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The impact of age-related changes in the skull on sex estimation using morphoscopic traits
Houston, Sarah-Kelly; Brits, Desire; Myburgh, Jolandie; Liebenberg, Leandi (Springer, 2025-11)
The five sexually dimorphic traits of the skull described by Walker are frequently employed in skeletal analyses for sex estimation. Previous research has highlighted various changes in the craniofacial complex associated with advancing age, as cranial remodelling persists into adulthood. Age has been recognised as one potential factor contributing to misclassification when using the Walker traits. This study aimed to evaluate the influence of age on the expression of sexually dimorphic cranial traits and the impact of that influence on sex estimation in a South African sample. The traits were scored on a sample of 453 skulls between 14 and 108 years of age with an equal sex distribution. Only the nuchal crest exhibited significant differences in score distributions among the females in the sample, indicating differences between individuals younger than 40 years and those older than 40 years. Classification models showed a slight increase in accuracy for younger individuals when age-specific standards were applied, while accuracy for older individuals decreased slightly. However, the difference in accuracy with age-specific standards was comparable to accuracies obtained with all ages pooled. The results suggest age did not have as substantial an impact on trait expression as population affinity, and prior knowledge of age did not significantly influence the accuracy of the method. Thus, the pre-selection of age before the estimation of sex using the Walker traits is not currently necessary when conducting skeletal analyses in a contemporary South African population. However, the use of population-specific standards is paramount to more accurate classification.
Circulating microRNA profiles in pregnant South African women with different types of diabetes mellitus
Masete, Matladi Innocent; Dias, Stephanie; Malaza, Nompumelelo; Adam, Sumaiya; Mutavhatsindi , Hygon; Valverde-Tercedor, Carmen; Vega-Guedes, Begoña; Wägner, Ana Maria; Pheiffer, Carmen (MDPI, 2025-09-24)
Diabetes in pregnancy increases the risk of adverse perinatal outcomes for mother and child, with severity influenced by the type of diabetes and degree of hyperglycemia. This study aimed to identify circulating microRNAs (miRNAs) associated with different types of diabetes in pregnancy. Serum miRNAs were profiled in pregnant South African women with type 1 diabetes (T1DM), type 2 diabetes (T2DM), gestational diabetes (GDM), and normoglycemia using PCR arrays (n = 15). Differentially expressed miRNAs were validated in pregnant South African women (n = 167), and a separate cohort of Spanish pregnant women with T1DM and T2DM (n = 48). PCR arrays showed significant differential expression for miR-19b-3p (↓ 9.8-fold; p = 0.033) in GDM, miR-20a-5p (↓ 4.5-fold; p = 0.047) in T1DM, and miR-29a-3p (↑ 1.8-fold; p = 0.002) in T2DM compared to normoglycemia. Screening in the larger cohort showed lower expression of miR-20a-5p (↓ 2-fold; p = 0.013) in GDM and miR-30d-5p (↓ 2.1-fold; p = 0.032) in T1DM compared to normoglycemia. Additionally, miR-20a-5p levels were higher in women with T2DM compared to those with GDM (↑ 2.5-fold; p = 0.019). Our findings show that miRNA profiles are largely consistent across different types of diabetes in pregnancy, suggesting that hyperglycemia plays a key role in shaping miRNA expressions. Moreover, the identification of several shared gene targets suggests common underlying pathophysiological mechanisms.
Modelling factors associated with the probability of seeking traditional care after dog bites in Sierra Leone
Mshelbwala, Philip P.; Suluku, Roland; Anyasodor, Anayochukwu E.; Fadiji, Oyinkansola; Adamu, Andrew M.; Audu, Solomon W.; Sabeta, Claude Taurai; Rupprecht, Charles E.; Wangdi, Kinley (Elsevier, 2026-04)
Evidence suggests a rising incidence of dog bites in Sierra Leone despite ongoing efforts to prevent rabies. However, little is known about the factors influencing the decision to seek medical care following a dog bite. To address this gap, we developed a probabilistic model to examine factors associated with the likelihood of seeking traditional care in Sierra Leone. Among the 2558 respondents who completed the survey, 31 % (782/2558) indicated that they would seek traditional care after a dog bite. The posterior distributions of our model estimates indicated that the probability of seeking traditional care was higher among respondents with lower levels of education, those residing in rural areas, individuals lacking knowledge about rabies virus transmission and its hosts, and those who owned vaccinated dogs. Conversely, respondents living in locations with a livestock officer or veterinary establishment had lower odds of seeking traditional remedies compared with those uncertain about access. We observed a negative relationship between the percentage of health facilities and the probability of seeking traditional care, with higher percentages associated with a decreased likelihood of seeking traditional remedies. We also found regional variation in the probability of seeking traditional care. Respondents in the Eastern and Western Area were less likely to seek traditional remedies than those in the Northern and Southern Provinces. These findings highlight the need for targeted educational campaigns to raise awareness about rabies and the importance of timely medical care after exposure. Improving healthcare access in rural areas and fostering collaboration with traditional healers are also essential for reducing reliance on traditional care and strengthening rabies prevention and control efforts.
Modeling bounded count environmental data using a contaminated beta-binomial regression model
Otto, Arnoldus F.; Punzo, Antonio; Ferreira, Johannes T.; Bekker, Andriette, 1958-; Tomarchio, Salvatore D.; Tortora, Cristina (Wiley, 2026-01)
Bounded count data are commonly encountered in environmental studies. This paper examines two environmental applications illustrating their relevance. The first investigates the effect of winter malnutrition on mule deer (Odocoileus hemionus) fawn mortality. The second application analyzes public perceptions of environmental issues using data from the Eurobarometer 95.1 survey (March–April 2021), which includes a question rating the perceived severity of climate change on a scale from 1 to 10. Together, these studies demonstrate the need for flexible bounded count models in environmental research. In this context, the binomial and beta-binomial (BB) models are widely used for bounded count data, with the BB model offering the advantage of accounting for overdispersion. However, atypical observations in real-world applications may hinder the performance of the BB model and lead to biased or misleading inferences. To address this limitation, we propose the contaminated beta-binomial (cBB) distribution (cBB-D), which introduces an additional BB component to accommodate atypical observations while preserving the mean and variance structure of the BB model. The cBB-D thus captures both overdispersion and contamination effects in bounded count data. To incorporate explanatory variables, we further develop the contaminated BB regression model (cBB-RM), in which none, some, or all cBB parameters may depend on covariates. The proposed models are applied to two environmental datasets, complemented by a sensitivity analysis on simulated data to assess the influence of atypical observations on parameter estimation. The methodology is implemented in the open-source cBB package for R, available at https://github.com/arnootto/cBB.
Mini-review and situation report on the role and usefulness of nuclear medicine imaging for malaria
Duvenhage, Janie; Zeevaart, Jan Rijn; Sathekge, Mike Machaba; Ebenhan, Thomas (Springer, 2026-01)
Malaria remains one of the deadliest parasitic diseases globally. Delay or failure in treatment can lead to the development of severe malaria. Severe malaria, an understudied multisystem disease, affects the host’s organs and can lead to several syndromes and serious complications, some effecting life-long neurological and cognitive sequela. There is a lack in knowledge regarding the molecular mechanisms underlying severe malaria pathogenesis, and research has mostly relied on post-mortem studies and animal models, both of which lack translatability to human malaria. This review presents the clinical nuclear imaging techniques used in malaria. Although the presented radiopharmaceuticals have added value to understand some aspects of severe malaria, there has been in stagnation in development of more malaria-specific radiopharmaceuticals. This manuscript highlights the current limitations for implementing improved radiopharm