The Emmaus narrative and contemporary Christian followership – An empirical case study

This article aims to explore a ‘lived discipleship’ by determining whether and how contemporary communities of faith could implement the norms and principles reflected in the Emmaus narrative of Luke 24:13–35 within a plausible epistemological framework that might facilitate a fresh understanding of Christian followership as discipleship. This was done through an empirical case study using two focus groups as co-researchers, in order to actively listen to their respective understandings of lived theology in their unique South African contexts. The two focus groups consisted of (1) a contemporary Christian grouping of Afrikaans-speaking, active churchgoers situated in Hazeldean, a suburb in Pretoria East, Tshwane, Gauteng and (2) a contemporary Christian grouping of African, active churchgoers situated in Ivory Park, a suburb in Tembisa, Ekurhuleni, Gauteng. This article concluded that Luke 24:13–35 nudged the co-researchers to re-evaluate their contemporary understanding of discipleship and moved them to additional and new perspectives in terms of practical expressions thereof that can be best described as ‘lived followership’. A shift from perceiving Jesus in terms of an ‘act to follow’ by gaining the correct knowledge, to following Jesus as ‘a performative act’, a shift from ‘theoretical knowledge’ to ‘heart knowledge’. Contribution: This article is a part of the Festschrift for Prof. Stephan Joubert. This article plays into similar creative interdisciplinary relationship as seen in the work of Prof. Joubert, by looking at the relationship between New Testament and Practical Theology in order to improve practices of faith that is rooted in a biblical understanding of Jesus

A multi-institutional quantitative survey of multi-leaf collimator accuracy using a digital picket fence test with sub-millimetre detection capabilities.

Medical Imaging and Clinical Oncology: Medical Physic

A synoptic decomposition of rainfall over the Cape south coast of South Africa

A synoptic climatology is derived for the Cape south coast region of South Africa by application of the self-organizing map (SOM) technique. The SOM is applied to average daily low-level circulation fields, as represented by sea-level pressure anomalies for the period 1979–2011. This coastal region receives rainfall all-year round with slight peaks during March–April and with more pronounced peaks during August and October–November. The synoptic forcing responsible for this annual multimodal rainfall distribution is identified, and the relative contribution of different synoptic types to the annual rainfall is quantified. Ridging high pressure systems contribute to 46 % of the annual rainfall, while tropical–temperate troughs contribute 28 %. Cut-off lows (COLs) co-occurring with ridging highs and tropical–temperate troughs are associated with 16 % of the annual rainfall total. The contribution of ridging high pressure systems decreases from south to north, whilst the opposite is true for tropical–temperate troughs. COLs, ridging high pressure systems and tropical– temperate troughs are associated with the March–April rainfall peak, while COLs are largely associated with the August rainfall peak. Ridging high pressure systems and to a lesser extent tropical–temperate troughs, are responsible for the October peak observed along the coast, while the November peak over the adjacent interior regions is associated with COLs that occur in combination with the tropical– temperate troughs during this month.Water Research Commission (Project K5/2257/1) and the Applied Centre for Climate and Earth System Studies (ACCESS) in South Africa.http://link.springer.com/journal/3822016-05-31hb201

Subseasonal deterministic prediction skill of low-level geopotential height affecting southern Africa

The NCEP CFSv2 and ECMWF hindcasts are used to explore the deterministic subseasonal predictability of the 850-hPa circulation of a large domain over the Atlantic and Indian Oceans that is relevant to the weather and climate of the southern African region. For NCEP CFSv2, 12 years of hindcasts, starting on 1 January 1999 and initialized daily for four ensemble members up to 31 December 2010 are verified against ERA-Interim reanalysis data. For ECMWF, 20 years of hindcasts (1995–2014), initialized once a month for all the months of the year are employed in a parallel analysis to investigate the predictability of the 850-hPa circulation. The ensemble mean for 7-day moving averages is used to assess the prediction skill for all the start dates in each month of the year, with a focus on the start dates in each month that are representative of the week-3 and week-4 hindcasts. The correlation between the anomaly patterns over the study domain shows skill over persistence up into the week-3 hindcasts for some months. The spatial distribution of the correlation between the anomaly patterns show skill over persistence to notably reduce over the domain by week 3. A prominent area where prediction skill survives the longest, occur over central South America and the adjacent Atlantic Ocean.NRFhttps://journals.ametsoc.org/view/journals/wefo/wefo-overview.xmldm2022Geography, Geoinformatics and Meteorolog

