980 research outputs found
Die opleiding van stads- en streekbeplanners in Suid-Afrika
Agtergrond en die huidige posisie Die eerste kursus vir die opleiding van beplanners in die Republiek van Suid-Afrika is twintig jaar gelede aan die Universiteit van die W itwatersrand ingestel. Sowat agt jaar gelede het die Universiteit van Natal met ’n soortgelyke kursus begin en twee jaar daarna het die Universiteit van Pretoria hulle voorbeeld gevolg
Loss functions for structural flood mitigation measures
The paper aims at discussing the methodology used to develop loss functions for flood mitigation measures, using historic data of flood damage to infrastructure. The main determinants of the extent of damage are the size of the flood and the length of the infrastructure within the boundaries of the flood-line. In regression analysis, flood peak was used as the independent variable in the Cobb-Douglas functions to depict the relationship between damage and flood peak. The Mfolozi flood-plain in Northern KwaZulu-Natal served as the study area. Loss functions for infrastructure, for ex ante estimation of damage to infrastructure, were developed for inclusion in a flood damage simulation model (FLODSIM) developed by the Department of Agricultural Economics of the University of the Orange Free State in collaboration with the Water Research Commission. Loss functions were determined for spillways, levees, tramlines, public roads, drains and bridges.
WaterSA Vol.27(1) 2001: 35-3
Critical success factors for Six Sigma Design and deployment to compliment lean operational strategy towards Capability Maturity
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Inhibition of Brevibacterium linens by Probiotics from Dairy Products
Brevibacterium linens is an important species in dairy products rendering a specific taste and aroma to numerous smear ripened and blue veined cheeses due to proteolysis. However, the presence of the species in South African blue veined cheeses is undesirable and consumers demand the product void of the species. Accordingly, numerous methods including microbial inhibition using fungi and bacterial probiotic cultures with possible inhibitory effects were applied in an attempt to inhibit the species. None of the fungi, however, proved to be successful, whereas Lactobacillus rhamnosus and Bifidobacterium lactis, two typical probiotic species applied in dairy products, showed inhibitory effects against B. linens when tested using the spot-on-lawn assay
Revisiting Nitrogen Fertilisation Rates of Kikuyu and Kikuyu-Ryegrass Pastures
Irrigated pastures are used for dairy production in South Africa. Minimum-tillage and nitrogen (N) fertilisation are important management practices for kikuyu (Pennisetum clandestinum) and ryegrass (Lolium spp.) pastures. Nitrogen fertiliser application rates as high as 500 kg N ha-1 year-1 have been reported. Conventional tillage as well as cutting and removal of herbage material (opposed to removal through grazing) are the basis on which these fertiliser guidelines were developed. The current management practices have substantially changed the soil organic carbon and N stoichiometry. The aim of this study was to determine an optimum rate of N application of kikuyu and kikuyu-ryegrass pastures. Five fixed N fertiliser rates (0, 20, 40, 60 and 80 kg N ha-1 grazing cycle-1) were evaluated. Soil characteristics and pasture performance were monitored over a two year period. Nitrate concentrations and total mineral soil N were substantial, compared to the control, when more than 40 kg N ha-1 grazing cycle-1 were applied, leading to potential losses to the environment. Differences in biomass production were mostly due to seasonal variation, while N treatment effects within a season were generally small. As N treatments increased on both the study sites, the self-sown clover component decreased. Agronomic nitrogen use efficiency was similar across treatments and seasons on both sites, with the exception of winter in the first year on the kikuyu-ryegrass site. The results indicate that the soil could be saturated with N, at least to a point where herbage production response is minimal. A positive response in terms of crude protein was observed in some of the higher N treatments, but up to a point where it was no longer favourable for milk production. It is therefore concluded that the current N guidelines needs to be revisited as they pose a risk to the environment and farm economics
Concussion knowledge and attitudes among amateur South African rugby players
