Search Results (3,785)

The transition of South Africa from coal-dependent energy systems to renewable energy alternatives presents economic and environmental trade-off complexities that require empirical investigation. This study employed threshold-switching dynamic models, NARDL analysis, and threshold Granger causality tests to investigate nonlinear relationships between renewable energy generation, economic growth, and carbon dioxide emissions in South Africa from 1980 to 2023. The threshold-switching dynamic models revealed critical structural breakpoints: a 56.4% renewable energy threshold for carbon dioxide emissions reduction, a 397.9% trade openness threshold for economic growth optimisation, and a 385.32% trade openness threshold for coal consumption transitions. The NARDL bounds test confirmed asymmetric effects in the carbon dioxide emissions and renewable energy relationship. The threshold Granger causality test established significant unidirectional causality from renewable energy to carbon dioxide emissions, economic growth to carbon dioxide emissions, and bidirectional causality between coal consumption and trade openness. However, renewable energy demonstrated no significant causal relationship with economic growth, contradicting traditional growth-led energy hypotheses. This study concluded that South Africa’s energy transition demonstrates distinct regime-dependent characteristics, with renewable energy deployment requiring critical mass thresholds to generate meaningful environmental benefits. The study recommended that optimal trade integration and renewable energy thresholds could fundamentally transform the economy’s carbon intensity while maintaining sustainable growth patterns. Full article

Achaea lienardi is a polyphagous moth occurring in sub-Saharan Africa. It is a fruit-sucking moth, causing secondary damage to fruit such as citrus and peaches, while the larval stage can cause significant tree defoliation, including in several indigenous trees, wattle, Eucalyptus, and castor oil plants, amongst others. In February and March of 2025, a massive outbreak of the caterpillars was observed in the Hluhluwe-iMfolozi Park in South Africa, feeding primarily on Tamboti trees (Spirostachys africana). Satellite imagery from the previous five years was examined, but no similar large defoliation events were observed during this period. Climate data for the last five years (September 2019–March 2025) were collated and examined to determine the conditions supporting the outbreak. Above average winter rainfall, early spring rains, sustained rains, and high humidity in January and February, with warm nighttime temperatures, likely acted in concert to create favourable conditions for the caterpillar outbreak. This outbreak coincided with historic outbreaks of the African armyworm (Spodoptera exempta) in the summer rainfall areas of South Africa where precipitation, temperature, solar radiation, and humidity were found to be critical factors affecting armyworm outbreaks. Further research is required to determine specific criteria to enable predictions of future outbreaks. Full article

This study presents a comprehensive investigation of a novel graphene oxide/zinc oxide/lignin (GO/ZnO/lignin) nanocomposite for the photocatalytic degradation of methylene blue (MB) and gentian violet (also known as crystal violet, CV) dyes in aqueous solutions. The nanocomposite was synthesized through a hydrothermal method and thoroughly characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). FTIR spectra confirmed the successful incorporation of functional groups from all components, while XRD patterns revealed a well-crystallized structure with characteristic peaks. SEM micrographs showed a uniform, hierarchical morphology and EDX analysis verified the elemental composition and distribution. Under ultraviolet (UV) irradiation, the nanocomposite exhibited remarkable photocatalytic degradation efficiency (~97%) for both MB and CV. Key operational parameters were systematically evaluated, including pH (2–10), catalyst dosage (0.005–0.04 g/20 mL), and initial dye concentration (10–20 ppm). Optimal performance was achieved at pH 10, with a catalyst dosage of 0.03–0.04 g/20 mL and lower dye concentrations. The enhanced photocatalytic activity can be attributed to the synergistic effects coming from GO’s electron transport capabilities, ZnO’s strong photocatalytic activity and lignin’s additional degradation sites. Furthermore, the nanocomposite demonstrated excellent reusability, retaining nearly 60% of its degradation capacity after four cycles, outperforming its individual components. These results highlight the potential of this composite material for sustainable wastewater treatment applications. Full article

