Search Results (216)

Cold stress is a major environmental constraint limiting the growth, physiological performance, and productivity of African marigold (Tagetes erecta L.) under open-field conditions. This study evaluated the comparative effectiveness of salicylic acid (SA), silicon (Si), and methyl jasmonate (MeJA) in alleviating cold-induced damage and enhancing stress tolerance. Field experiments were conducted under naturally occurring cold stress using foliar applications of SA (0, 0.1, 0.5, and 1 mM), Si (0, 1, 5, and 10 mM), and MeJA (0, 10, and 50 µM) in a complete randomized block design with three replications. Moderate concentrations of all three regulators significantly (p < 0.05) improved plant growth and physiological stability relative to untreated controls. Salicylic acid at 0.5 mM produced the most consistent protective response, increasing biomass accumulation, chlorophyll content, and relative water content while reducing membrane damage, as indicated by a 42.3% decrease in leaf electrolyte leakage at 2 °C. Silicon at 10 mM enhanced membrane integrity, plant water status, and vegetative growth under low-temperature conditions, while methyl jasmonate at 10 µM mitigated cold-induced membrane damage and improved physiological tolerance, whereas higher concentrations (50 µM) were less effective. At their optimal doses, SA, Si, and MeJA increased plant dry mass by 39.7%, 30.1%, and 38.5%, respectively. Correlation analysis confirmed these results, revealing strong positive relationships among growth, chlorophyll, and relative water content. Conversely, electrolyte leakage was negatively correlated with biomass and water status, identifying membrane stability as a key determinant of cold tolerance. Overall, 0.5 mM SA, 5–10 mM Si, and 10 μM MeJA improved growth and key physiological responses in African marigold under cold stress under field conditions. Future studies should integrate mechanistic and economic analyses to refine growth-regulator-based cold-stress management strategies. Full article

In genetics and evolutionary biology, selection signatures refer to distinct genomic patterns that reflect the action of natural and artificial selection on populations over time. Detecting such signatures provides critical insights into adaptive evolution and breed differentiation, especially in livestock populations subjected to diverse production environments and breeding objectives. In this study, a total of 96 samples were collected from four different cattle breeds, namely, South African indigenous Nguni (n = 28), Bonsmara (n = 21), Angus (n = 22), and Simmental (n = 25). The samples were genotyped using the Illumina Bovine SNP 150K BeadChip and subjected to quality control. Selection signatures were identified using the integrated haplotype score (iHS) method and the fixation index (Fst) method to assess the genetic differences between breeds. The complementary application of within-population and cross-population approaches enabled the detection of both recent and divergent selective pressures. A total of twelve regions were found to be under selection, with Bos taurus autosome (BTA) 12 being common between Nguni and Bonsmara. Gene annotation analyses identified several genes, including FAM110B, CDK8, and FLT1 in Bonsmara cattle, whereas Nguni cattle indicated potential genes such as CRB1, PLA2G4A, and VASH2, with CDK8 common between Bonsmara and Nguni on BTA 12. Cross-population analyses further identified PLCXD3, FAM149B1, and GRIK2 as candidate genes differentiating Bonsmara from Nguni cattle, and TSPAN9 distinguishing Simmental from Angus cattle. These results indicated breed-specific adaptive divergence. The study revealed genomic regions that are under selection in South African Nguni, Bonsmara, and Simmental cattle, with less information for Angus cattle breeds. Several candidate genes were found to be associated with reproductive traits (such as sperm count and inseminations per conception), disease resistance (such as bovine respiratory disease), and calving ease. This study identifies breed-specific and shared genomic regions under selection across diverse cattle breeds, providing novel insights into the genetic basis of adaptation and production-related traits. These findings explain the potential application of selection signature analyses in genomic-assisted breeding programmes aimed at improving productivity, resilience, and sustainability of cattle populations. Full article

