Sportgeneeskunde, onkunde en sport

No Abstrac

Variability in the anthropometric status of four South African populations

Coefficients of variation (V) of 4 populations were compared for each of 11 parameters. Males differed significantly in cristal height and 3 skinfolds. It has been suggested that negroids vary more in relation to their means in cristal height because of the onset of differential growth of the lower limbs. Relatively large Vs in skinfold measurements of White and Indian boys, notably those of the trunk, arose because there were more obese individuals with extreme values in the White and Indian populations than in the Cape Coloured and negroid populations. In females, leg circumferences and subscapular skinfolds differed significantly. Leg circumference Vs of Indian females were probably enhanced as a result of variably high adiposity in the calf region. The presence of extreme values in obese girls of this group had been the cause of raised Vs in subscapular skinfold measurements. There appear to be three periods during which the Vs of males and females differed: males varied more than females at the ages of 6 and 7 years; then females varied more until between 13 and 15 years, when males again became more variable. White males, however, varied more than White females in skinfolds. This may be caused by the presence of extreme values at either end of the distribution graph of both 'over-optimal' nutrition and undernutrition. It is shown that confidence limits based on a central value of the standard deviation (a) do not take into account the increasing variability with age noted in most parameters in populations of growing individuals. In future studies, variability changes should be shown by placing polynomials into one of the categories described n this article.S. Afr. Med. J., 48, 643 (1974)

Anthropometric status of Pretoria children of four populations: Increases in cross-sectional samples

Total percentage increases per 10 years of growth and average triennial percentage increases were calculated for 11 anthropometric variables in males and females aged 6-15 years from four South African populations studied crossseetionally. The. increase of various measurements for each population was discussed and compared with that for the other populations; also, values for males and females were compared

Method and timing of grassland renovation affects herbage yield, nitrate leaching, and nitrous oxide emission in intensively managed grasslands

Managed grasslands are occasionally ploughed up and reseeded in order to maintain or increase the sward productivity. It has been reported that this renovation of grassland is associated with a flush of soil organic nitrogen (N) mineralization and with a temporary increase in soil mineral N contents. Here, we report on the effects of method and time of grassland renovation on herbage yield, nitrate (NO3 -) leaching and nitrous oxide (N2O) emission. Field experiments were carried out at three sites (two sandy soils and a clay soil) in the Netherlands for three years. Renovation of grassland increased the percentage of Perennial ryegrass from 48–70% up to more than 90%. However, averaged over three years, dry matter yields were higher for the reference (not reseeded) swards (on average 13.6 Mg ha-1 for the highest N application rate) than for the renovated grasslands (12.2–13.1 Mg ha-1 dry matter). Grassland renovation in April did not increase N leaching in comparison to the reference. However, renovation in September increased the risk of leaching, because mineral N contents in the 0–90 cm were in November on average 46–77 kg N ha-1 higher than in the reference. Contents of dissolved organic N (DON) in the soil were not affected by renovation. Renovation increased N2O emissions by a factor of 1.8–3.0 relative to the reference grassland. Emissions of N2O were on average higher after renovation in April (8.2 kg N2O-N ha-1) than in September (5.8 kg N2O-N ha-1). Renovation without ploughing (i.e. only chemically destruction of the sward) resulted in a lower percentage of perennial ryegrass (60–84%) than with ploughing (>90%). Moreover, N2O emissions were higher after renovation without ploughing than with ploughing. Clearly, farmers need better recommendations and tools for determining when grassland renovation has beneficial agronomic effects. Losses of N via leaching and N2O emission after renovation can probably not be avoided, but renovation in spring in stead of autumn in combination with ploughing and proper timing of fertilizer application can minimize N losses

Resource optimisation of a warehouse process through simulation modeling - Agrinet

In the distribution industry warehousing plays one of the most important roles in the distribution of products. It is therefore of utmost importance that a warehouse performs at optimum levels to ensure cost efficiency, in time delivery and productivity. All warehouses have opportunities for improvement; the opportunities just need to be identified. There are a significant number of methods and techniques to identify and solve problems within a warehouse. Some of these methods and/or techniques involve the elimination of bottle necks, which can increase the throughput volume of a warehouse and ultimately lead to an increase in profit. This project primarily consists of building a simulation model in order to determine the optimum number of resources required in the current bottleneck of the warehouse; the audit area.Thesis (B Eng. (Industrial and Systems Engineering))--University of Pretoria, 2012

The Acute versus Chronic Pain Questionnaire (ACPQ) and actual pain experience in older people