Tropical systems from the southwest Indian Ocean making landfall over the Limpopo River Basin, southern Africa : a historical perspective

The study provides perspective on the contribution of landfalling tropical systems (cyclones, depressions, storms and lows) from the southwest Indian Ocean (SWIO) towards rainfall over the eastern interior of southern Africa, over the period 1948-2008. Although these systems contribute to < 10% of the annual rainfall occurring over the region, their relative contribution to local and widespread heavy rainfall events is shown to be highly significant. About 50% of widespread heavy rainfall events over northeastern South Africa are caused by landfalling tropical systems. Fourier analysis performed on the time series of rainfall occurring over notheastern South Africa in association with these systems reveals the existence of a quasi-18-year cycle. The cycle coincides with the well-known quasi-18-year Dyer-Tyson cycle in rainfall over the summer rainfall region of South Africa. These results suggest that atmospheric and surface conditions leading to wet phases of the Dyer-Tyson cycle also favour the landfall and subsequent westward movement of tropical systems from the SWIO over southern Africa – and their eventual contribution to rainfall over northeastern South Africa and southern Zimbabwe.Water Research Commission, South Africa (WRC Project No. K5/1847).http://www3.interscience.wiley.com/journal/4735/hom

A short-range weather prediction system for South Africa based on a multi-model approach

The accurate prediction of rainfall events, in terms of their timing, location and rainfall depth, is important to a wide range of social and economic applications. At many operational weather prediction centres, as is also the case at the South African Weather Service, forecasters use deterministic model outputs as guidance to produce subjective probabilistic rainfall forecasts. The aim of this research was to determine the skill of a new objective multi-model, multi-institute probabilistic ensemble forecast system for South Africa. Such forecasts are obtained by combining the rainfall forecasts of 2 operational high-resolution regional atmospheric models in South Africa. The first model is the Unified Model (UM), which is operational at the South African Weather Service. The UM contributes 3 ensemble members, each with a different physics scheme, data assimilation techniques and horizontal resolution. The second model is the Conformal-Cubic Atmospheric Model (CCAM) which is operational at the Council for Scientific and Industrial Research, which in turn contributed 2 members to the ensemble system based on different horizontal resolutions. A single-model ensemble forecast, with each of the ensemble members having equal weights, was constructed for the UM and CCAM models, respectively. These UM and CCAM single-model ensemble predictions are then combined into a multi-model ensemble prediction, using simple un-weighted averaging. The probabilistic forecasts produced by the single-model system as well as the multi-model system have been tested against observed rainfall data over 3 austral summer 6-month periods from 2006/07 to 2008/09, using the Brier skill score, relative operating characteristics, and the reliability diagram. The forecast system was found to be more skilful than the persistence forecast. Moreover, the system outscores the forecast skill of the individual models.The South African Weather Service and the Water Research Commission, through Project K5/1646, funded the creation of the CCAM hindcast data used in this study.http://www.wrc.org.z