Marine macroalgae are a rich source of bioactive natural products, although the application of many lipophilic compounds is limited by poor aqueous solubility and instability. This study investigated metabolites isolated from the South African brown seaweed Sargassum incisifolium and evaluated a solid lipid nanoparticle (SLN) system to improve their physicochemical properties and enable bioactivity studies. Five metabolites, including one previously unreported derivative and four known metabolites (including fucoxanthin), were isolated and characterized using standard chromatographic and spectroscopic techniques. SLNs composed of stearic acid and Poloxamer 188 were prepared via hot homogenization and characterized using dynamic light scattering, scanning electron microscopy, thermogravimetric analysis, and NMR, which confirmed the efficient encapsulation of the lipophilic compounds. Antimicrobial activity against clinically relevant bacterial and fungal pathogens was evaluated using a resazurin-based microdilution assay, with results expressed as percentage growth relative to untreated controls. The pure compounds exhibited moderate, concentration-dependent activity, while the SLN formulations improved dispersibility, and in several cases, reduced % growth or produced more consistent responses, particularly against Gram-positive bacteria and Candida auris. Although activity remained lower than that of conventional antimicrobials, these findings demonstrate that SLN-based delivery enables functional evaluation of hydrophobic marine metabolites and supports further development of Sargassum-derived natural products. Full article

This paper investigates the role of financial institution development in promoting renewable energy generation in African economies. The paper is motivated by the increasing global emphasis on clean energy transition and the need to achieve the Sustainable Development Goals, particularly those related to affordable and clean energy and climate action. It focuses on identifying the mechanisms through which financial development influences renewable energy outcomes. Grounded in the Schumpeterian theory of finance, the paper argues that financial institutions facilitate innovation and structural transformation by allocating resources toward productive investments, including renewable energy projects. The analysis examines whether credit to the private sector serves as a mediating channel in this relationship. It also evaluates the moderating roles of institutional quality and natural resource rents. Using a Panel Autoregressive Distributed Lag (PARDL) model within a dynamic fixed-effects error correction framework, the findings reveal a nonlinear relationship. Financial institution development initially promotes renewable energy generation, but its positive effect weakens beyond a threshold of resource dependence. Institutional quality strengthens the effectiveness of financial development, while credit to the private sector fully transmits its impact on renewable energy generation. The results highlight the importance of strengthening financial systems, improving governance, and enhancing private sector credit allocation to support sustainable energy development in Africa. Full article

South African irrigation schemes face critical challenges of water scarcity, infrastructure deterioration, and limited monitoring capacity, threatening agricultural productivity and food security. This scoping review systematically analyses 59 peer-reviewed publications (2000–2025) on sensor-based and acoustic irrigation monitoring technologies in South Africa, using transformer-based natural language processing (Sentence-BERT embeddings), unsupervised Machine Learning (UMAP dimensionality reduction, HDBSCAN clustering), and geospatial mapping applied to literature retrieved from Web of Science and Scopus. Results show that water quality monitoring (42.4% of studies) and remote sensing (25.4%) dominate the national research landscape, while soil moisture sensing and modelling remain comparatively limited. Notably, no peer-reviewed studies applying acoustic monitoring technologies to irrigation were identified, representing a critical gap despite proven international applications for leak detection (95–98% accuracy), widespread infrastructure aging (over 50% of schemes exceeding 30 years), and reported water losses of 30–60% in poorly managed systems. Reported experimental water savings range from 15% to 30%, yet applications remain largely confined to pilot-scale implementations concentrated within a limited number of Water Management Areas. Persistent adoption barriers include infrastructure unreliability, financial inaccessibility, limited digital literacy, and weak institutional coordination. The review recommends: (i) expanding research coverage across underrepresented regions and Water Management Areas; (ii) strengthening extension support and technical training to enable broader adoption; and (iii) integrating low-cost sensor networks with predictive, data-driven irrigation advisory systems. These priorities aim to support scalable, context-sensitive irrigation modernisation under increasing water scarcity pressures. Full article

