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N-doped activated carbon derived from water hyacinth for ultra-stable metal-free bifunctional electrode for zinc-air battery
No full textActivated N-doped carbon derived from water hyacinth leaves (WHL) was prepared and investigated as metal-free bi-functional catalyst for oxygen reduction and evolution (ORR/OER) in zinc-air batteries (ZABs). Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) methods were used to examine the morphology, elemental composition and the specific surface area of the samples, respectively. Linear sweep voltammetry (LSV) at rotating disk electrodes (RDEs) and rotating ring-disk electrodes (RRDEs) were employed to characterize the electrocatalytic activities. The electrochemical studies reveal that N-doped porous carbon from N-WHLs exhibited remarkable electrocatalytic activity for ORR, with an onset potential of 0.95 V and half-wave potential of 0.88 V comparable to commercial Pt/C catalyst. It also displays promising activity towards OER, with an overall potential of 1.86 V versus RHE to reach a current density of 10 mAcm, resulting in an oxygen electrode activity (OEA) value of 0.98 V. The percentage of hydrogen peroxide produced was significantly low, with average electron transfer number value of 3.94 at 0.8 V for N-WHL. Furthermore, the ZAB using N-WHL catalysts as an air cathode displayed a power density of 84 mW cm−2 and superior stability over 450 hours
Effective coverage measurements and cascade for maternal, newborn, child and adolescent health in high-income countries: systematic review
No full textBackground The concept of ‘effective coverage' (EC) aims to combine the j concept of coverage with the quality of care delivered and, ultimately, the health benefits received by the population in need. To date, systematic rej views of EC of maternal, newborn, child and adolescent health (MNCAH) have focused on low-and middle-income countries (LMICs). No review has j examined whether and how the concept has been applied in high-income j countries (HICs). To address this gap, this systematic review investigated the application of EC measures in MNCAH care in HICs. Methods This was a systematic review that followed the Preferred Report-jing Items for Systematic reviews and Meta-Analyses (PRISMA) reporting j guidelines. The search strategy was developed from previous EC reviews conducted in LMICs and further adapted to the HIC setting. Additional search terms were identified through discussion with experts from the Life Stage Quality of Care Metrics Technical Working Group subgroup on EC. We searched three databases, PubMed, Embase, and Web of Science, over 10 years. We conducted additional searches in Google Scholar and by con-j sulting members of the Life Stage Quality of Care Metrics Technical Work-j ing Group. We did not pose any language or type of article limits. Results The database search identified 18 976 studies for screening. Of these, 672 abstracts were screened, and none of the full texts considered met our inclusion criteria (e.g. human immunodeficiency virus/hepatitis c virus continuum of care cascade, intervention type, qualitative search-interviews/questionnaire type studies). Thirty-two articles were retrieved through the additional search strategies, and none were included because of LMIC-focused research. Therefore, examples of EC of MNCAH care ap-j plied in HICs were not identified. Conclusions Further investigation should be conducted into the application of the EC concept for assessing MNCAH care in HICs. This research will help us understand how this concept can be used to support health system effectiveness, efficiency, and equity in HICs. Registration The study protocol was registered at the Open Science Frame-j work: https://doi-org.ezproxy.uwc.ac.za/10.17605/OSF.IO/FMCG8
Coalition governance in South Africa’s local government: law and practice
No full textCoalition governments have the potential to promote inclusive, responsive and innovative governance and service delivery. However, they are inherently more complex than single-party governments due to the involvement of multiple coalition partners, whose diverse interests often poses a risk to political stability and effective governance. In municipalities, political stability is essential to ensure that municipal councils govern effectively and deliver essential services. Periods of political volatility in coalition governments can result in governance failures that adversely impact the functioning of municipalities. Where these failures affect municipalities’ ability to meet its executive obligations, municipalities become vulnerable to section 139 interventions, which include the dissolution of municipal councils. This qualitative study analyses international coalition traditions, court judgments and the institutional framework of South Africa’s local government to identify key barriers to political stability and service delivery in municipalities where coalition governance is the norm. The findings reveal that coalition-led municipalities often experience political instability caused by intra- and inter-party conflicts, rent-seeking motives or opportunistic behaviour, frequent termination of councillors’ party membership, removal of political office-bearers, biased enforcement of rules and orders, and increasing fragmentation. These constitute serious governance risks, as they undermine the ability of municipal councils to exercise their legislative and executive functions effectively and efficiently
