Stably free modules of ‘big rank’ over polynomial rings are free

AbstractIt is well known that if R=A [X1,…,Xn], where A is a commutative Noetherian ring, then any stably free R-module P with rank P>dim A, is free. In this note we show that if A is an arbitrary commutative ring and rank P>dimA[X1,…,Xn]−n, then P is free

Exploring the Role of Environmental Quality and Time Perspective in the Academic Performance of Grade 12 Learners

The aim of this study was to determine to what extent environmental quality and time perspective can account for the variance in the academic performance of Grade 12 learners. Time perspective was assessed utilising the Zimbardo Time Perspective Inventory (ZTPI). Environmental quality was measured by means of a self-compiled questionnaire. A total of 413 Grade 12 learners from four English mediumschools in the Mangaung area of the Free State Province in South Africa were involved in the study. It was found that time perspective together with environmental quality accounts for approximately 14% of the variance found in the academic performance of Grade 12 learners. Although statistically significant relationships were found between time perspective and academic performance, these relationships were concluded to be of little practical importance. The academic performance of Grade 12 learners is of great importance as the results obtained from their final examinations are generally viewed as primary selection criteria for access to higher education institutions (Swartz, 1998; Uys, 1993; Huysamen, 2001). Various cognitive, personal and environmental factors have been found to influence learners’ academic performance (Moller, 1995; Louw, Van Ede & Louw, 1998; Malefo, 2000). Only a limited number of researchers have investigated the influence of environmental quality as well as time perspective on academic performance within the South African context. It is the aim of this study to explore the concepts of environmental quality and time perspective and their role in the academic performance of Grade 12 learners

Autologous whole blood clot and negative-pressure wound therapy in South Africa: A comparison of the cost and social considerations

Background. Advanced wound treatment modalities enhance healing of hard-to-heal wounds, decrease the risk of amputations, and improve the quality of life of patients. Modalities have different rates of efficacy and incur different social and financial costs to the individual and the healthcare system. Two such modalities, the autologous whole blood clot (WBC) and negative-pressure wound therapy (NPWT), were compared in the South African (SA) context. The comparison was conducted on hard-to-heal wounds, with a specific focus on diabetic foot ulcers (DFUs). Objectives. To compare the social considerations and financial costs of using autologous WBC v. NPWT in the treatment of DFUs in SA. Methods. Data were obtained based on current supply costs from SA suppliers for the two modalities, the standard of care for both modalities, the number of applications required for each, and social considerations provided by SA wound management clinicians. Wound healing rates were obtained from the published literature. This information was used to calculate costs of two scenarios (scenario 1: low exudate v. scenario 2: high exudate), which were compared over two treatment durations (4 and 12 weeks) for each treatment modality. Calculations included weekly cost of supplies, total cost saved by a patient with a DFU managed with either of the wound therapies, and the difference in total cost saved between the two modalities. Key social considerations were assessed qualitatively from discussions with SA clinicians experienced in both autologous WBC and NPWT, and from published research. Results. The cost of supplies per week was ZAR3 250 for autologous WBC and ZAR4 804 for NPWT in scenario 1, and ZAR3 332 and ZAR6 612 in scenario 2. With healing rates over 4 weeks’ treatment duration of 19% for autologous WBC and 10% for NPWT, autologous WBC saved ZAR17 719.93, or 9% more than using NPWT, in scenario 1 and ZAR18 381.47, or 10% more, in scenario 2. At 12 weeks’ treatment duration, healing rates for autologous WBC and NPWT were 75% and 43%, respectively. In scenario 1, results indicated a 43% cost difference between the two modalities. Autologous WBC had a total cost saving of ZAR61 874.40 compared with NPWT over a period of 12 weeks. In scenario 2, results indicated a 46% cost difference between the two modalities. Autologous WBC had a total cost saving of ZAR70 454.68 compared with NPWT over a period of 12 weeks. One of the identified social considerations is that NPWT needs a reliable supply of electricity to recharge the pump, while autologous WBC does not. Conclusion. Both modalities are safe and effective in treating hard-to-heal wounds of the lower extremities. Autologous WBC consistently demonstrated better outcomes than NPWT in terms of both healing rate and cost-effectiveness, as well as having some advantages in terms of social considerations in SA

Evaluating a financial service opportunity via judgemental modelling

The financial services market is currently undergoing tremendous change, due to the twin influences of developments in the field of Electronic Data Interchange (EDI) and changes in the legislation determining how banks will be allowed to operate after 1992. Describes research whose objective was to evaluate the viability of introducing a new service to handle cross-border payments, undertaken for a large multinational bank, and focused on respondents from a variety of firms within the European Community. Uses a combination of a PC-based judgemental modelling package and in-depth interviews to develop a clear understanding of the needs of both the originators′ and the vendors′ requirements. Although based on a relatively small sample, the detailed findings permit development of an effective approach to segmenting the market for the particular service

Serum prostate-specific antigen as surrogate for the Histological diagnosis of Prostate cancer

