H.G. Stoker as student - die wysgerige denkklimaat en akademiese wisselwerking met Scheler en Buytendijk

This article represents an indispensable part of the total corpus of this issue. It contains a transcription of the letters of H.G. Stoker to F.J.J. Buytendijk, annotated by Arnold Beijk and further illuminated and commented on by Theo van der Merwe. This kind of archival material is of immense value in developing a comprehensive vision and overview of H.G. Stoker’s work not only for the more casual reader, but more particularly for the serious scholar who can find solid academic support in these documents for assumptions made about Stoker's work. Stoker’s creative and illuminating personal style of thinking and writing is well demonstrated here. The letters reveal very strikingly the course o f the academic interaction between Stoker and Buytendijk about his study on conscience which he was conducting under the guidance of Max Scheler. The material also provides fascinating incidental material about Stoker's vision of the country and its universities, more particularly the University of Potchefstroom, at the time. His perspective on his own academic ideals comes out well and ties in with considerations drawn from the European milieu

Manufacturing of custom-made medical implants for cranio / maxillofacial and orthopaedic surgery - an overview of the current state of the industry

Published ArticleExtensive work has been done in the area of manufacturing implants for medical purposes, and more recently the development of customised implants. Areas of application include cranio/maxillo-facial implants, dental drill guides, hip, knee and shoulder replacements, as well as different implants for the spine. Due to their high prevalence and complex anatomical geometry the purpose of this study is to investigate the current state of the industry regarding customised medical implants for cranio/maxillofacial and orthopaedic surgery. Implant customisation has far-reaching benefits, and a collective approach to solving current difficulties will require an in-depth study of successes already achieved. Several issues in this regard are examined, including what defines customisation, regulatory issues that govern customisation and design constraints, trends in different areas of application, suitable materials, and finally which manufacturing techniques are being employed, with a focus on the use of Layer Manufacturing technologies and their role in custom-made medical implants

Hookah pipe smoking among health sciences students

BACKGROUND: Hookah pipe smoking is a social practice and has gained popularity, especially among South African youth. The extent of this practice among health sciences students, and their knowledge regarding the health risks, are unknown. This is important, as these students will become future health professionals possibly influencing the practice of individuals and communities. OBJECTIVE: To explore the knowledge, attitudes and practices of hookah pipe smoking among students at the Faculty of Health Sciences, University of Cape Town. METHODS. A cross-sectional study was conducted among undergraduate and postgraduate students. A self-administered questionnaire was distributed as a hard copy and online survey. RESULTS: Of 228 participants, 66% had smoked a hookah pipe before, with 18% still smoking. Most began smoking in high school, with 25% initiating at university. Of the current smokers, 65% smoked occasionally socially, commonly at friends' houses for 30 - 60 min/session. A further 11% smoked cigarettes concurrently and 30% added other substances, mainly cannabis, to pipes. Most current hookah smokers had no interest in quitting (84%). Only 30% of participants had prior health information about hookah pipe smoking. Most knew that it was harmful (91%), with many not knowing why. A total of 80% of participants perceived that the practice was socially acceptable and 84% would recommend it to others.CONCLUSION; The poor knowledge about the dangers of hookah pipe smoking and the extent of its practice among health sciences students is alarming. These findings highlight the need for school and university health promotion campaigns, and for better regulation of hookah pipe smoking

Drivers of inter-annual variability in Net Ecosystem Exchange in a semi-arid savanna ecosystem, South Africa

Inter-annual variability in primary production and ecosystem respiration was explored using eddy-covariance data at a semi-arid savanna site in the Kruger Park, South Africa. New methods of extrapolating night-time respiration to the entire day and filling gaps in eddy-covariance data in semi-arid systems were developed. Net ecosystem exchange (NEE) in these systems occurs as pulses associated with rainfall events, a pattern not well-represented in current standard gap-filling procedures developed primarily for temperate flux sites. They furthermore do not take into account the decrease in respiration at high soil temperatures. An artificial neural network (ANN) model incorporating these features predicted measured fluxes accurately (MAE 0.42 gC/m<sup>2</sup>/day), and was able to represent the seasonal patterns of photosynthesis and respiration at the site. The amount of green leaf area (indexed using satellite-derived estimates of fractional interception of photosynthetically active radiation <i>f</i><sub>APAR</sub>), and the timing and magnitude of rainfall events, were the two most important predictors used in the ANN model. These drivers were also identified by multiple linear regressions (MLR), with strong interactive effects. The annual integral of the filled NEE data was found to range from −138 to +155 g C/m<sup>2</sup>/y over the 5 year eddy covariance measurement period. When applied to a 25 year time series of meteorological data, the ANN model predicts an annual mean NEE of 75(±105) g C/m<sup>2</sup>/y. The main correlates of this inter-annual variability were found to be variation in the amount of absorbed photosynthetically active radiation (APAR), length of the growing season, and number of days in the year when moisture was available in the soil