HIV-1 viral protein effect on cerebral microvasculature: an in vitro blood–brain barrier model
No full textThe central nervous system (CNS) serves as a sanctuary for the Human Immunodeficiency Virus (HIV), which is facilitated by HIV's ability to breach the blood–brain barrier (BBB). BBB dysfunction occurs in the earliest stages of an HIV-1 infection. The immune-privileged CNS reduces harmful inflammatory responses, detrimental to the neuronal environment. BBB disruption, however, contributes to comorbidities in HIV, like cerebrovascular disease and neurocognitive problems. A 2-dimensional in vitro BBB model was employed to assess the effect of HL2/3 cell paracrine factors on select physiological parameters: cell proliferation, viability, toxicity, suppression, and morphology. BBB integrity was assessed using trans endothelial electrical resistance measurements. The study utilized immortalized mouse brain endothelial cell monocultures and co-cultures with the HL2/3 cell line, emulating an in vivo HIV-1 effect on the BBB.A concentration- dependent decline in cellular proliferation rates and viability was observed upon exposure to HL2/3 paracrine factors. Moreover, an elevation in cellular suppression, cell death, and cell toxicity was observed. Permeability studies confirmed decreased permeability after exposure to HIV-1 viral proteins in select in vitro BBB model systems. The impact of HIV viral proteins on brain capillary endothelium is critical to elucidate pathogen-induced cerebrovascular disease progression and vascular cognitive impairment in patients
The global, regional, and national burden attributable to low bone mineral density, 1990–2020: an analysis of a modifiable risk factor from the Global Burden of Disease Study 2021
No full textFractures related to osteoporosis and low bone mineral density lead to substantial morbidity, mortality, and cost to individuals and health systems. Here we present the most up-to-date global, regional, and national estimates of the contribution of low bone mineral density to the burden of fractures from falls and additional categories of injuries from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021. The burden of low bone mineral density was estimated from 1990 to 2020 in terms of years lived with disability (YLDs), disability-adjusted life years (DALYs), and deaths, for individuals aged 40 years and older, using data from population-based studies from 48 countries or territories (169 unique sources). Mean standardised femoral neck bone mineral density values were estimated by GBD location, age, and sex by meta-regression. Based on a separate meta-analysis of population-based studies from nine countries (12 unique sources), we also estimated the pooled relative risk of fractures per unit decrease in bone mineral density (g/cm²). The population-attributable fraction for low bone mineral density was calculated by comparing the observed distributions of standardised femoral neck bone mineral density to an age-specific and sex-specific counterfactual distribution, defined as the 99th percentile of five rounds of the National Health and Nutrition Examination Survey in the USA, by 5-year age group and sex. Hospital and emergency department data were used to derive the incidence of fractures for six categories of injury (road injuries, other transport injuries, falls, non-venomous animal contact, exposure to mechanical forces, and physical interpersonal violence) using ICD codes. Deaths due to fractures were estimated as the proportion of in hospital deaths due to the specified injury causes for which a fracture (nature of injury code) was more severe than the cause of injury code. YLDs and DALYs attributable to low bone mineral density by cause of injury were also determined according to previous GBD methods
Proximity to water shapes the distribution of natural elephant mortality in Hwange National Park, Zimbabwe
No full textWhile elephant poaching has received considerable attention, natural mortality can at times surpass human-induced deaths, especially under environmental stress. Understanding the ecological drivers of natural elephant mortality is therefore crucial for informing reintroduction efforts and preventing mass die-offs. In this study, we investigated environmental predictors of natural elephant mortality in Hwange National Park, Zimbabwe, using mortality records from 2020 to 2022. We applied four machine learning species distribution models, Random Forest, Gradient Boosting, Maximum Entropy, and Extreme Gradient Boosting, along with their ensemble to model mortality hotspots. The ensemble model outperformed individual models, achieving a True Skill Statistic of 0.54 and a Receiver Operating Characteristic of 0.83. Among all predictors, distance to water sources was the most influential variable (accounting for > 55% of model importance), with most mortalities occurring within 6 km of water points. Other key predictors included climate water deficit, normalized difference vegetation index (NDVI), tree cover percentage, and elephant density (each contributing > 5%). In contrast, maximum temperature of the warmest month and elevation had minimal predictive power (< 4%). Our results provide actionable insights for conservation planning. Areas close to water sources, particularly during dry periods, should be prioritized for monitoring and veterinary intervention. Meanwhile, regions with historically low mortality prevalences may serve as safer sites for reintroduction. This spatially explicit framework can help reduce post-release losses and enhance the long-term success of elephant conservation initiatives, especially in the face of ongoing environmental change
