosystem improvement downstream. This study indicated that environmental management of AMD remediation should consider long term assessment strategies, including multiple factors, to promote biological ecosystem recovery

Plant anatomy as a tool for evaluating the effect of different levels of nitrogen, plant population density, row spacing and irrigation on kenaf (Hibiscus cannabinus) fibre development

Kenaf (Hibiscus cannabinus) provides high-quality fibre that is used in papermaking, building materials and absorbents. The study aims were to conduct a proper anatomical study of fibre development in kenaf stems, and to investigate if the number of fibre wedges, fibre rings (layers) and fibre bundles can be used as a tool to determine fibre development response to different agronomic practices. The practices evaluated included different nitrogen levels (0, 50, 100 and 150 kg N ha−1) under both rainfed and irrigated conditions, as well as different combinations of plant population densities (300 000, 400 000, 500 000 and 600 000 plants ha−1) and row spacing (0.17, 0.34 and 0.50 m) under rainfed conditions. In most cases N, water and plant population density were the principal factors affecting the number of fibre rings and fibre bundles, but not the number of fibre wedges. Higher levels of N and more water increased the number of fibre rings and fibre bundles, whereas at higher plant population densities, these decreased. No clear trends were observed with regards to row spacing. The results of this study suggested that under local conditions, 150 kg N ha−1 applied in two splits, 300 000 plants ha−1 and 0.50 m row spacing was the optimal combination of agronomic practices in terms of fibre development per plant. This paper gives a more complete explanation of fibre development in kenaf and shows how plant anatomy can be used as a tool to assess fibre development.Sustainable Fiber Solution (SFS), the National Research Foundation (NRF) and Reconstruction and Development Programme (RDP).http://www.tandfonline.com/loi/tjps202018-06-22hj2017Plant Production and Soil Scienc

Spectroscopic imaging of the sun with MeerKAT: opening a new frontier in solar physics

Solar radio emissions provide several unique diagnostics to estimate different physical parameters of the solar corona, which are otherwise simply inaccessible. However, imaging the highly dynamic solar coronal emissions spanning a large range of angular scales at radio wavelengths is extremely challenging. At gigahertz frequencies, MeerKAT radio telescope is possibly globally the best-suited instrument at present for providing high-fidelity spectroscopic snapshot solar images. Here, we present the first published spectroscopic images of the Sun made using the observations with MeerKAT in the 880–1670 MHz band. This work demonstrates the high fidelity of spectroscopic snapshot MeerKAT solar images through a comparison with simulated radio images at MeerKAT frequencies. The observed images show extremely good morphological similarities with the simulated images. Our analysis shows that below ∼900 MHz MeerKAT images can recover essentially the entire flux density from the large angular-scale solar disk. Not surprisingly, at higher frequencies, the missing flux density can be as large as ∼50%. However, it can potentially be estimated and corrected for. We believe once solar observation with MeerKAT is commissioned, it will enable a host of novel studies, open the door to a large unexplored phase space with significant discovery potential, and also pave the way for solar science with the upcoming Square Kilometre Array-Mid telescope, of which MeerKAT is a precursor

Significant out-of-sample classification from methylation profile scoring for amyotrophic lateral sclerosis

We conducted DNA methylation association analyses using Illumina 450K data from whole blood for an Australian amyotrophic lateral sclerosis (ALS) case–control cohort (782 cases and 613 controls). Analyses used mixed linear models as implemented in the OSCA software. We found a significantly higher proportion of neutrophils in cases compared to controls which replicated in an independent cohort from the Netherlands (1159 cases and 637 controls). The OSCA MOMENT linear mixed model has been shown in simulations to best account for confounders. When combined in a methylation profile score, the 25 most-associated probes identified by MOMENT significantly classified case–control status in the Netherlands sample (area under the curve, AUC = 0.65, CI95% = [0.62–0.68], p = 8.3 × 10−22). The maximum AUC achieved was 0.69 (CI95% = [0.66–0.71], p = 4.3 × 10−34) when cell-type proportion was included in the predictor