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A petrochemical investigation of the Spitskop Alkaline Complex, Eastern Transvaal
(University of Pretoria, 1976-10) Snyman, C.P.; Frick, C.; Nel, David. Jacobus
This study comprises a petrographical and mineralogical description of the rocks of the Spitskop Complex. Data on the chemical composition of the rock types, as well as on some of the minerals, are presented.
The complex consists of a pyroxenite pipe near the perimeter of which is situated a composite ring-dyke of foyaite. Ijolite is present as dykes and sills in the pyroxenite, and the carbonatite occurs as a plug intrusive into the pyroxenite. The complex is surrounded by an aureole of umptekite, and xenoliths of gabbroic rocks and magnetitite are present within the complex. A plug and sill of latite inside the complex, as well as dykes and cone sheets of latite and trachyte in the country rocks, were encountered.
Profiles of eight core boreholes, drilled to depths between 30 and 40 metres into the complex, are presented, together with thirty-two rock analyses, fifteen mineral analyses, and variation diagrams showing the chemistry of the clinopyroxenes.
The borehole profiles indicate that the ijolite is intrusive into the pyroxenite in the form of sills and dykes. This feature is further confirmed by the nature of the outcrops to the west of the carbonatite.
The foyaite is subdivided into porphyritic, hypidiomorphic, and trachytoidal textural varieties, and the ijolite into hypidiomorphic and porphyritic varieties. The chemical variation diagrams indicate that the clinopyroxenes of the alkaline rocks follow differentiation trends typical of alkaline complexes, whereas those of the theralites show trends similar to those usually found in layered intrusions.
From the geochemistry, the following order of emplacement may be derived: pyroxenite – ijolite – foyaite, in cases where a low CO₂ pressure prevailed in the magma; and pyroxenite – ijolite – carbonatite, in cases of a high CO₂ pressure.
The Upper Zone of the layered sequence of the Bushveld Complex is postulated as the source of the theralites, which are here interpreted as xenoliths within the Spitskop Alkaline Complex. A vertical displacement of not more than a few hundred metres is suggested.
Predicting cerebral palsy and 18-month neurodevelopmental outcome in infants with presumed hypoxic ischaemic encephalopathy : role of general movements assessment and early neurological examination
(Frontiers Media, 2025-10-03) Kali, Gugulabatembunamahlubi T.J.; Du Preez, Jacomina C.F.; Van Zyl, Jeanetta I.; Burger, Marlette; Katsabola, Hillary; Pepper, Michael Sean
INTRODUCTION : General movements assessment (GMA), including the Motor Optimality Score—Revised (MOS-R) and the Hammersmith Infant Neurological Examination (HINE), has been shown in different settings to predict cerebral palsy (CP) and delayed neurodevelopment with high accuracy. However, their combined predictive ability has not been fully evaluated in infants with presumed hypoxic–ischaemic encephalopathy (HIE).
OBJECTIVE : This study aimed to assess the predictive ability of combined GMA, MOS-R, and HINE at 3 months in term or near-term infants diagnosed with presumed HIE, for neurodevelopmental outcome at 18 months.
METHODS : A cohort of presumed HIE infants treated with therapeutic hypothermia (TH) underwent GMA, MOS-R, and HINE at 12–15 weeks, and neurodevelopmental assessments using the Bayley Scales of Infant and Toddler Development Third Edition (BSID-III) at 9–12 and at 18–24 months of age. Combined early assessments were analysed for their predictive ability across different domains on the BSID-III.
RESULTS : Twenty-four infants were included; 7 (29%) had both 12-month and 18-month BSID-III assessments, 12 (50%) were seen only at 12 months, and 5 (21%) only at 18 months. Two infants with absent fidgety movements (FMs) and poor motor repertoire were later diagnosed with CP or showed delays in two domains on the BSID-III assessment at 18 months. While most infants had some abnormality in the MOS-R categories, only absent FMs and abnormal finger variability showed some association with the 18-month BSID-III assessment on univariate analysis. Of the four infants classified as at risk for CP on the HINE at 3 months, two had some motor abnormalities at 18 months. Combining the GMA, MOS-R, and HINE had high sensitivity and negative predictive value (100%), but low specificity (0–17.6%) and positive predictive value (6.2%–25%) for the BSID-III outcome.
CONCLUSION : Combining GMA, MOS-R, and HINE was highly sensitive in this cohort, but had low specificity. This may lead to overdiagnosis, but it may be a useful screening tool for identifying typically developing infants who do not need intensive follow-up.
Minimal impact of feed intolerance during therapeutic hypothermia for hypoxic ischaemic encephalopathy in a South African cohort with a standardised feeding regimen
(Frontiers Media, 2025-07-30) Samaai, Ilhaam; Pepper, Michael Sean; Pillay, Shakti; Horn, Alan R.