Feed availability and quality remain major constraints to ruminant productivity in West Africa, where livestock systems rely heavily on locally available resources such as natural forages, crop residues and agro-industrial by-products. However, reliable ration formulation requires accurate information on feed chemical composition, while existing data are fragmented and highly variable. This study conducted a systematic review of peer-reviewed literature published between 2000 and 2025 to synthesize available data on the chemical composition of ruminant feeds in West Africa. Following PRISMA guidelines, 44 studies reporting quantitative feed composition data were retained. Feed resources were classified into agro-industrial by-products, agricultural by-products and forages, and descriptive statistics were calculated for key nutritional parameters. The results revealed substantial variability in nutrient composition across feed types and even within the same feed resource. Cottonseed cake emerged as a major protein-rich supplement, legume haulms showed higher nutritional value than cereal residues, and several browse species such as Moringa oleifera and Leucaena leucocephala demonstrated high protein potential. These findings highlight that fixed feed composition values are poorly suited to heterogeneous tropical feeding systems. The reference ranges established in this review provide a more reliable basis for feed evaluation and ration formulation and can support the development of locally adapted feeding strategies and decision-support tools for West African livestock systems. Full article

Legume crops, such as the common bean (Phaseolus vulgaris L.), are significant in many Sub-Saharan African (SSA) countries, including Eswatini, due to their numerous health benefits, including high protein, fiber, vitamins, and mineral content. Common beans are a staple food in many parts of the world and play a crucial role in nitrogen fixation, thereby improving soil fertility. A field experiment was conducted at Malkerns research station, Eswatini, using 27 common bean genotypes to assess their ability for N-fixation and water relations using the ¹⁵N and ¹³C natural abundance techniques. The data revealed significant differences among the common bean genotypes. Genotypes Cim-Rm-36 and Mwctz20a-Rm19 recorded an increase in plant growth by (6% and 5.74%), N content (5.69% and 5.97%) and greater C content (6.1% and 5.67%) while genotype Mwctz20a-Rm19 also showed an increase in N-fixation (155.73 kg.ha⁻¹). Genotype Mwctz20a-Rm-4 had the highest grain yield (1747.39 kg.ha⁻¹), while genotype Cim-Rm-14-Als61 had the highest N concentration (3.50%), indicating efficient N uptake. The genotypes with the lowest δ¹³C values (−27.38‰ to −28.06‰) suggested similar water use efficiency among the genotypes. The findings of this study revealed that common beans can make a significant contribution to N fertility under drought conditions. Genotypes Cim-Rm-36, Mwctz20a-Rm19, and Mwctz20a-Rm-4 showed desirable characteristics and can be good candidates for possible inclusion in breeding programs. These results have implications for improving common bean production in drought-prone areas and promoting sustainable agriculture practices. Full article

Despite widespread corporate endorsement of the Sustainable Development Goals (SDGs), systematic evidence on how top management in emerging economies prioritizes and frames SDG-related issues over time remains limited. Existing studies are often based on manual or single-year analyses, restricting comparability, scalability, and longitudinal insight. This study examines how corporate managerial communication aligns with and emphasizes SDGs across sectors and over time in two major emerging economies, India and South Africa. Using an AI-driven natural language processing (NLP) pipeline, we analyse 2400 annual reports from 600 publicly listed companies covering the period 2020–2023. A fine-tuned SDG-BERT multi-label classification model is applied to extract and classify SDG-related content from top management communications, enabling sectoral, temporal, and cross-country comparison of SDG relevance. The results reveal a strong and persistent emphasis on SDG 12 (Responsible Consumption and Production) across both countries, alongside sector-specific variation and differing patterns of SDG diversity over time. South African firms exhibit greater variation in SDG emphasis across years, while Indian firms display more concentrated and stable SDG framing. Overall, the findings highlight systematic imbalances in SDG-related managerial communication and persistent underrepresentation of several social SDGs. The study contributes methodologically by demonstrating the value of validated AI-assisted longitudinal text analysis for large-scale SDG research and empirically by providing comparative insights into how corporate SDG narratives evolve in emerging market contexts. Full article