The Acute versus Chronic Pain Questionnaire (ACPQ) was applied to older people. Two groups emerged from an analysis of which an item of each pair (an acute and a chronic affective item) was considered to cause the most suffering. One group of subjects comprised those who expected to suffer more from one or more acute pain items (high-ACPQ group, n = 35). A second group emerged for whom none of the acute items was considered to be a burden (low-ACPQ group, n = 33). It was hypothesized that, compared to the low-ACPQ group, the subjects with high-ACPQ scores selected acute ACPQ-items due to a decline in the experience of chronic affective pain. This hypothesis predicted lower scores on the chronic ACPQ-items and lower scores on scales evaluating the subjects' own chronic affective pain. The results showed that, irrespective of the group, the chronic ACPQ-items were considered to produce the most burdens. However, compared with the low-ACPQ group, the high-ACPQ group reported experiencing significantly more pain from the acute ACPQ-items. Moreover, the latter group indicated suffering less pain from their own chronic pain conditions. The present findings suggest that the selection of one or more acute items of the ACPQ (high-ACPQ group) may point to an alteration in subjects' actual pain experience

What makes theological education "theological"? a South African story on the -integrity of theological education

David Tracy claims that the contemporary emergence of a sociological imagination is as crucial for theological self-consciousness as the earlier rise of historical consciousness among theologians. The authors are of the opinion that the rapid and fundamental social changes in South African society over the past few years have accelerated this "emergence of a sociological imagination" amongst South African theologians. In three sections, they point to three clusters of questions that have therefore become increasingly important, namely questions related to the growing awareness of the crucial role of social location or context, questions arising from a growing acknowledgement of public responsibility, and questions concerning the integrity of theological education, i.e. the question on what makes theological education "theological".Continued 2001 as 'Verbum et Ecclesia'Spine cut of Journal binding and pages scanned on flatbed EPSON Expression 10000 XL; 400dpi; text/lineart - black and white - stored to Tiff Derivation: Abbyy Fine Reader v.9 work with PNG-format (black and white); Photoshop CS3; Adobe Acrobat v.9 Web display format PDFhttp://explore.up.ac.za/record=b102527

Organische stof: onbemind of onbekend?

Deze studie inventariseert recente inzichten over organische stof in de bodem en inventariseert kennisvragen en -leemtes. De aandacht gaat uit naar mogelijke veranderingen en verlies van organische stof, daarmee samenhangende risico's , mogelijke reacties en waarnemingen van effecten van handelen. Een studie in opdracht van MPB Bilthove

Exploring an extensive dataset to establish woody vegetation cover and composition in Kruger National Park for the late 1980s

Woody plant cover and species composition play an important role in defining the type and function of savanna ecosystems. Approximately 2000 sites in the Kruger National Park (KNP) were surveyed by F.J. Venter over a period from 1985 to 1989, recording vegetation, soil and topological characteristics. At each of these sites (approximately 20 m × 20 m each), woody vegetation cover and species were recorded using a rapid, Braun-Blanquet classification for three height classes: shrub (0.75 m – 2.50 m), brush (2.50 m – 5.50 m) and tree (> 5.50 m). The objective of this study was to re-analyse the vegetation component of the field data, with a specific focus to provide a spatially explicit, height-differentiated, benchmark dataset in terms of species occurrence, species richness and structural canopy cover. Overall, 145 different woody species were recorded in the dataset out of the 458 species documented to occur in the park. The dataset describes a woody layer dominated by a relatively small number of widely occurring species, as 24 of the most common woody species accounted for all woody species found on over 80% of all sites. The less common woody species (101) were each recorded on 20 sites or less. Species richness varied from 12 to 1 species per site. Structural canopy cover averaged 9.34%, 8.16% and 2.89% for shrub, brush and tree cover, respectively. The dataset provides a useful benchmark for woody species distribution in KNP and can be used to explore woody species and height class distributions, as well as comparison with more recent or future woody vegetation surveys. Conservation implications: The results provided evidence that large-scale, woody vegetation surveys conducted along roads offer useful ecosystem level information. However, such an approach fails to pick up less common species. The data presented here provided a useful snapshot of KNP woody vegetation structure and composition and could provide excellent opportunities for spatio-temporal comparisons

Characterization and modeling of gain spectra of single-layer InAs/InP(100) quantum dot amplifiers

In this contribution we present the small signal net modal gain measurement results of single-layer InAs/InP(100) quantum dot amplifiers in 1.6 to 1.8 µm wavelength range. The material shows sufficient optical gain to be used in the long-wavelength optical coherence tomography. The modal gain has been observed as a function of current density and temperature. An improved rate equation model has been applied to analyse the measurements. A good fit of the theory to the measurements was obtained with a temperature dependent carrier injection efficiency which is below 2%