INTRODUCTION : Enteral feeding during therapeutic hypothermia (TH) for neonatal hypoxic ischaemic encephalopathy (HIE), is beneficial, but there is insufficient evidence to guide timing and feed advancement strategies. The aim of this study was to describe feed tolerance and outcomes after TH with a standardized progressive early enteral feeding regimen.
METHODS : Data were retrospectively reviewed from neonates with HIE who were treated with TH for HIE in the Groote Schuur Hospital (GSH) Neonatal intensive care unit (NICU), between 1 July 2019 and 31 October 2022. Enteral feeds were commenced at age 12–24 h and incremented daily if tolerated, at 12 ml/kg/day for the first 3 days and 24 ml/kg thereafter. Nutritional, morbidity and mortality outcomes were compared between neonates with and without early feed intolerance (EFI) by the fourth day of life.
RESULTS : Thirty three percent (16/48) developed EFI. However, by day six the median (IQR) enteral volumes were, 120 (110–120) and 90 (90–99), in neonates without and with feed intolerance respectively. There were no differences in resuscitation characteristics. Neonates with EFI, had higher HIE grades, more amplitude integrated electro-encephalograph (aEEG) suppression at 48 h (p = 0.002), later attainment of full nutritive sucking or cup feeds (p < 0.001) and longer hospital stays (p = 0.038). There were no differences in other morbidities. Mortality was 6% and necrotising enterocolitis did not occur in either group.
CONCLUSIONS : Early feeding was generally well tolerated. Feed intolerance was more frequent in neonates with severe HIE, but most neonates achieved independence from IV fluids by day six.
Mapping the covariate-adjusted spatial effects of childhood anemia in Ethiopia using a semi-parametric additive model
(Frontiers Media, 2025-08-21) Yilema, Seyifemickael Amare; Shiferaw, Yegnanew A.; Nakhaeirad, Najmeh; Chen, Ding-Geng (Din)
BACKGROUND : Globally, anemia poses a serious health challenge for children under the age of five, and Ethiopia is one of the countries significantly affected by this issue. The 2016 Ethiopian Demographic and Health Survey (DHS) data sets were employed to evaluate anemia risk among children aged 6–59 months. Due to limited research has been conducted on childhood anemia spatial disparities at the Ethiopian zonal level, and it is essential for developing zonal-level interventions for inform policy recommendations.
METHODS : This study was examined the geospatial disparities in anemia prevalence among children aged 6–59 months. We used a semi-parametric additive model with spatial smoothing to assess zone-level variation in anemia risk while adjusting for key covariates. Each predictor variable was spatially adjusted using non-parametric smoothing techniques based on geolocation parameters, and corresponding maps for each predictor.
RESULTS : A regularized random forest techniques was employed to identify the most influential predictors of childhood anemia and enhance the model predictive performance. Our findings revealed that the regional states of Somalia, Afar, and Dire Dawa exhibit the highest risk levels for childhood anemia. Furthermore, the risk of anemia in children varies spatially across different zones in Ethiopia. The most prominent hotspots for childhood anemia were in the country's Northeastern, Eastern, and Southeastern regions. In contrast, the areas with the lowest risk were in Northwestern, Western, and Southwestern zones of Ethiopia.
CONCLUSION : The significant spatial disparities in anemia risk across the administrative zones of Ethiopia, indicating that the distribution of each predictor variable is not uniform. These findings provide valuable insights for policymakers, enabling the development of geographically targeted interventions to mitigate anemia risk at the zonal level.
Decision support system for Lespedeza cuneata production and quality evaluation : a WebGIS dashboard approach to precision agriculture
(Frontiers Media, 2025-07-17) Panda, Sudhanshu S.; Siddique, Aftab; Terrill, Thomas H.; Mahapatra, Ajit K.; Morgan, Eric; Pech-Cervantes, Andres A.; Van Wyk, Jan Aucamp
Small-scale farmers in the southeastern United States face increasing challenges in sustaining forage production due to erratic rainfall, poor soils, and limited access to precision agricultural tools. These constraints demand site-specific solutions that integrate climate resilience with sustainable land use. This study introduces a pioneering Site-Specific Fodder Management Decision Support System (SSFM-DSS) designed to optimize the cultivation of Lespedeza cuneata (sericea lespedeza), a drought-tolerant, nitrogen-fixing legume well-suited for marginal lands. By integrating high-resolution geospatial technologies—Geographic Information Systems (GIS), Global Navigation Satellite Systems (GNSS), and remote sensing—with empirical field data and predictive modeling, we have developed an automated suitability framework for SL cultivation across Alabama, Georgia, and South Carolina. The model incorporates multi-criteria environmental parameters, including soil characteristics, topography, and climate variability, to generate spatially explicit recommendations. To translate these insights into actionable strategies, we also developed a farmer-focused WebGIS Dashboard that delivers real-time, location-based guidance for SL production. Our findings underscore the significant potential of SSFM-DSS to enhance fodder availability, improve system resilience under climate stress, and promote sustainable livestock production. This integrative approach offers a promising pathway for climate-smart agriculture, supporting broader food security objectives in vulnerable agroecosystems.