Die Romeins-Hollandse reg na 300 jaar gehandhaaf en versterk

„Driemaal het Rome aan die wêreld wette gedikteer, driemaal die volkere tot eenheid verbind”— met hierdie woorde begin een van die beroemdste juriste van die 19de eeu sy ewe beroemde werk oor „Die gees van die Romeinse reg”—„die eerste keer, toe die Romeinse volk nog in die volheid van sy krag gestaan het, tot eenheid van staat, die tweede keer, toe hy reeds ondergegaan was, tot eenheid van kerk, die derde keer, as gevolg van die resepsie van die Romeinse reg in die Middeleeue, tot eenheid van reg; die eerste keer met geweld van buite deur die mag van wapens, die ander twee keer deur die mag van die gees

Remarks on colitis: with special reference to its incidence and treatment in South Africa

The condition known as Colitis or Mucous Colitis is of frequent occurrence in general practice. Although much has been written on the subject, there are many points connected with the disease which need elucidation . During a period of 17 years general practice in South Africa I have had tinder my care a considerable number o f cases of Colitis of varying types and in the present theses I have attempted to give my views on the subject, based on my experience in South Africa . Let it be remembered that conditions, in some instances very primitive, differ materially from conditions in the old country. Owing to the open air life we find a race more sturdy constitutionally than in England. Facilities for successful treatment, owing to the distances, are also very variable in South Africa

Experiences in porting mini-applications to OpenACC and OpenMP on heterogeneous systems

This article studies mini-applications—Minisweep, GenASiS, GPP, and FF—that use computational methods commonly encountered in HPC. We have ported these applications to develop OpenACC and OpenMP versions, and evaluated their performance on Titan (Cray XK7 with K20x GPUs), Cori (Cray XC40 with Intel KNL), Summit (IBM AC922 with Volta GPUs), and Cori-GPU (Cray CS-Storm 500NX with Intel Skylake and Volta GPUs). Our goals are for these new ports to be useful to both application and compiler developers, to document and describe the lessons learned and the methodology to create optimized OpenMP and OpenACC versions, and to provide a description of possible migration paths between the two specifications. Cases where specific directives or code patterns result in improved performance for a given architecture are highlighted. We also include discussions of the functionality and maturity of the latest compilers available on the above platforms with respect to OpenACC or OpenMP implementations

House-dust mite species in Bloemfontein, South Africa

House-dust mites (HDMs) are an important source of allergens that are reputed to act as a trigger for atopic disease. Climatic conditions in parts of South Africa are not suitable for their proliferation, and there is doubt whether they occur on the Highveld. We studied whether HDMs occur in homes in Bloemfontein, Free State.Methods. Ten houses were sampled over a 1-year period. Dust was collected monthly or quarterly from a mattress, a bedroom floor and the living room floor of each house and examined for the presence of HDMs. Climate data were collected during the same period and a questionnaire was completed by home-owners to gather data on indoor factorsthat could influence mite proliferation.Results. HDMs were regularly found in 3 houses (30%). Dermatophagoides farinae was the dominant species (97.5%).The highest numbers were found in winter, when climatic conditions were the least favourable. Climatic conditions never met the requirements for active proliferation of the mites. Indoor factors that may have promoted mite proliferation in some houses were artificial heating (especially under-floor heating), en-suite bathrooms and lack of adequate ventilation during the winter months.Conclusion. HDMs do occur in central South Africa, owing to amicroclimate created indoors. Adequate ventilation, to reduceindoor humidity, should suffice to reduce mite numbers andprevent atopic symptoms induced by them

Accessibility in a Post-Apartheid City: Comparison of Two Approaches for Accessibility Computations

Many authors argue that issues related to interpretability, lack of data availability, and limited applicability in terms of policy analysis have hindered a more widespread use of accessibility indicators. Aiming to address these aspects, this paper presents two accessibility computation approaches applied to Nelson Mandela Bay in South Africa. The first approach, a household-based accessibility indicator, is designed to account for the high diversity both among the South African society and in terms of settlement patterns. Besides OpenStreetMap (OSM) as its main data source, this indicator uses a census and a travel survey to create a synthetic population of the study area. Accessibilities are computed based on people's daily activity chains. The second approach, an econometric accessibility indicator, relies exclusively on OSM and computes the accessibility of a given location as the weighted sum over the utilities of all opportunities reachable from that location including the costs of overcoming the distance. Neither a synthetic population nor travel information is used. It is found that the econometric indicator, although associated with much lower input data requirements, yields the same quality of insights regarding the identification of areas with low levels of accessibility. It also possesses advantages in terms of interpretability and policy sensitivity. In particular, its exclusive reliance on standardized and freely available input data and its easy portability are a novelty that can support the more widespread application of accessibility measures

On-the-fly memory compression for multibody algorithms.

