Outsmarting COVID-19 through rapid 3D printing and flipped learning in fixed prosthodontics

No Abstrac

Permian trace fossils attributed to tetrapods (Tierberg Formation, Karoo Basin, South Africa)

The discovery of a paving slab with a number of prints suggestive of footprints of tetrapods led to a reinvestigation of a trace fossil, known from three localities, of which only two photographs had been published, each with only four prints. The slab was traced to a previously unrecorded site, De Puts, near Calvinia, located in the Tierberg Formation of the Ecca Group of the Karoo Supergroup. The prints from all the sites are referred to Broomichnium permianum Kuhn 1958, of which Quadrispinichna parvia of Anderson 1974 is a synonym.Palaeo-Anthropology Scientific Trust; French Embassy in South Africa; Co-operation and Cultural Servic

Palaeozoic insects of southern Africa: a review

Although a substantial number of Triassic insect fossils have been discovered in southern Africa, relatively few insect fossils are known from the Permian deposits of this region. Fossil insects from the Permian period elsewhere, including the extensive entomological fauna from Eastern Europe (including Russia), Brazil and Australia is well-documented. The Irati Formation in the Parana Basin of Brazil, the temporal and lithological correlate of the Permian Whitehill Formation of South Africa, has yielded fossil insects belonging to Homoptera, N europtera, Coleoptera and Mecoptera. Fossil insects from the Whitehill Formation are usually poorly preserved and only seven specimens are mentioned in the literature. An overview is given of the more recent discoveries of Permian fossil insects in South Africa. This includes the discovery of the oldest beetle in Africa, the oldest longhorned grasshopper in the Southern Hemisphere and a survey of the Permian insects from the Beaufort Group of Natal. Reasons for the paucity of Permian insects are briefly discussed.Palaeo-Anthropology Scientific Trust; French Embassy in South Africa; Co-operation and Cultural Servic

The role of the gamma function shape parameter in determining differences between condensation rates in bin and bulk microphysics schemes

The condensation and evaporation rates predicted by bin and bulk microphysics schemes in the same model framework are compared in a statistical way using simulations of non-precipitating shallow cumulus clouds. Despite other fundamental disparities between the bin and bulk condensation parameterizations, the differences in condensation rates are predominantly explained by accounting for the width of the cloud droplet size distributions simulated by the bin scheme. While the bin scheme does not always predict a cloud droplet size distribution that is well represented by a gamma distribution function (which is assumed by bulk schemes), this fact appears to be of secondary importance for explaining why the two schemes predict different condensation and evaporation rates. The width of the cloud droplet size is not well constrained by observations, and thus it is difficult to know how to appropriately specify it in bulk microphysics schemes. However, this study shows that enhancing our observations of this width and its behavior in clouds is important for accurately predicting condensation and evaporation rates

Developing a Patient-Specific Maxillary Implant Using Additive Manufacturing and Design

Published Conference ProceedingsMaxillectomy is the surgical removal or resection of the maxilla or upper jaw bone. A total or partial maxillectomy can be performed depending on how far the tumour has spread. This paper will discuss a patient diagnosed with an aggressive tumour in half of the top jaw who had to undergo an operation to remove the hemi-maxilla and orbital floor. Due to the extent and complexity of the defect, it was decided to manufacture an anatomical model of the hard tissues for planning a possible laser-sintered titanium implant using Additive Manufacturing (AM). The CRPM had only two weeks to design and manufacture the titanium implant, due to the severity of the tumour. The anatomical model was sent to the surgeon to cut the nylon model where the bone resection was planned. Furthermore, the prosthodontist made a wax model of the planned titanium frame that was reverse- engineered and used as reference geometry in the design software.Materialise® design suite was used to design the patient-specific maxilla and cutting jig. The EOS M280 Direct Metal Laser Sintering (DMLS) system was instrumental in achieving the direct manufacturing of the bio-compatible titanium implant. The EOS P385 system was used to manufacture the pre-operation planning model as well as the cutting jig.The process chain followed to complete this case study will be discussed showing how this intervention improved the quality of life of a SA patient. Furthermore, the proposed paper and presentation will discuss the post-operation review of the patient showing the impact AM had in accelerating patient-specific implant manufacturing. The authors seek to claim a progressed level of maturity in the proposed manufacturing value chain. The claim is based on the successful completion of the analysis and synthesis of the problem , the validated proof-of-concept of the manufacturing process and the in-vivo implementation of the final product