Background and Objective: Thyroid cancer (TC) represents the most common group of endocrine tumors, and its incidence has increased over the last four decades. The imbalance of trace elements, such as zinc (Zn), has been investigated due to the thyroid’s sensitivity to these elements. Zn is essential for thyroid hormone action and may be involved in the pathogenesis of TC. This systematic review and meta-analysis aim to contribute to the discussion on the association between low serum Zn concentrations and the occurrence of TC. Materials and Methods: The search was carried out in the PubMed/MEDLINE, Scopus, Embase, LILACS and Web of Science databases, including observational studies published until December 2024. The primary outcome was low serum Zn concentration and the occurrence of TC. Three independent reviewers selected the studies and extracted the data from the original publications. The risk of bias was assessed using the Newcastle–Ottawa Quality Assessment Scale. Data analysis was performed using R software (V.4.3.1), and heterogeneity was calculated using the I² statistic, with results based on random effects models. Results: A total of 10 studies (n = 7 case–control and n = 3 cross-sectional) with sample sizes ranging from 44 to 294 individuals were included. The results indicated that serum Zn levels were not significantly lower in patients with TC compared with healthy controls (mean difference: −251.77; 95% confidence interval: −699.09, 195.54; I² = 100%, very low certainty). Conclusions: Further investigations, including rigorously designed observational studies with representative samples and improved control of potential confounding variables are indispensable. Full article

Introduction: Consumption of ultra-processed food (UPF) is associated with poor diet quality and a risk for non-communicable diseases (NCDs). This study explores the energy contribution of NOVA foods and the nutrient gaps. Methods: The study sourced data from the previous Ethiopian National Food Consumption Survey (NFCS). It covered 8254 households, 8254 women of reproductive age (15–45 years old), and 7272 children (6–45 months old). Results: The most consumed UPF in children were biscuits, cookies, soft drinks, and semi-solid palm oil; while cow and human milk, whole wheat bread, a range of legumes, tubers, and cereal-based foods were among NOVA1. In both children and women, the largest dietary energy intake was from NOVA1 (74.6% and 79.0%), processed culinary ingredients (18.3% and 14.0%), processed foods (1.9% and 3.5%), and UPF (5.1% and 3.5%), respectively. Higher intake of energy from UPF was found in urban residences, wealthier households, and women with higher education. However, NOVA1 was more dominantly consumed in rural than in urban areas. Micronutrient and macronutrient gaps were observed compared to the recommended nutrient intake (RNI). The intake of fruits and vegetables was also considerably low compared to the WHO recommendation (≥400 g/day for adults, and ≥250 g/day for children). Conclusions: Adequate intake of micronutrients, fruits, and vegetables is essential to meet the RNI and could have reduced existing body micronutrient deficiencies, such as vitamin A, zinc, iodine, calcium, vitamin D, and selenium prevalence. Whether UPF intake in urban areas is associated with insufficient availability and access to NOVA1 foods or just due to the higher provision of UPF and gained popularity needs additional investigation. Further study is recommended to simulate the impact of increased fruits and vegetables and/or reduced intake of selected UPF, salts, and oils on NCD markers or mortality in the country. Full article

Endothelial activation and cell adhesion molecules (CAMs) are exacerbated in the interaction of HIV infection and pre-eclampsia. This study compares the levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1), and E-selectin (sE-selectin) in HIV-infected normotensive pregnant versus pre-eclamptic women. We investigated the plasma concentration of sVCAM-1, sICAM-1, and sE-selectin in normotensive pregnant women (n = 40) and pre-eclamptic women (n = 40) using an immunoassay procedure. The concentrations of both sVCAM-1 (p < 0.0083) and sE-selectin (p < 0.0260) were significantly different from sICAM-1 in pre-eclampsia compared to normotensive pregnant groups, irrespective of HIV status. In contrast to sVCAM-1, sICAM-1 (p = 0.0349) and sE-selectin (p < 0.0445) concentrations were significantly elevated in HIV-positive compared to HIV-negative groups, regardless of pregnancy type. In pregnancies complicated by HIV, statistically significant differences in ICAM-1 concentration were observed between pre-eclamptic HIV-positive versus pre-eclamptic HIV-negative groups (p < 0.0010). Similarly, sVCAM-1 levels differed significantly between pre-eclamptic HIV-negative and normotensive HIV-positive groups (p < 0.0139). In contrast, sE-selectin levels varied significantly between pre-eclamptic HIV-positive versus normotensive HIV-negative groups (p < 0.0485). We report a dysregulation of sICAM-1, sVCAM-1, and SE-selectin in the co-morbidity of pre-eclampsia in pregnant women living with HIV. This differential expression may be attributed to oxidative stress emanating from the hypoxic endothelial activation in both pre-eclampsia and HIV infection and exacerbated by the immune restorative action of antiretroviral therapy. Full article