Memory and bandwidth demands challenge developers of particle-based codes that have to scale on new architectures, as the growth of concurrency outperforms improvements in memory access facilities, as the memory per core tends to stagnate, and as communication networks cannot increase bandwidth arbitrary. We propose to analyse each particle of such a code to find out whether a hierarchical data representation storing data with reduced precision caps the memory demands without exceeding given error bounds. For admissible candidates, we perform this compression and thus reduce the pressure on the memory subsystem, lower the total memory footprint and reduce the data to be exchanged via MPI. Notably, our analysis and transformation changes the data compression dynamically, i.e. the choice of data format follows the solution characteristics, and it does not require us to alter the core simulation code

Performance of the BLAS-1 and other mathematical kernels on the SGI/Cray Origin 2000 processor

The purpose of this paper is to explore issues related to the computation and communication performance of the Basic Linear Algebra Subroutines (BLAS-1) and related kernels on the SGI/Cray Origin 2000 parallel computer. Experiments are performed both on vendor-supplied mathematical library routines as well as hand-coded loops and array syntax. The goal of this study is to get a better understanding of performance issues pertaining to the Origin 2000 architecture

Inclusion body hepatitis associated with an outbreak of fowl adenovirus type 2 and type 8b in broiler flocks in South Africa

Inclusion body hepatitis is an acute disease of chickens ascribed to viruses of the genus Aviadenovirus and referred to as fowl adenovirus (FAdV). There are 12 FAdV types (FAdV1 to FAdV8a and FAdV8b to FAdV11), classified into five species based on their genotype (designated FAdVA to FAdVE). A total of 218 000 chickens, 2–29 days of age, were affected over a 1-year period, all testing positive by microscopy, virus isolation and confirmation with polymerase chain reaction (PCR). Affected birds were depressed, lost body weight, were weak and had watery droppings. Pathological changes observed during necropsy indicated consistent changes in the liver, characterised by hepatomegaly, cholestasis and hepatitis. Lesions were also discernible in the spleen, kidney and gizzard wall and were characterised by splenomegaly, pinpoint haemorrhages, nephritis with haemorrhage,visceral gout and serosal ecchymosis of the gizzard wall. Histopathological lesions were most consistently observed in the liver but could also be seen in renal and splenic tissue. Virus isolation was achieved in embryonated eggs and most embryos revealed multifocal to diffuse hepatic necrosis, with a mixed cellular infiltrate of macrophages and heterophils (necro-granulomas), even in the absence of macroscopic pathology. Virus isolation results were verified by histopathology and PCR on embryonic material and further characterised by nucleotide sequence analysis. Two infectious bursal disease virus isolates were also made from the Klerksdorp flock. Nucleotide sequence analysis of the L1 hexon loop of all the FAdVisolates indicated homology (99%) with prototype strains P7-A for FAdV-2, as well as for FAdV-8b

Medical students as research participants: Student experiences, questionnaire response rates and preferred modes

Background. Research projects frequently include students, a potentially vulnerable population, as participants. Objectives. To determine University of the Free State (UFS) medical students’ experiences as research participants. Response rates to and preferences for hard copy and electronic questionnaires were also investigated. Methods. All 804 UFS undergraduate medical students in 2020 were approached to participate in this cross-sectional survey. Fourth- and fifth-year students and one-half of the third-year class were approached in person to complete anonymous hard copy questionnaires in a class setting. First- and second-year students and the other half of the third-year class were contacted electronically to complete anonymous electronic questionnaires. Results. Response rates to hard copy questionnaires were at least ~45% of the entire year group (and >70% of those to whom the questionnaire was distributed in class) compared with approximately a third of those contacted electronically. Students who responded to electronic questionnaires preferred electronic completion, whereas those who responded to hard copy questionnaires preferred the hard copy format, except fifth-year students. The majority of students (except those in their first year) had previously been approached to participate in research projects. Between a fifth and a third of all year groups indicated that they had refused participation at least once. More than a third of fifth-year students experienced insufficient time to decide on participation. Up to a quarter of third- to fifth-year groups had felt pressurised to participate. Conclusion. Hard copy questionnaires in class, the preferred data collection method for many students, produced better response rates but placed potential pressure on students to participate

Results on the effect of orderings on SSOR and ILU preconditionings

It is known that for SSOR and ILU preconditionings for solving systems of linear equations, orderings can have an enormous impact on robustness, convergence rate and parallelism. Unfortunately, it has been observed that there is an inverse relation between the convergence rate and the parallelism of typical orderings used in practice. This paper presents some numerical experiments with simple matrices to illustrate this behavior as well as a new theoretical result which sheds some light on this phenomenon and also gives an upper bound on the convergence rate of a number of preconditioners in popular use