Premna sebrabergensis (Lamiaceae, Premnoideae), a new species from Angola and Namibia
No full textPremna sebrabergensis, hitherto misidentified in herbaria as Volkameria glabra (= Clerodendrum glabrum), is here described as a new species. It is a range-restricted species, only known from the Zebra Mountains in the Kaokoveld Centre of Endemism, in northwestern Namibia and southwestern Angola. It grows primarily in soils derived from anorthosite and gabbro of the Kunene Igneous Complex. Diagnostic characters for P. sebrabergensis include the pale green or yellow-green appearance of the plants, vegetative parts with an indumentum of simple antrorse-directed white trichomes and yellow glandular peltate scales, leaves usually ovate, often with elongated acuminate apex and flowers in paniculately arranged cymes. Based on IUCN Red List criteria, a provisional conservation assessment of Endangered (EN) is recommended for the new species
Adolescent flourishing in South Africa
No full textThe measurement of flourishing as an indicator of social progress has gained global recognition as a priority for governments. Adolescents, in particular, have been empirically identified as a population requiring more focused research on flourishing. In South Africa, understanding adolescent flourishing is especially critical given the country’s unique socio-cultural, economic, and historical context. This study examines flourishing among a sample of adolescents in the Western Cape Province of South Africa. We used data from a provincial survey on children’s well-being, which included a sample of 1045 adolescents between the ages of 13–19. We conceptualised flourishing as comprising both hedonic (feeling well) and eudaimonic (functioning well) components, including positive and negative affect, measured using four scales. Our analysis comprised a structural validation of the scales and measurement invariance testing across age and gender. We also report on the level of flourishing using mean scores and the percentage of scale maximum statistic. The results demonstrated appropriate fit for all the scales, with scalar measurement invariance tenable for all the scales across age and gender. The findings reveal generally high levels of well-being, though disparities in context-free life satisfaction and variations across demographic groups, highlighting the need for contextually-grounded assessments of adolescent flourishing. Overall, the study found high scores of flourishing, which is somewhat inconsistent with the objective realities experienced by adolescents in various contexts in South Africa
Women’s experiences of high-risk pregnancy care in resource constrained Cape Town communities
No full textA high-risk pregnancy elicits inherent fear for women, which has an impact that is great and far-reaching, often resulting in psychological health challenges both during and after pregnancy (minnaar 2020). Pregnancy is classified as high-risk when there is a possibility of difficulties during pregnancy, birth or the postpartum period, for either the mother or the growing baby (soh & nelson-piercy 2015). In low- and middle-income countries (lmics), where 99% of all maternal fatalities take place, women are more vulnerable to experiencing severe morbidity and mortality during pregnancy, delivery and the postpartum period (heitkamp et al. 2021).
It is widely known that healthcare institutions in lmics generally face considerable limitations (meghji et al. 2021). Therefore, socioeconomic factors that are highly linked to morbidity and mortality have had a significant influence on the health of the majority of south africans (militao et al. 2022).
Individuals in impoverished regions face systemic limitations that influence their behaviour (vilar- compte et al. 2021). For example, they are more likely to consume unhealthy food because of the limited access to nutritious grocery shopping options beyond convenience stores, liquor stores and fast-food establishments, which primarily serve high-fat, high-sugar and high-salt items (vilar- compte et al. 2021). These unhealthy alternatives may often lead to many women being at risk for major health issues, including obesity, hypertension and gestational diabetes, which might endanger both their lives and the lives of their unborn children (langley-evans 2022). Consequently, despite the south african government’s efforts to enhance care for expectant mothers and children, disparities in perinatal and maternal outcomes predominate and continue (ngene, khaliq & moodley 2023).