Malignant catarrhal fever (MCF) is a highly lethal viral disease of cattle that poses a persistent threat to livestock production in wildlife–livestock interface areas of Southern Africa. Despite its recognized clinical severity, the economic burden of the disease remains poorly quantified in South African production systems. This study assessed the long-term economic impact of malignant catarrhal fever on cattle production in Lephalale Municipality, Limpopo Province, South Africa, using a retrospective analysis covering the period from 2001 to 2021. The study combined confirmed case records, estimated mortalities, and region-specific production parameters to quantify both direct and indirect economic losses. Direct losses included mortality-related financial costs and the expenditure on treatment, while indirect losses encompassed reduced productivity, diminished milk yields, and associated declines in overall herd performance. The results show that MCF imposed substantial financial burdens on cattle producers, with mortality contributing to more than ninety percent of total losses. The total economic losses over the study period were substantial, amounting to approximately R 1.55 million, driven primarily by high mortality-related costs. Annual losses displayed considerable variability, reflecting the sporadic nature of the outbreaks and the fluctuations in the wildlife–livestock interactions. The spatial analysis revealed that most cases occur in wards situated adjacent to wildlife conservation areas, where cattle are exposed to virus-carrying wildebeest populations. Seasonal patterns indicated a higher disease occurrence during the spring and winter, aligning with established transmission dynamics. Although a gradual decline in both cases and associated losses was observed over the study period, episodic outbreaks continued to exert significant economic shocks on affected farming households. The findings reaffirm MCF as a persistent and high-impact constraint to cattle production in interface zones and highlight the need for improved surveillance, integrated land-use planning, and sustained investment in targeted disease control measures. Full article

Background: African animal trypanosomosis, caused by Trypanosoma vivax, remains a significant challenge to cattle health and productivity in regions where it is endemic. The development of vaccines against this parasite is particularly challenging due to its highly effective immune evasion mechanisms. Methods: An immunoproteomic approach was employed to identify T. vivax antigens through the immunocapture of parasite proteins using purified IgG from naturally infected sera. The objective of this strategy was to identify novel vaccine candidates, evaluated in a BALB/c murine model, aimed at promoting the induction of trypanotolerance. Results: An invariant surface glycoprotein (Uniprot code: F9WVM3, Tritryps code: TvY486_0045500), here designated TvISGAf, was selected based on its reported diagnostic relevance and its classification within the vivaxin antigen family. The protective potential of TvISGAf was evaluated in a murine model of T. vivax infection. Immunization with TvISGAf induced a robust antigen-specific humoral response, accompanied by a substantial cellular immune response. Following challenge, mice immunized with TvISGAf formulated with the ISPA adjuvant demonstrated enhanced control of body weight and hematocrit, and improved survival during the acute phase of infection in comparison to control group. Cytokine profiling revealed elevated levels of IFN-γ and TNF-α, accompanied by increased IL-10 production. Conclusions: Collectively, these findings demonstrate that TvISGAf formulated with ISPA confers partial protection during acute phase of infection, consistent with the induction of trypanotolerance. These results support its potential as a promising component of a multivalent vaccine strategy against T. vivax, and highlight the need for further evaluation prior to assessment in the bovine host. Full article

Fowl adenoviruses (FAdVs) represent a major threat to poultry health, with serotypes FAdV-1 and FAdV-4 causing adenoviral gizzard erosion (AGE) and hepatitis-hydropericardium syndrome (HHS), respectively. A wide variety of afflicted birds, including chicken, pigeon, and psittacine species, have been reported to carry aviadenoviruses. The disease is highly contagious and spreads rapidly between flocks and farms through vertical and horizontal transmission. In this study, we implemented a multi-stage computational drug-discovery pipeline to identify natural inhibitors of the viral fiber proteins for both FAdV-1 and FAdV-4. A curated library of 7523 natural compounds from the African Natural Products Database (ANPDB) and the South African Natural Compounds Database (SANCDB) was subjected to ADMET-based filtering, molecular docking, ADMET prediction, and 500 ns molecular dynamics simulations against four structural targets: Fiber-1 and Fiber-2 of FAdV-4, and the Short and Long Fibers of FAdV-1. Three ligands, ANPDB_6449 (−10.3 kcal/mol), ANPDB_2908 (−10.2 and −10.0 kcal/mol), and SANCDB_245 (−9.2 kcal/mol), consistently emerged as strong candidates across the entire computational workflow. While ANPDB_2908 demonstrated notable multi-target capability by binding to fiber proteins from both FAdV-1 and FAdV-4, ANPDB_6449 and SANCDB_245 exhibited strong serotype-specific potential, supported by stable interaction profiles and favorable drug-likeness characteristics. Together, these compounds highlight promising natural scaffolds for the development of targeted antiviral interventions against pathogenic FAdV serotypes. Full article

