The prevalence of anaemia and selected micronutrient status in pregnant teenagers of Polokwane Municipality in the Limpopo Province

Objective: The objective of this study was to determine the iron, folate and vitamin B12 status of pregnant teenagers in the Limpopo Province. Design: This is a descriptive study with analytical components. Methods: Pregnant teenagers aged between 12 and 21 years were recruited from Mankweng, Dikgale, Makotopong and Kganya clinics in the Limpopo Province, South Africa. Dietary data and blood were collected for the analysis of iron, folate and vitamin B12 status. Outcome measures: Blood was collected for the analysis of iron, folate and vitamin B12 status. Dietary data were collected using a repeated 24-hour recall questionnaire and a food frequency questionnaire, and demographic data were also collected using a standard questionnaire. Results: The mean and standard deviation for iron, folate, vitamin B12 and vitamin C were 6.5 mg ± 3.3, 155.3 μg ± 92.7, 2.3 μg ± 2.8 and 31.2 mg ± 36.2 respectively. The prevalence of anaemia was high (36%), with iron deficiency anaemia being the most prevalent (57%) as compared to either folate (9%) or vitamin B12 (7%) deficiency anaemia. There was a significant difference (p = 0.03) in serum folate between teenagers who were receiving folic acid supplements and those who were not receiving any such supplements. Conclusions: More than a third of the teenagers were anaemic and this is considered to be high. These teenagers need nutrition education so that they will be able to choose nutritious food, especially at a critical stage such as pregnancy. SAJCN Vol. 21 (4) 2008: pp. 332-33

Simulation of an evolving convective boundary layer using a scale-dependent dynamic Smagorinsky model at near-gray-zone resolutions

A scale-dependent Lagrangian-averaged Dynamic Smagorinsky sub-grid scheme with stratification effects is used to simulate the evolving convective boundary layer of the Wangara case study in the grey-zone regime (specifically, for grid lengths from 25 to 400 m). The dynamic Smagorinsky and standard Smagorinsky approaches are assessed for first and second order quantities in comparison with results derived from coarse-grained LES fields. In the LES regime the sub-grid schemes produce very similar results, albeit with some modest differences near the surface. At coarser resolutions, the use of the standard Smagorinsky significantly delays the onset of resolved turbulence, the delay increasing with coarsening resolution. In contrast, the dynamic Smagorinsky scheme much improves the spin-up and so is also able to maintain consistency with the LES temperature profiles at the coarser resolutions. Moreover, the resolved part of the turbulence reproduces well the turbulence profiles obtained from the coarse-grained fields, especially in the near grey-zone. The dynamic scheme does become somewhat over-energetic with further coarsening of the resolution, especially near the surface. The dynamic scheme reaches its limit in our current configuration when the test filter starts to sample at the unresolved scales returning very small Smagorinsky coefficients. Sensitivity tests reveal that the dynamic model can adapt to changes in the imposed numerical or sub-grid diffusion by adjusting the Smagorinsky constant to the changing flow field and minimising the dissipation effects on the resolved turbulence structures

Resolution dependence of turbulent structures in convective boundary layer simulations

Large-eddy simulations are performed using the UK Met Office Large Eddy Model to study the effects of resolution on turbulent structures in a convective boundary layer. A standard Smagorinsky subgrid scheme is used. As the grid length is increased the diagnosed height of the boundary layer increases and the horizontally- and temporally-averaged temperature near the surface and in the inversion layer increase. At the highest resolution, quadrant analysis shows that the majority of events in the lower boundary layer are associated with cold descending air, followed by warm ascending air. The largest contribution to the total heat flux is made by warm ascending air, with associated strong thermals. At lower resolutions, the contribution to the heat flux from cold descending air is increased and that from cold ascending air is reduced in the lower boundary layer; around the inversion layer, however, the contribution from cold ascending air is increased. Calculations of the heating rate show that the differences in cold ascending air are responsible for the warm bias below the boundary layer top in the low resolution simulations. Correlation length and time scales for coherent resolved structures increase with increasing grid coarseness. The results overall suggest that differences in the simulations are due to weaker mixing between thermals and their environment at lower resolutions. Some simple numerical experiments are performed to increase the mixing in the lower-resolution simulations and to investigate backscatter. Such simulations are successful in reducing the contribution of cold ascending air to the heat flux just below the inversion, although the effects in the lower boundary layer are weaker