Serum Amyloid A Binds to Gibrin(ogen), Promoting Fibrin Amyloid Formation

Complex associations exist between inflammation and thrombosis, with the inflammatory state tending to promote coagulation. Fibrinogen, an acute phase protein, has been shown to interact with the amyloidogenic ß-amyloid protein of Alzheimer’s disease. However, little is known about the association between fibrinogen and serum amyloid A (SAA), a highly fibrillogenic protein that is one of the most dramatically changing acute phase reactants in the circulation. To study the role of SAA in coagulation and thrombosis, in vitro experiments were performed where purified human SAA, in concentrations resembling a modest acute phase response, was added to platelet-poor plasma (PPP) and whole blood (WB), as well as purified and fluorescently labelled fibrinogen. Results from thromboelastography (TEG) suggest that SAA causes atypical coagulation with a fibrin(ogen)-mediated increase in coagulation, but a decreased platelet/fibrin(ogen) interaction. In WB scanning electron microscopy analysis, SAA mediated red blood cell (RBC) agglutination, platelet activation and clumping, but not platelet spreading. Following clot formation in PPP, the presence of SAA increased amyloid formation of fibrin(ogen) as determined both with auto-fluorescence and with fluorogenic amyloid markers, under confocal microcopy. SAA also binds to fibrinogen, as determined with a fluorescent-labelled SAA antibody and correlative light electron microscopy (CLEM). The data presented here indicate that SAA can affect coagulation by inducing amyloid formation in fibrin(ogen), as well as by propelling platelets to a more prothrombotic state. The discovery of these multiple and complex effects of SAA on coagulation invite further mechanistic analyses

Projected changes in tropical cyclone climatology and landfall in the southwest Indian Ocean region under enhanced anthropogenic forcing

The conformal-cubic atmospheric model, a variable-resolution global model, is applied at high spatial resolution to perform simulations of present-day and future climate over southern Africa and over the Southwest Indian Ocean. The model is forced with the bias-corrected sea-surface temperatures and sea-ice of six coupled global climate models that contributed to Assessment Report 4 of the Intergovernmental Panel on Climate Change. All six simulations are for the period 1961–2100, under the A2 emission scenario. Projections for the latter part of the 21st century indicate a decrease in the occurrence of tropical cyclones over the Southwest Indian Ocean adjacent to southern Africa, as well as a northward shift in the preferred landfall position of these systems over the southern African subcontinent. A concurrent increase in January to March rainfall is projected for northern Mozambique and southern Tanzania, with decreases projected further south over semi-arid areas such as the Limpopo River Basin where these systems make an important contribution as main cause of widespread heavy rainfall. It is shown that the projected changes in tropical cyclone attributes and regional rainfall occur in relation to changes in larger scale atmospheric temperature, pressure and wind profiles of the southern African region and adjacent oceans.The Water Research Commission (WRC Project No. K5/1847) in South Africa, as well as the Agricultural Research Council and the Council for Scientific and Industrial Research, South Africa.http://link.springer.com/journal/382hb201

The bi-decadal rainfall cycle, Southern Annular Mode and tropical cyclones over the Limpopo River Basin, southern Africa

The association between bi-decadal rainfall variability over southern Africa and the rainfall contributed by tropical cyclonic systems from the Southwest Indian Ocean (SWIO) provides a potential means towards understanding decadal-scale variability over parts of the region. A multi-decadal period is considered, focusing on the anomalous tropospheric patterns that induced a particularly wet 8-year long sub-period over the Limpopo River Basin. The wet sub-period was also characterized by a larger contribution to rainfall by tropical cyclones and depressions. The findings suggest that a broadening of the Hadley circulation underpinned by an anomalous anticyclonic pattern to the east of southern Africa altered tropospheric steering flow, relative vorticity and moisture contents spatially during the subperiod of 8 years. These circulation modulations induced enhanced potential for tropical systems from the SWIO to cause precipitation over the Limpopo River Basin. The same patterns are also conducive to increasing rainfall over the larger subcontinent, therefore explaining the positive association in the bi-decadal rainfall cycle and rainfall contributed by tropical cyclonic systems from the SWIO. The regional circulation anomalies are also explained in hemispheric context, specifically in relation to the Southern Annular Mode, towards understanding variation over other parts of the Southern Hemisphere at this time scale.Water Research Commission (WRC Project No.K5/1847) in South Africa and the Agricultural Research Council (Project No. GW 50/053).http://link.springer.com/journal/382hb201