COVID-19 vaccines – less obfuscation, more transparency and action

Letter by Venter et al. on editorial  by Schoub (Dial down the rhetoric over COVID-19 vaccines. S Afr Med J 2021;111(6):522-523. https://doi.org/10.7196/SAMJ.2021.v111i6.15740)

Periodic variability of the mainline hydroxyl masers in G9.62+0.20E

We present the results of a monitoring campaign using the KAT-7 and HartRAO 26m telescopes, of hydroxyl, methanol and water vapour masers associated with the high-mass star forming region G9.62+0.20E. Periodic flaring of the main line hydroxyl masers were found, similar to that seen in the 6.7 and 12.2 GHz methanol masers. The 1667 MHz flares are characterized by a rapid decrease in flux density which is coincident with the start of the 12.2 GHz methanol maser flare. The decrease in the OH maser flux density is followed by a slow increase till a maximum is reached after which the maser decays to its pre-flare level. A possible interpretation of the rapid decrease in the maser flux density is presented. Considering the projected separation between the periodic methanol and OH masers, we conclude that the periodic 12.2 methanol masing region is located about 1600 AU deeper into the molecular envelope compared to the location of the periodic OH masers. A single water maser flare was also detected which seems not to be associated with the same event that gives rise to the periodic methanol and OH maser flares.Comment: 8 pages, 11 figure

Retrospective outcome analysis of urethroplasties performed for various etiologies in a single South African centre

This is the author’s version of a work that was accepted for publication of the article: African Journal of Urology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in African Journal of Urology, VOL 18, Issue 3, 2012, DOI: 10.1016/j.afju.2012.03.001.Objectives: To compare the results of anastomotic versus augmentation urethroplasty (buccal mucosa graft (BMG) onlay), as well as dorsal versus ventral BMG techniques. Methods: A retrospective audit of 69 patients who underwent urethroplasty at Eersteriver Hospital in Cape Town, South Africa between October 2004 and July 2011 was undertaken. Analysis included stricture etiology, location and length, type of surgery performed as well as complication rates over the follow-up period. Results: The predominant stricture etiologies were traumatic and infective causes (55%), with a mean stricture length of 3 cm (0.5–15 cm). Forty two patients had bulbar urethra strictures (61%), with 8 (11%) located in the posterior, and penile & bulbar regions, respectively. The remaining strictures were located in the penile urethra (16%). Surgery performed included bulbar (12) and membranous anastomotic (8) urethroplasty, ventral (13) and dorsal (22) buccal mucosa onlay grafts (BMG), and 2-stage urethroplasty (14). Overall stricture recurrence was seen in 9 patients (13%), including 1 patient (8%) of the anterior end-to-end anastomotic group compared to 2 patients (6%) of the onlay BMG group (p = 0.77). The re-stricture rates were 5% and 8% in the dorsal (1/22) and ventral BMG onlay groups (1/13), respectively (p = 0.72)

Safeguarding maternal and child health in South Africa by starting the Child Support Grant before birth: Design lessons from pregnancy support programmes in 27 countries

Background: Deprivation during pregnancy and the neonatal period increases maternal morbidity, reduces birth weight and impairs child development, with lifelong consequences. Many poor countries provide grants to mitigate the impact of poverty during pregnancy. South Africa (SA) offers a post-delivery Child Support Grant (CSG), which could encompass support during pregnancy, informed by lessons learnt from similar grants. Objectives: To review design and operational features of pregnancy support programmes, highlighting features that promote their effectiveness and efficiency, and implications thereof for SA. Methods: Systematic review of programmes providing cash or other support during pregnancy in low- and middle-income countries. Results: Thirty-two programmes were identified, across 27 countries. Programmes aimed to influence health service utilisation, but also longer-term health and social outcomes. Half included conditionalities around service utilisation. Multifaceted support, such as cash and vouchers, necessitated complex parallel administrative procedures. Five included design features to diminish perverse incentives. These and other complex features were often abandoned over time. Operational barriers and administrative costs were lowest in programmes with simplified procedures and that were integrated within child support. Conclusions: Pregnancy support in SA would be feasible and effective if integrated within existing social support programmes and operationally simple. This requires uncomplicated enrolment procedures (e.g. an antenatal card), cash-only support, and few or no conditionalities. To overcome political barriers to implementation, the design might initially need to include features that discourage pregnancy incentives. Support could incentivise service utilisation, without difficult-to-measure conditionalities. Beginning the CSG in pregnancy would be operationally simple and could substantially transform maternal and child health