Northern Sotho historical dramas : a historical-biographical analysis

The main aim of the study is to make a historical-biographical analysis of four selected Northern Sotho dramatic texts. Chapter one illustrates that the texts we have selected are historical dramas since they deal with the life histories of historical characters. In order to comprehend these texts, it is important to view them as evidence of oral history. The chapter also discusses the approach used by Fleischman which consists of the following parameters: authenticity, intention, reception, social function, narrative syntax and finally narrator involvement. Chapter two discusses the play Marangrang as a reflection of the consequences of Shaka's imperialism and how this affected the Eastern Transvaal in 1820. The chapter illustrates that in order to understand the life history of Marangrang, it is important to discuss it in relation to this period, popularly known as difaqane. It is clear that information about Marangrang has been deliberately distorted because of fear. Chapter three deals with the destructive consequences of Western religion on the traditional African religion. The chapter is based on the life history of Kgasane, who was murdered in 1884, allegedly for his devotion to Christianity. The chapter shows the importance of the need to make a re-interpretation of missionary writings, specifically those surrounding the Berlin Mission Society in South Africa. Chapter four focuses on the role of formal education in the destruction of the Bakgaga ba GaMphahlele history. The chapter is based on the life history of Kgosi Mmutle Ill in bringing formal education to the people of Mphahlele and how this destroyed certain traditional institutions such as chieftainship. Chapter five deals with the problems experienced by mineworkers and also shows the sufferings of Africans at the hands of the government. The chapter is based on the life of Serogole Mathobela, who once worked in the mine. Chapter six is a conclusion where the findings of the previous chapters are made. The reasons why the authors of these texts suspended certain information while highlighting other information varies from fear to propaganda. In conclusion, it is observed that in order to do justice to oral history more financial support is needed.African LanguagesD.Litt. et Phil. (African Languages

A quasi-geostrophic analysis of summertime southern African linear-regime westerly waves

Linear-regime westerly waves that propagate across the South African domain are often linked to well-known rainfall producing systems such as tropical temperate troughs and synoptic scale tropical low-pressure systems, and ridging South Atlantic Ocean anticyclones at the surface. It is accepted that the baroclinic waves that propagate across the domain provide the lifting mechanism that causes the required vertical motion for rainfall to occur. This study shows that there exists a jet streak embedded in these waves that is located downstream of the trough axis, to the east of which vertically upward motion is expected to occur. The entrance of the jet streak passes just south of the country, as the waves propagate past the domain. The study further shows that for this class of waves, the vertical motion that causes rainfall to occur is induced by the thermally direct transverse ageostrophic circulation that is located at this jet entrance. This is instead of the conventional upper air divergence that is located at the infection point east of the trough axis. Using a method of decomposing the Q-vector into its transverse (Qn) and shear (Qs) components, the divergence felds of which are used to decompose the vertical motion into the corresponding components, i.e 휔n and 휔s, respectively; it was shown that the vertical motion over South Africa is explained more by the former than the latter. Therefore, the uplift over the country and that located at the infection point east of the trough are dynamically distinct processes. Taking the limitations of the quasi-geostrophic framework into consideration, the study concludes that during the passage of linear-regime waves vertical motion that might lead to rainfall is caused by the circulation at the jet entrance and not the divergence in the baroclinic wav

Projections of rapidly rising surface temperatures over Africa under low mitigation.