Background: The South African Rugby Union’s BokSmart programme currently educates coaches and referees on concussion. Rugby players are often more familiar with their teammates than the coach or referee. Therefore they are well-positioned to play a pivotal role in rugby safety if they have adequate knowledge to identify subtle signs and abnormal behaviour displayed by a concussed teammate. However, no programme focuses on concussion education among South African rugby players and there is a dearth of literature on concussion education programmes among rugby players which could lead to safer return to play (RTP) habits.Objectives: To evaluate South African rugby players’ concussion knowledge and attitudes/behaviours regarding RTP following a concussion.Methods: A descriptive, cross-sectional study was used. Participants (n=294) were divided into junior amateur high school (JAHS) (n=216) and senior amateur club (SAC) (n=78) players. The modified RoCKAS-ST questionnaire was used to evaluate their concussion knowledge index (CKI) and concussion attitudes/behaviours index (CAI) regarding RTP.Results: On average, 62% (JAHS) and 60% (SAC) of the CKI questions were answered correctly. JAHS participants correctly identified 66% of concussion symptoms, similarly to the SAC participants (63%), rendering similar (p=0.37) overall CKI scores when comparing the two groups. The CAI questions yielded similar (p=0.98) results between the groups, reporting safe responses in 66% (JAHS) and 67% (SAC) of the items.Discussion and conclusion: Junior and senior South African amateur rugby players lacked approximately one-third of essential concussion knowledge, which may lead to a display of unsafe attitudes/behaviours to concussion and RTP. Further research is warranted to inform educational programmes on concussion among rugby players.Keywords: post-concussion syndrome, rugby union, return to play, safety, South Afric
Concussion return-to-play behaviour of South African Rugby Union (SA Rugby) Youth Week players: a pilot study
Introduction: BokSmart has disseminated Graduated Return-to-Play (GRTP) guidelines for concussions management to all, but specifically coaches, in South Africa. Medical clearance before returning to play (RTP) is poorly adhered to in the GRTP steps. This study explored barriers to compliance with medical clearance prior to RTP.Methods: Players who suffered a concussion during the 2014/2015 South African Rugby Youth Week Tournaments were followed-up telephonically until RTP. Semi-structured interviews were conducted to explore enablers/barriers to seeking/not seeking medical clearance before RTP.Results: Of those who did not seek medical clearance (47%), 80% indicated that the player/parent or coach felt this was unnecessary. Of those who did seek medical clearance, 65% reported they were instructed to do so either by the tournament doctor who diagnosed the injury or by the school coach.Conclusion: Besides coaches, parents and medical doctors have an important influence on players’ RTP behaviour. The findings of this pilot study need to be repeated in a larger cohort.Keywords: injury management, head injury, youth, football, South Afric
Factors influencing the distribution of Cactoblastis cactorum, a biological control agent of Opuntia stricta in Kruger National Park, South Africa
Cactoblastis cactorum, a phycitid moth, has been used with considerable success as a biological control agent against several different cactus species in many parts of the world, including Opuntia stricta in Kruger National Park [KNP], South Africa. Although the moth has become widespread and abundant in KNP, its populations have not reached levels where it is able to provide the desired level of control on the alien species which has invaded more than 35 000 ha of the park and continues to spread. Although several factors, especially acquired predators and parasitoids, are known to curb the abundance of C. cactorum in South Africa, the extent to which this applies in KNP is unknown. Logistic regression and Canonical Community Analysis were used to determine the biotic and abiotic factors affecting the distribution and abundance of C. cactorum in KNP. To do this, maps of the ranges of the insect and host plant were constructed and integrated with other environmental features. The logistic regression showed that O. stricta density had no influence on whether or not C. cactorum was present in an area. The Canonical Community Analysis suggested that a high fire frequency, the herbicide control programme and the presence of small host plants may be important in limiting the distribution of C. cactorum, either directly or indirectly, through impacts on associated predators or parasitoids
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