A simulation study to compare reference and other priors in the case of a standard univariate Student t-distribution

In this paper, reference and probability-matching priors are derived for the univariate Student t-distribution. These priors generally lead to procedures with properties frequentists can relate to while still retaining Bayes validity. The priors are tested by performing simulation studies. The focus is on the relative mean squared error from the posterior median and on the frequentist coverage of the 95% credibility intervals for a sample of size n = 30. Average interval lengths of the credibility intervals as well as the modes of the interval lengths based on 2 000 simulations are also considered. The performance of the priors is also tested on real data, namely daily logarithmic returns of IBM stocks

Secondary polycythaemia with elevated carbon monoxide levels due to hookah pipe smoking: A public health concern.

Hookah pipe (HP) smoking is perceived as a harmless activity, enjoyed by young adults and high school-going children. Awareness of the health impact of recreational habits, and their intersection with new social norms in the COVID-era, requires critical review. We describe a case series of young HP smokers presenting with secondary polycythaemia with significant clinical sequelae necessitating extensive work-up. HP smoking may lead to acute and chronic carbon monoxide intoxication, with resultant secondary polycythaemia and complications including provoked thrombosis

Sourcing the ore from the Drierivier copper smelting site in central Namibia, using lead isotope fingerprinting

Copper smelting residues from C. AD 1650 found at the Drierivier site near Rehoboth in central Namibia have 207Pb/206Pb isotope ratios that match a particular deposit at Swartmodder, but are markedly different from other known occurrences in the Rehoboth–Windhoek areas. For this reason, precise lead isotope determination is not necessary to source the ore, and raw peak height ratios obtained by inductively coupled plasma mass spectrometry are sufficient. This characteristic signature is present in all samples of malachite ore, slag, and copper prills collected on the site. Significantly, it is absent from a sample of local native copper, as well as from seven copper beads found elsewhere in central Namibia. This not only identifies the probable source of malachite ore but also provides a powerful tool for provenancing copper artefacts made at the Drierivier site, distinguishing them from those made elsewhere in the Namibian highlands

'We did everything we could'- A qualitative study exploring the acceptability of maternal-fetal surgery for spina bifida to parents

OBJECTIVE: To explore the concepts and strategies parents employ when considering maternal-fetal surgery (MFS) as an option for the management of spina bifida (SB) in their fetus, and how this determines the acceptability of the intervention. METHODS: A two-centre interview study enrolling parents whose fetuses with SB were eligible for MFS. To assess differences in acceptability, parents opting for MFS (n=24) were interviewed at three different moments in time: prior to the intervention, directly after the intervention and 3-6 months after birth. Parents opting for termination of pregnancy (n=5) were interviewed only once. Themes were identified and organised in line with the framework of acceptability. RESULTS: To parents opting for MFS, the intervention was perceived as an opportunity that needed to be taken. Feelings of parental responsibility drove them to do anything in their power to improve their future child's situation. Expectations seemed to be realistic yet were driven by hope for the best outcome. None expressed decisional regret at any stage, despite substantial impact and, at times, disappointing outcomes. For the small group of participants, who decided to opt for termination of pregnancy (TOP), MFS was not perceived as an intervention that substantially could improve the quality of their future child's life. CONCLUSION: Prospective parents opting for MFS were driven by their feelings of parental responsibility. They recognise the fetus as their future child and value information and care focusing on optimising the child's future health. In the small group of parents opting for TOP, MFS was felt to offer insufficient certainty of substantial improvement in quality of life and the perceived severe impact of SB drove their decision to end the pregnancy This article is protected by copyright. All rights reserved