An analysis of observed trends in African annual-average near-surface temperatures over the last five decades reveals drastic increases, particularly over parts of the subtropics and central tropical Africa. Over these regions, temperatures have been rising at more than twice the global rate of temperature increase. An ensemble of high-resolution downscalings, obtained using a single regional climate model forced with the sea-surface temperatures and sea-ice fields of an ensemble of global circulation model (GCM) simulations, is shown to realistically represent the relatively strong temperature increases observed in subtropical southern and northern Africa. The amplitudes of warming are generally underestimated, however. Further warming is projected to occur during the 21st century, with plausible increases of 4-6 °C over the subtropics and 3-5 °C over the tropics by the end of the century relative to present-day climate under the A2 (a low mitigation) scenario of the Special Report on Emission Scenarios. High impact climate events such as heat-wave days and high fire-danger days are consistently projected to increase drastically in their frequency of occurrence. General decreases in soil-moisture availability are projected, even for regions where increases in rainfall are plausible, due to enhanced levels of evaporation. The regional dowscalings presented here, and recent GCM projections obtained for Africa, indicate that African annual-averaged temperatures may plausibly rise at about 1.5 times the global rate of temperature increase in the subtropics, and at a somewhat lower rate in the tropics. These projected increases although drastic, may be conservative given the model underestimations of observed temperature trends. The relatively strong rate of warming over Africa, in combination with the associated increases in extreme temperature events, may be key factors to consider when interpreting the suitability of global mitigation targets in terms of African climate change and climate change adaptation in Africa.SP2016http://iopscience.iop.org/article/10.1088/1748-9326/10/8/08500

Convective initiation and storm life‐cycles in convection‐permitting simulations of the Met Office Unified Model over South Africa

Convective initiation is a challenge for convection‐permitting models due to its sensitivity to sub‐km processes. We evaluate the representation of convective storms and their initiation over South Africa during four summer months in Met Office Unified Model simulations at 1.5‐km horizontal grid length. Storm size distributions from the model compare well against radar observations, but rainfall in the model is predominantly produced by large storms (50 km in diameter or larger) in the evening, whereas radar observations show most rainfall occurs throughout the afternoon, from storms 10‐50 km in diameter. In all months, modelled maximum number of storm initiations occurs at least 2 hours prior to the radar‐observed maximum. However, the diurnal cycle of rainfall compares well between model and observations, suggesting the numerous storm initiations in the simulations do not produce much rainfall. Modelled storms are generally less intense than in the radar observations, especially in early summer. In February, when tropical influences dominate, the simulated storms are of similar intensity to observed storms. Simulated storms tend to reach their peak intensity in the first 15 minutes after initiation, then gradually become less intense as they grow. In radar observations, storms reach their peak intensity 15‐30 minutes into their life cycle, stay intense as they grow larger, then gradually weaken after they have reached their maximum diameter. Two November case studies of severe convection are analysed in detail. Higher resolution grid length initiates convection slightly earlier (300 m cf. 1.5 km) with the same science settings. Two 1.5‐km simulations that apply more sub‐grid mixing have delayed convective initiation. Analysis of soundings indicates little difference in convective indices, suggesting that differences in convection may be attributed to choices in sub‐grid mixing parameters

Evaluating South African Weather Service information on Idai tropical cyclone and KwaZulu-Natal flood events