Although south africa’s health system was formerly segregated based on race, it continues to reflect the social divisions of the nation (maphumulo & bhengu 2019). For example, there are currently two healthcare systems – the public healthcare system which serves the poor majority and the private healthcare system which caters to those who occupy the higher socioeconomic status. Despite south african citizens being able to access free healthcare through the public healthcare system, a major drawback is that it is grossly underfunded despite servicing a large percentage (84%) of the population (maphumulo & bhengu 2019; mhlanga & garidzirai 2020). This challenge often manifests as long waiting periods for patients and a highly stressful working environment for healthcare professionals (crush & tawodzera 2014; wium, vannevel & bothma 2019).
In addition, south africa’s healthcare system is underpinned by the biomedical model, which views the human body as a mechanical, universal object that is devoid of culture (pentecost et al. 2018). According to this line of thinking, pregnancy is viewed as purely physical, which undercuts the significance that culture and experience have on pregnant women’s interpretation of their experiences (nuño de la rosa, pavličev & etxeberria 2021). Thus, interactions with clinical professionals often do not provide women with the necessary emotional and psychological fulfilment that they require.
Furthermore, african traditions and beliefs, which promote wholeness, a treatment approach that considers the full individual, including their social environment, stand in sharp contrast to the biomedical model (holst 2020). As a result, this system challenges south african society’s conventional, moral, and spiritual values. Moreover, according to the biological model paradigm, a pregnant woman is automatically at health risk, categorised as either ‘high–risk’ or ‘low–risk’ (majella et al. 2019). As a result, pregnancy has taken on a techno-medical aspect as medical experts approached it like a disease rather than something that is normal and natural (majella et al. 2019). Pregnant women are classified as ‘high-risk’ based on statistics rather than personal factors (van teijlingen et al. 2005).
This has given rise to the claim that giving birth is only safe in a hospital with medical staff present (yuill et al. 2020). Thus, a ‘high-risk’ label subsequently leads to intense monitoring and frequent interaction with healthcare providers (heemelaar et al. 2020). The ‘high-risk’ classification is an extremely stressful event that is intrinsically terrifying for women (minnaar 2020), making it crucial for healthcare providers to show compassion. However, the biomedical framework uses technical language which often leaves patients feeling left out as they are unable to comprehend their own diagnosis (khan 2019).
There are very few studies that have looked at women’s subjective experiences after a high-risk pregnancy in the setting of south africa. Despite it being well recognised that pregnancy affects a woman’s overall state of health and emotional well-being (abrar et al. 2020; cole-lewis et al. 2014), pregnancy is still viewed as a techno-medical event as researchers persist in concentrating on the physical conditions, ignoring the psychological distress that mothers face (nagar et al. 2015; torabi et al. 2012).
Women from developing countries are more exposed to stress and risk factors such as socioeconomic deprivation and poverty, increasing the likelihood for developing mental health problems (nielsen-scott et al. 2022). Given that one in five women residing in lmics experience a mental disorder during and after pregnancy (mitchell et al. 2023), it is unclear how south african women diagnosed with high-risk pregnancies interact with the healthcare system. Thus, the purpose of this study is to address this gap by investigating how a sample of women from resource-deprived neighbourhoods diagnosed with a high-risk pregnancy experienced the south african public healthcare syste
Cell viability assay of chitosan-modified glass Ionomer restorative cements
No full textPurpose: The present study evaluates the cytocompatibility of chitosan (CS)-modified glass ionomer cement (GIC) diluents for a Balb/c 3T3 fibroblast cell line.
Methods: Three different commercially available hand-mix GIC materials were used in this experiment: Fuji IX GP, Ketac Universal, and Riva Self Cure. The diluents for cell viability tests were produced from DMEM exposed to sterile CS-modified glass ionomer material specimens for three different time periods (0–1, 1–7, and 7–21 days). The resultant diluents were exposed to a 3T3 fibroblast cell line using the indirect contact technique in 96-well plates. In order to assess the physical cell response, five material specimens (1 mm high and 3 mm in diameter) of each material (n = 45) were produced and 3T3 cells were seeded on the specimens. SEM evaluation of the cells was conducted.
Results: All the Ketac Universal materials resulted in a decrease in cell viability on day 1. Fuji IX and the CS-modified GICs are the most consistent regarding cell viability. None of the CS-modified GICs exhibited improved cumulative cell biocompatibility. Conclusion: Two materials—Riva Self Cure modified with 5% and 10% CS—retained a decreased cell viability at day 21 compared to the viability of 3T3 cells exposed to the control DMEM