Background/Objectives: To evaluate the impact of the European–Mediterranean Postgraduate Program on Organ Donation and Transplantation (EMPODaT) on organ donation and transplantation (ODT) at 6 years. Methods: EMPODaT is a Trans-European Mobility Programme for University Studies (TEMPUS) project founded by the European Commission to address ODT professionals’ shortage in Middle East/North Africa (MENA) countries through structured postgraduate education. Leading universities from Spain, Germany, Sweden, and France, and key institutions in Egypt, Lebanon, and Morocco, developed a one-year blended training program incorporating e-learning, in-person courses, and hospital traineeships. The effect of the program at 6 years was analyzed by surveying the 90 healthcare participants. Results: A total of 73.9% of respondents remained actively engaged in the field, and some assumed leadership roles (local directors 14.4%, donor coordinators 13%). Also, 65.2% of participants reported improvements in policies and practices, with notable progress in donor screening (39.1%), brain death diagnosis (30.4%), and hospital policy reforms (69.7%). The study identified barriers, such as legal (34.4%), financial (34.8%), and public/social resistance (39.1%). Training alone, without strong hospital policies, support, and government involvement, was insufficient for introducing meaningful changes in ODT. Conclusions: Key aspects for successful implementation of training programs on ODT in MENA countries should consider hospital leadership engagement, strengthen institutional collaborations, and incorporate national health authorities to enhance sustainability and drive systemic changes. Prioritizing individuals in key decision-making positions could further enhance program effectiveness. Full article

This research examines the relationship between capital structure, intellectual capital, and financial performance among insurance companies in Sub-Saharan Africa (SSA). Anchored in a positivist paradigm, the study employed descriptive and quantitative methodologies, leveraging secondary panel data spanning from 2010 to 2022 across 122 insurance firms sampled from a population of 178 companies across 46 SSA countries. Utilizing a Panel Vector Error Correction Model (P-VECM), the analysis explored long-term equilibrium relationships and dynamic interactions among variables, including return on assets (ROAs), debt-to-equity ratio (DER), long-term debt (LTD), short-term debt (STD), Value-Added Intellectual Coefficient (VAIC™), and firm size (SIZE). Optimal lag lengths were determined through robust statistical criteria, ensuring model precision. The impulse response analysis revealed significant findings: variations in ROA negatively impacted intellectual capital (VAIC), leverage indicators (DER, LTD, and STD), and positively influenced firm size over a ten-period horizon. Specifically, decreases in ROA were consistently associated with reduced intellectual capital effectiveness and adverse financial liquidity conditions, while increased firm size correlated positively with improved financial performance. Full article

Background: Namibia is experiencing a generalized HIV epidemic, with 7.5% of the population living with HIV. Adolescent girls and young women (AGYW) aged 15–24 account for 28.6% of new infections annually. Various factors increase AGYW’s vulnerability to HIV. To address this, Project HOPE Namibia (PHN)-led consortium implemented the PEPFAR/USAID-funded DREAMS project in Khomas, Oshikoto, and Zambezi regions from 2018 to 2023. This study estimated the AGYW population most in need of HIV prevention and assessed geographic and age-specific gaps to improve program effectiveness and efficiency. Methods: This secondary data analysis utilized the Namibia Population-Based HIV Impact Assessment (NamPHIA) 2017, the Namibia census, and service data from the DREAMS project, which includes entry points for recruitment, screening, and enrolment. We used Python to conduct unadjusted and adjusted Poisson regression and UpSet plots for data visualization. Results: Analysis of NamPHIA data revealed low HIV prevalence in 10–14-year-olds, with only Oshikoto showing a detectable rate of 2.76%, mostly attributed to perinatal HIV transmission. Of the 12 DREAMS eligibility criteria, three could be mapped to 10–14-year-olds, while all except sexually transmitted infections could be mapped for 15–19 and 20–24-year-olds. Nationally, 17.3% of 10–14-year-old AGYW, 48.0% of 15–19-year-olds, and 50% of 20–24-year-olds met at least one DREAMS eligibility criterion. Among 15–19-year-olds, a history of pregnancy, no/irregular condom use, and out-of-school status were positively associated with HIV status. For 20–24-year-olds, transactional sex was positively associated with HIV status. Overall, 62% of screened individuals were eligible, and 62% of eligible individuals enrolled. PHN screened 134% of the estimated 37,965 10–14-year-olds, 95% of the estimated 35,585 15–19-year-olds, and 57% of the 24,011 20–24-year-olds residing in the five districts where DREAMS was implemented. Conclusions: We recommend the refinement of the DREAMS eligibility criteria, particularly for AGYW 10–14, to better identify and engage those at risk of HIV acquisition through sexual transmission. For 15–19-year-olds, PHN efforts should interrogate geographic variability in entry points for recruitment and screening practices. PHN should enhance the recruitment and engagement of AGYW 20–24, with a particular focus on those engaged in transactional sex. Full article