Severe weather events associated with strong winds and flooding can cause fatalities, injuries and damage to property. Detailed and accurate weather forecasts that are issued and communicated timeously, and actioned upon, can reduce the impact of these events. The responsibility to provide such forecasts usually lies with government departments or state-owned entities; in South Africa that responsibility lies with the South African Weather Service (SAWS). SAWS is also a regional specialised meteorological centre and therefore provides weather information to meteorological services within the Southern African Development Community (SADC). We evaluated SAWS weather information using near real-time observations and models on the nowcasting to short-range forecasting timescales during two extreme events. These are the Idai tropical cyclone in March 2019 which impacted Mozambique, Zimbabwe and Malawi resulting in over 1000 deaths, and the floods over the KwaZulu-Natal (KZN) province in April 2019 that caused over 70 deaths. Our results show that weather models gave an indication of these systems in advance, with warnings issued at least 2 days in advance in the case of Idai and 1 day in advance for the KZN floods. Nowcasting systems were also in place for detailed warnings to be provided as events progressed. Shortcomings in model simulations were shown, in particular on locating the KZN flood event properly and over/-underestimation of the event. The impacts experienced during the two events indicate that more needs to be done to increase weather awareness, and build disaster risk management systems, including disaster preparedness and risk reduction.Significance: This paper is relevant for all South Africans and the SADC region at large because it provides information on: the weather forecasting processes followed at the South African Weather Service, available early warning products in South Africa and for the SADC region made possible through the public purse, the performance of nowcasting and modelling systems in the case of predicting two extreme weather events that had adverse impacts on southern African society, and the dissemination of warnings of future extreme weather events

Sensitivity of tropical cyclone Idai simulations to cumulus parametrization schemes

Weather simulations are sensitive to subgrid processes, that are parameterized in numerical weather prediction (NWP) models. In this study, we investigate the response of tropical cyclone Idai simulations to different cumulus parameterization schemes, using the Weather Research and Forecasting (WRF) model with a 6 km grid length. Seventy-two hour (00 UTC 13 March to 00 UTC 16 March) simulations are conducted with the New Tiedtke (Tiedtke), New Simplified Arakawa Schubert (NewSAS), Multi-scale Kain Fritsch (MSKF), Grell-Freitas, and the Betts-Miller-Janjic (BMJ) schemes. A simulation for the same event is also conducted with the convection scheme switched off. The twenty-four hour accumulated rainfall during all three simulated days is generally similar across all six experiments. Larger differences in simulations are found for rainfall events away from the tropical cyclone. When the resolved and convective rainfall are partitioned, it is found that the scale-aware schemes (i.e. Grell-Freitas and MSKF) allow the model to resolve most of the rainfall, while they are less active. Regarding the maximum wind speed, and minimum sea level pressure (MSLP), the scale aware schemes simulate a higher intensity that is similar to the Joint Typhoon Warning Center (JTWC) data set, however the timing is more aligned with the Global Forecast System (GFS), which is the model providing initial conditions and time dependent lateral boundary conditions. Simulations with the convection scheme off were found to be similar to those with the scale-aware schemes. It is found that Tiedtke simulates the location to be farther south west compared to other schemes, while BMJ simulates the path to be more to the north after landfall. All of the schemes as well as GFS failed to simulate the movement of Idai into Zimbabwe, showing potential impact of shortcomings in the forcing model. Our study shows that the use of scale aware schemes allows the model to resolve most of the dynamics, resulting in higher weather system intensity in the grey zone. The wrong timing of the peak shows a need to use better performing global models to provide lateral boundary conditions for downscalers

Reconsidering Priorities for Digital Maternal and Child Health: Community-Centered Perspectives from South Africa

Especially in developing regions, parents are rarely given a direct voice in the design of digital maternal and child health (MCH) interventions. Instead, MCH needs and requirements are driven by organizations and health workers. In this research, we engage with both rural and urban parents and community leaders to better understand their challenges and priorities for digital MCH and propose a parent-centered agenda for human-computer interaction research. This paper reports on the community-based, digital MCH priorities identified in our research, and describes how we approached community discourse and co-design of digital initiatives for these priorities, through parent-centered workshops with low-resource South African communities. Furthermore, we provide the parent-centered design opportunities and tensions we discovered for digital MCH in South African contexts, such as designing for local contexts and languages, designing for accessibility and connectedness, and highlighting the underdeveloped digital MCH niches. Finally, we highlight the importance of including facilitators for co-design workshops, such as using intermediaries and design cards