Die Via Dolorosa

In die hartjie van Jerusalem, die heilige stad vir Jood, Mohammedaan en Christen staan daar ’n boog, die ,,Ecce Homoboog” genaamd, en 'n klein endjie daarvandaan, die Heilige Grafkerk

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

DNA amplified fingerprinting, a useful tool for determination of genetic origin and diversity analysis in Citrus

We used three short repetitive nucleotide sequences [(GTG)5, (TAC)5, and (GACA)4] either as radiolabeled probes for hybridization with restricted Citrus DNA or as single primers in polymerase chain reaction amplification experiments with total genomic DNA. We tested the ability of the sequences to discriminate between seedlings of zygotic or nuclear origin in the progeny of a Volkamer lemon #Citrus volkameriana# Ten. & Pasq.) tree. The genetic variability within two species [#Citrus sinensis# (L.) Osbeck (sweet oranges) and #Citrus reticulata# Blanco and relatives (mandarins)] was evaluated. DNA amplified figerprinting with single primers was the more successful technique for discriminating between nucellular and zygotic seedlings. Although we were not able to distinguish among 10 cultivars of #C. sinensis#, all 10 #C. reticulata# cultivars tested were distinguishable. However, it still is difficult to identify the putative parents of a hybrid plant when the two parental genomes are closely related. (Résumé d'auteur

Calculation aspects of the European rebalanced basket option using Monte Carlo methods : valuation

CITATION: Van der Merwe, C. J. & Conradie, W. J. 2012. Calculation aspects of the European rebalanced basket option using Monte Carlo methods : valuation. Orion, 28(1):1-18, doi:10.5784/28-1-104.The original publication is available at http://orion.journals.ac.zaExtra premiums can be charged to a client to guarantee a minimum payout of a contract on a portfolio that gets rebalanced on a regular basis back to fixed proportions. The valuation of this premium can be changed to that of the pricing of a European put option with underlying rebalanced portfolio. This article finds the most efficient estimators for the value of this path-dependant multi-asset put option using different Monte Carlo methods. With the help of a refined method, computing time of the value decreased significantly. Furthermore, Variance Reduction Techniques and Quasi-Monte Carlo methods delivered more accurate and faster converging estimates as well.http://orion.journals.ac.za/pub/article/view/104Publisher's versio

Bruker2nifti: Magnetic Resonance Images converter from Bruker ParaVision to Nifti format

In clinical and pre-clinical research involving medical images, the first step following a Magnetic Resonance Imaging dataset acquisition, usually entails the conversion of image data from the native scanner format to a format suitable for the intended analysis. The proprietary [Bruker ParaVision](https://www.bruker.com/products/mr/preclinical-mri/software/service-support.html) software currently does not provide the tools for conversion of the data to suitable and open formats for research, such as nifti [@cox2004sort], for which most of the available tools for medical image analysis are implemented. For this purpose we have designed and developed [bruker2nifti](https://github.com/SebastianoF/bruker2nifti), a pip-installable Python tool provided with a Graphical User Interface to convert from the native MRI Bruker format to the nifti format, without any intermediate step through the DICOM standard formats [@Mildenberger2002]. Bruker2nifti is intended to be a tool to access the data structure and to parse all parameter files of the Bruker ParaVision format into python dictionaries, to select the relevant information to fill the Nifti header and data volume. Lastly it is meant to be a starting point where to integrate possible future variations in Bruker hardware and ParaVision software future releases

Progressive familial heart block type I : clinical and pathological observations

CITATION: 1991: .Van der Merwe, P.-L. et al. 1991. Progressive familial heart block type I : clinical and pathological observations. South African Medical Journal, 80:34-38.The original publication is available at http://www.samj.org.zaProgressive familial heart block type I (PFHB-I) is an autosomal inherited disease. It was previously postulated that the disease is limited to the cardiac conduction tissue. The presentation of a patient with dilated cardiomyopathy focused on the possibility that this might be part of PFHB-I. This observation led to routine echocardiographic examination of patients with complete heart block, who belonged to PFHB-I families, and another 5 cases with signs of dilated cardiomyopathy were identified. This is the first time, to our knowledge, that the histological picture of PFHB-I has been described. From these case reports it is clear that in the presence of a dilated cardiomyopathy the prognosis in PFHB-I tends to be poor.Publisher’s versio

Islet neogenesis is stimulated by brief occlusion of the main pancreatic duct

Objective. Current models of islet neogenesis either cause substantial pancreatic damage or continuously stimulate the pancreas, making these models unsuitable for the study of early events that occur in the neogenic process. We aimed to develop a method where the initial events that culminate in increased pancreatic endocrine mass caube studied. Design and methods. Ten 12-week-old female Wistar rats were subjected to a midline laparotomy, the pancreas was isolated and the main pancreatic duct was occluded for 60 seconds. The pancreas was released and carefully relocated within the abdomen. Ten age-, strain- and sex-matched control rats were subjected to a sham operation. The animals were killed 56 days post .occlusion, and the pancreata excised and fiXed tor histological analysis. Body, pancreatic and hepatic weights were .noted at termination. and serum was taken for analysis. The endocrine-to-exocrine. ratio was calculated and the number of endocrine cells in eacn islet from the sectioned pancreata was counted. Results. Occlusion of the main pancreatic ductfor 60 seconds results in an increase in endocrine mass. by 80% 56 days post occlusion. This constitutes an increase in endocrine units (1 - 6 cellst and in small (7 - 30 cells), medium (31 - 60 cells) and large (> 60 cells) islets by 85%, 96%, 95% and 71% respectively. Conclusion. Brief occlusion of the main pancreatic duct results in anincrease in pancreatic endocrine. mass. An increase in endocrine units and small islets is indicative of islet neogenesis. Therefore, owing to the briefness of the stimulation; this model can therefore be used to study the iniUal events that occur during the neogenic process

Intra-operative pneumatic tourniquet – perceptions of use and complications in the orthopaedic community of South Africa

OBJECTIVES: To assess views on use, maintenance and side-effects of the pneumatic tourniquet in the South African orthopaedic community. METHODS: A census-type questionnaire study was conducted of all 475 orthopaedic surgeons registered with the Orthopaedic Association of South Africa during 1993/94. The chi-square test was used to determine statistical significance between different groups of respondents. RESULTS: Seventy-seven per cent of the questionnaires were returned. Ninety-nine per cent of respondents used a pneumatic tourniquet. Eighty-four per cent believed that the tourniquet may damage underlying tissue both as a result of applied pressure effects and ischaemic consequences. Fifty-four per cent of respondents personally checked the calibration of the pneumatic tourniquet, although 76% of respondents believe that the apparatus needs to be checked at least once per month. More respondents who did not check the tourniquet apparatus than respondents who did check it believe that applied pressure does not cause tissue damage (P < 0.001), that the operating room technician or hospital engineer should be responsible for checking equipment (P < 0.001), and that equipment did not need to be checked more than once every 6 months (P < 0.001). CONCLUSIONS: Although most orthopaedic surgeons are aware of the pneumatic tourniquet's side-effects, a minority appear to be unaware of the hazards of excessive applied pressure alone or excessive applied pressure caused by use of faulty equipment. It needs to be emphasised to these surgeons that regular checking of the pneumatic tourniquet apparatus is necessary in order to prevent postoperative complications ascribed to use of the tourniquet