Introduction. To determine whether there is a cut-off value of serum prostate-specific antigen (PSA) which can be used confidently to make the diagnosis of prostate cancer, thereby obviating the need for biopsy.Patients and methods. During the period October 1991 to March 1998 the Department of Chemical Pathology at Tygerberg Hospital performed a total of 6 733 serum PSA assays on 3960 patients. The histopathological and clinical diagnoses of these patients were obtained from records in the departments of Anatomical Pathology, Urological Oncology and Radiation Oncology. The serum PSA levels were correlated with the histopathology reports, using different PSA cut-off values ranging from 5 to 500 ng/ ml, to calculate the sensitivity, specificity, and positive and negative predictive values of each cut-off value of PSA in predicting the presence of prostate cancer.Results. In total, 3 837 (57%) of the 6 733 serum PSA assays were ≤ 4 ng/ ml, 1 045 (15.5%) of the assays were ≥50 ng/ ml, and 798 (11.9%) were~ 100 ng/ ml. Of the total of 3 960 individual patients, 531 (13.4%) had a serum PSA ≥50 ng/ ml and 423 (10.7%) had a PSA ≥ 100 ng/ ml. A serum PSA of ≥ 30 ng/ml had a positive predictive value (PPV) of 90% at a specificity of 87% and sensitivity of 78%, while a PSA ≥ 60 ng/ ml had a PPV of 98% at a specificity of 98% and sensitivity of 65% for the presence of prostate cancer. The PPV reached 99% at a PSA ≥ 100 ng/ ml and 100% at a PSA ≥ 500 ng/ ml, with a specificity of 99% and 100%, but sensitivity of only 53% and 19%, respectively.Conclusions. A serum PSA ≥ 60 ng/ ml has a PPV of 98% for the presence of adenocarcinoma of the prostate, and may be used as a surrogate for histological diagnosis where facilities for obtaining prostatic biopsies are not readily available, thus decreasing costs and patient morbidity

Monitoring compliance of CITES lion bone exports from South Africa

From 2008 to 2018, South Africa permitted the export of captive-bred African lion (Panthera leo) skeletons to Southeast Asia under CITES Appendix II. Legal exports rose from approximately 50 individuals in 2008 to a maximum of 1,771 skeletons in 2016, and has led to ongoing concerns over possible laundering of non-lion, multiple-source and wild-sourced bones. South Africa is required under its obligations to CITES to employ mechanisms for monitoring and reporting trade, and to limit the potential for illegal trade and laundering of lion and other large felid bones. Monitoring tools for legal trade are critical to compliance with CITES. Here we evaluate the CITES-compliance procedure implemented by South Africa for export of lion bones and identify six essential general points for consideration in the implementation of animal export quota compliance protocols. We provide specific insight into the South African lion bone export monitoring system through: i) outlining the protocols followed; ii) assessing the utility of cranial morphology to identify species; iii) evaluating skeleton consignment weight as a monitoring tool; and iv) presenting molecular (DNA) species assignment and pairwise-comparative sample matching of individuals. We describe irregularities and illicit behaviour detected in the 2017 and 2018 lion bone quotas. Notably, we report that the compliance procedure successfully identified and prevented the attempted laundering of a tiger (P. tigris) skeleton in 2018. We emphasise the utility of mixed-method protocols for the monitoring of compliance in CITES Appendix II export quota systems

Early diagnosis of prostate cancer in the Western Cape

Background. Early stage prostate cancer does not cause symptoms, and even metastatic disease may exist for years without causing symptoms or signs. Whereas early stage prostate cancer can be cured with radical prostatectomy or radiotherapy, the prognosis of patients with locally advanced or metastatic cancer is significantly poorer.Objectives. ln view of the high incidence of advanced and therefore incurable prostate cancer seen at the oncology clinic of the Department of Urology, Tygerberg Hospital, we started a prostate clinic with the aim of detecting early stage prostate cancer which is potentially curable. A secondary objective was to investigate the question whether there is a higher incidence of prostate cancer among black African men.Patients and methods. Men aged 50 - 70 years were invited by means of media communications (newspaper and radio) to attend our prostate clinic for a free physical examination, including a digital rectal examination (DRE) and serum prostate specific antigen (PSA) assay. If the DRE was clinically suspicious of malignancy and/ or the serum PSA was > 4 ng/ ml, the patient was appropriately counselled and referred for transrectal ultrasound (TRUS)-guided sextant prostate biopsy.Results. In the period June 1997- September 1999 a total of 1056 men attended the prostate clinic. Biopsies were indicated in 160 cases, and were obtained in 114 (71.3%, i.e. 10.8% of the entire cohort). Prostate cancer was detected on first biopsy in 3.5% of the entire group of men (in 35.9% of those with a clinically abnormal DRE, in 41.3% of those with a serum PSA > 4 ng/ ml and in 88.6% of those with an abnormal DRE and serum PSA > 4 ng/ ml. In the 37 men with prostate cancer, the clinical tumour stage was T1 - 2 in 83.8% and T3- 4 in 16.2%. ln the group of patients with clinical stage T1 - 2 tumours, the treatment was watchful waiting in 62.5% of cases, radiotherapy in 20.8% and radical prostatectomy in 16.7%. Analysis of the data according to race showed that in the group of 47 black men there was a higher percentage of clinically abnormal DRE, PSA > 4 .0 ng/ ml and biopsies showing malignancy, and a higher overall prostate cancer detection rate (8.5%).Conclusions. Our prostate cancer detection rate of 3.5% is slightly lower than that reported in larger studies (4.7%), which may be due to the fact that prostate biopsy was performed in only 71% of those who had an indication for biopsy. ln the men diagnosed with clinically localised prostate cancer, potentially curative treatment was given in only 37.5% of cases. This compares unfavourably with the historical cohort of men seen at our oncology clinic, where 53% received potentially curative treatment, and a large European study where potentially curative treatment was given in 89% of cases. Our finding that black men had a higher percentage of clinically abnormal DRE, PSA > 4.0 ng/ ml and biopsies showing malignancy and a higher overall detection rate of prostate cancer should be interpreted with caution, since black men comprised only 4.5% of our overall study cohort.