The application of artificial intelligence (AI) techniques has improved the accuracy of forest species identification, particularly in timber inventories conducted under Sustainable Forest Management (SFM). This study developed and evaluated machine learning models to recognize 16 Amazonian timber species using digital images of tree bark. Data were collected from three SFM units located in Nova Maringá, Feliz Natal, and Cotriguaçu, in the state of Mato Grosso, Brazil. High-resolution images were processed into sub-images (256 × 256 pixels), and two feature extraction methods were tested: Local Binary Patterns (LBP) and pre-trained Convolutional Neural Networks (ResNet50, VGG16, InceptionV3, MobileNetV2). Four classifiers—Support Vector Machine (SVM), Artificial Neural Networks (ANN), Random Forest (RF), and Linear Discriminant Analysis (LDA)—were used. The best result (95% accuracy) was achieved using ResNet50 with SVM, confirming the effectiveness of transfer learning for species recognition based on bark texture. These findings highlight the potential of AI-based tools to enhance accuracy in forest inventories and support decision-making in tropical forest management. Full article

Biodiversity conservation has been identified as an important climate change mitigation tool. Healthy ecosystems act as natural carbon sinks while also strengthening resilience, making them essential for climate change adaptation. Climate change effects have led to various negative impacts, including biodiversity loss and food insecurity. The loss of forest biodiversity threatens vital wild fruits and vegetables that sustain rural communities, disrupting natural food sources and constituting a form of social injustice for poor, vulnerable, and previously marginalised groups in rural and semi-urban communities. Therefore, this study aimed to investigate the relationship between previous biodiversity conservation outcomes, ecosystem services, highly utilised wild vegetables and fruits, food and nutritional security, climate change effects, and climate resilience. We identified gaps in African biodiversity conservation and developed a conceptual framework to highlight integral principles required for the effective biodiversity conservation of wild forests in Africa. The integral principles are active community engagement, a strong network of stakeholders, sustainable plant resources management practices, legal reforms, and the creation of awareness through various platforms. Conservation policies should prioritise African indigenous wild, drought-tolerant vegetables and fruits that serve as an interface between food and medicine; play various roles in human survival in the form of ecosystem services; and act as carbon sinks to ensure a food-secure future with reduced climate change effects. The African indigenous community’s efforts in biodiversity conservation engagements are key to successful outcomes. Full article

The present study characterizes the complete mitochondrial genome of Potamotrygon leopoldi, commonly referred to as the “white blotched stingray”, a member of the Potamotrygonidae family that are a group of stingrays that live exclusively in freshwater environments. Potamotrygon leopoldi, endemic to the Xingu River in the Amazon region, are exploited by commercial fisheries for food and commonly exploited by the ornamental industry, and this has a significant impact on the populations. Here, newly assembled PacBio long-read sequencing assesses the complete mitogenome of P. leopoldi and performs a comparative investigation into the evolutionary connections to other extant taxa of elasmobranchs. The mitogenome has 17,504 bp, containing 13 protein-coding, 22 tRNA, and 2 rRNA genes. The mitogenome comprises A: 32.32%, T: 24.41%, C: 12.84%, and G: 30.42%, with an AT content of 56.73%. The values of AT and GC skewness were 0.13 and −0.40, respectively. Our phylogenetic analyses with mitogenome sequences of 40 elasmobranch species support the monophyly for the Potamotrygonidae family and indicate a close relationship to the Dasyatidae family and a sister relationship with Potamotrygon orbignyi and Potamotrygon falkneri. We also detected various amino acid sites in positive selection exclusively in P. leopoldi. This extensive comparative mitogenomic investigation offers novel and significant insights into the evolutionary lineage of neotropical freshwater stingrays and their closely related taxa. It is an indispensable resource for facilitating ongoing and prospective investigations into the molecular evolution of elasmobranchs. Full article