Collaboration Towards a More Inclusive Society: The Case of South African ICT4D Researchers

In this study, research collaboration in the context of South African Information and Communication for Development (ICT4D) researchers was investigated using a mixed methods approach. South Africa, a country with stark development challenges and on the other hand a well-established ICT infrastructure, provides an appropriate context for ICT4D research. Firstly, a quantitative analysis of South African research collaboration between 2003 and 2016 was conducted to determine the existing research collaboration patterns of South African ICT4D researchers. This is based on the publications in three top ICT4D journals namely the Electronic Journal of Information Systems in Developing Countries (EJISDC), Information Technologies & International Development (ITID), and Information Technology for Development (ITD). The results show that most co-authored papers were intra-institutional collaborations, with limited inter-institutional collaboration between South African authors or between South African and other African authors. Secondly, interviews were conducted with South African researchers who emerged as inter- and intra-institutional collaborators to gain insight into the technology, drivers and barriers affecting South African research collaboration. We report our findings and discuss the implications for employing research collaboration as a mechanism for addressing inequality and supporting inclusion.School of Computin

Photosensitivity in South Africa. 1. A comparative study of Asaemia axillaris (Thunb.) Harv. Ex Jackson and Lasiospermum bipinnatum (Thunb.) Druce poisoning in sheep

Experimental evidence is presented to confirm field observations that Asaemia axillaris (Thunb.) Harv. ex Jackson and Lasiospermum bipinnatum (Thunb.) Druce cause ovine hepatogenous photosensitization. The two plants have fairly distinct distributions. While Lasiospermum is most prevalent in theeastern Karoo, Asaemia is commonest in the west and, except perhaps in the southern central Karoo,they seldom occur together. The locality of an outbreak should therefore be taken into account when making a diagnosis. Peripheral fatty changes and midzonal necrosis of liver lobules were seen in both Asaemia and Lasiospermum poisoning. Asaemia poisoning could, however, be distinguished from Lasiospermum poisoning by the presence of centrilobular fatty degeneration and the absence of haemorrhages and bile pigmentation. Although it may be difficult to distinguish between the two types of plant poisoning they are easily differentiated from geeldikkop (a major photosensitizing disease of the Karoo), which lacks a zonal pattern of hepatocytic degeneration and necrosis. Moreover, the crystalloid material characteristic of geeldikkop is not encountered in Asaemia or Lasiospermum poisoning.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

A highly fatal tremorgenic mycotoxicosis of cattle caused by Aspergillus clavatus

During February 1975, a tremorgenic neurotoxicosis decimated a herd of cattle in the northern Transvaal. This hitherto unidentified disease was characterized by hypersensitivity, incoordination, a peculiar stiff-legged gait of the hind legs, severe generalized tremors of the skeletal muscles, progressive paresis, paralysis and constipation. The most notable gross pathological lesions were degenerative and necrotic changes in certain skeletal muscles, haemorrhages on the serosal surfaces, especially on the dorsal aspect of the rumen, and gastro-intestinal stasis. Microscopical examination of the central nervous system revealed cytopathological changes consisting of degeneration and necrosis of the large motor cells in the ventral horns of the spinal cord and bigger neurones in numerous nuclei of the medulla oblongata, midbrain and thalamus. By feeding the suspect ration and its component parts to cattle and sheep, it was possible to identify mouldy sorghum beer residue as the toxic component in the ration. A. clavatus. the dominant fungus on the toxic residue, was readily isolated in pure culture. The entire syndrome was then reproduced in a yearling Friesland steer dosed with pure cultures of the A. clavatus isolate grown on autoclaved non-toxic sorghum beer residue. The toxic principle is not known, but it does not appear to be patulin, tryptoquivalone, tryptoquivaline, or any other known tremorgen.The articles have been scanned in colour with a HP scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentyation PDF-Format