Soybean (Glycine max (L.) Merrill) is highly sensitive to water deficit, particularly during the vegetative phase, when morphological and metabolic plasticity support continued growth and photosynthetic efficiency. We applied eleven water regimes, from full irrigation (W100) to total water withholding (W0), to plants grown under controlled conditions. After 14 days, we quantified morphophysiological, biochemical, leaf optical, gas exchange, and chlorophyll a fluorescence traits. Drought induces significant reductions in leaf area, biomass, pigment pools, and photosynthetic rates (A, g_s, ΦPSII) while increasing the levels of oxidative stress markers (electrolyte leakage, ROS) and proline accumulation. OJIP transients and JIP test metrics revealed reduced electron-transport efficiency and increased energy dissipation for many parameters under severe stress. Principal component analysis (PCA) clearly separated those treatments. PC1 captured growth and water status variation, whereas PC2 reflected photoprotective adjustments. These data show that progressive drought limits carbon assimilation via coordinated diffusive and biochemical constraints and that the accumulation of proline, phenolics, and lignin is associated with osmotic adjustment, antioxidant buffering, and cell wall reinforcement under stress. The combined use of hyperspectral sensors, gas exchange, chlorophyll fluorescence, and multivariate analyses for phenotyping offers a rapid, nondestructive diagnostic tool for assessing drought severity and the possibility of selecting drought-resistant genotypes and phenotypes in a changing stress environment. Full article

Erythrina caffra is a traditional plant used to treat cancer and inflammation. The study aimed to assess and isolate anticancer compounds from E. caffra bark. The plant material was extracted sequentially in n-hexane, dichloromethane, ethyl acetate and methanol. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and 3-(4,5-di methyl thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were used to evaluate the crude extracts’ antioxidant and anticancer activities, respectively. Column chromatography was used to purify the potent extracts of the stem bark in order to isolate the bioactive compounds. The crude extracts of the E. caffra bark demonstrated antioxidant and anticancer activity, with the dichloromethane (DCM) extract producing the most favorable activity. Three compounds, namely Hexacosanyl isoferulate, Tetradecyl isoferulate, and 1-Heneicosanol, were detected in fractions from the DCM extract. All the isolated compounds showed significant anticancer potential, with the hydroxycinnamic acid compounds showing better anticancer effects in the cervical (HeLa) and breast cancer (MCF-7) cells. The compounds showed greater activity than even the standard drug, 5-fluorouracil, in the MCF-7 cells, with the tetradecyl isoferulate and hexacosanyl isoferulate fractions having IC₅₀ values of 123.62 and 58.84 µg/mL, respectively. The compounds were observed to be capable of triggering caspase cascade events, leading to apoptotic cell death. Overall, E. caffra extracts contained important bioactive compounds that induced apoptotic cell death in HeLa and MCF-7 tumor cells, warranting further investigations in vitro and in vivo. Full article

The coracobrachialis muscle (CB) is a phylogenetically conserved component of the anterior compartment of the upper limb, offering critical insights into evolutionary anatomy, developmental biology, and human morphological variation. This mini review synthesizes findings from comparative anatomical studies, embryological data, cadaveric dissections, and clinical reports to explore the CB’s morphology, ontogeny, and medical relevance. Among tetrapods, the CB consistently originates from the coracoid process and inserts into the humerus, with interspecies morphological adaptations reflecting specific locomotor functions such as climbing, grasping, or digging. In humans, embryological studies confirm a common developmental origin with the biceps brachii, accounting for the frequent occurrence of variant configurations, including multiple heads and accessory slips such as the coracobrachialis longus (CBL) and brevis (CBB). These variants may contribute to clinical conditions such as musculocutaneous nerve entrapment+ or subcoracoid impingement. They may also be employed in reconstructive surgical procedures. A deeper understanding of CB morphology within an evolutionary framework improves anatomical interpretation, enhances clinical safety, and reduces diagnostic ambiguity. This review highlights the significance of integrating evolutionary and developmental perspectives in the study of human muscle variation. Full article