The SARS-CoV-2 papain-like protease (PL^pro) is an essential viral enzyme that promotes viral polyprotein processing while simultaneously suppressing the host innate immune response, which makes it a primary target for developing antiviral drugs. The present study employs a comprehensive approach integrating untargeted metabolomic profiling, in silico molecular docking and dynamics simulations, Molecular Mechanics Generalized Born Surface Area (MM-GBSA) energetic assessments, and biochemical enzyme assays. This integrated method aims to discover natural PL^pro inhibitors from two ethnomedicinal plants, Lippia javanica and Acorus calamus, which have long been utilized in African traditional medicine to treat respiratory diseases. Comprehensive metabolite profiling using untargeted Ultra-Performance Liquid Chromatography–Tandem Mass Spectrometry (UPLC-MS/MS) and Global Natural Products Social (GNPS) molecular networking revealed flavonoid glucuronides and phenylpropanoid derivatives as the major constituents in both plant species. In situ histochemical staining further offered spatial validation of phenolic- and lignin-associated tissues, supporting the phenolic-dominated molecular families detected by GNPS molecular networking. In silico evaluation of six selected compounds demonstrated spontaneous and thermodynamically favorable binding to PL^pro, with ΔG_bind values ranging from −5.63 to −6.43 kcal/mol. Catechin-7-glucoside emerged as the lead compound, establishing multiple hydrogen bond networks with Asp164, Gln269, Tyr264, and Asn267, supplemented by hydrophobic engagement with Pro247 and Pro248, and π-π stacking with the blocking loop 2 (BL2 loop). Molecular dynamics simulations confirmed the stability of the protein–ligand complexes. Biochemical enzyme assays confirmed concentration-dependent inhibition of PL^pro proteolytic and deubiquitinating activity by both crude plant extracts and isolated bioactive compounds. However, S-adenosyl-methionine showed comparatively high PL^pro proteolytic activity (IC₅₀ 5.872 µM) compared to catechin-7-glucoside, with an IC₅₀ of 7.493 µM, exhibiting efficacy similar to the reference inhibitor GRL0617. Both the extracts of L. javanica and A. calamus have shown significant inhibitory activity while maintaining cell viability in Human embryonic kidney 293T cell (HEK293T) culture models, indicating a favorable safety profile of the tested concentrations. Based on these results, catechin-based polyphenols and phenylpropanoid derivatives appear as promising lead compounds for the development of PL^pro inhibitors. To progress toward therapeutic use, further work is necessary in pharmacokinetics, structural optimization, and antiviral validation in cell models. Full article

Type 2 diabetes mellitus (T2DM) remains a global health challenge, necessitating novel therapeutic and dietary strategies. This study optimized hydroalcoholic extraction parameters to maximize α-amylase inhibitory activity from five African medicinal plants: Combretum glutinosum (CG), Ziziphus mauritiana (ZM), Gymnosporia senegalensis (GS), Boscia senegalensis (BS), and Citrullus colocynthis (CC). A central composite design (CCD) modeled the effects of the liquid-to-solid (L/S) ratio (5–15 mL/g) and ethanol concentration (0–100%, v/v), identifying optimal conditions at low L/S ratios (5 mL/g) and moderate-to-high ethanol concentrations (40–100%) for GS, ZM, and CG, where inhibition levels exceeded 80–98% of α-amylase activity. Extracts from CG, ZM, and GS showed the strongest inhibition (IC₅₀ values of 3.67, 9.8, and 2.25 mg/mL, respectively). Antioxidant capacities, evaluated by DPPH and FRAP assays, correlated strongly with total phenolic content (TPC), with ZM exhibiting superior DPPH (IC₅₀ = 1.94 ± 0.16 mg/mL) and FRAP (IC₅₀ = 4.34 ± 0.52 mg/mL) activities. Incorporation of optimized plant powders (3%, w/v) into bread dough significantly influenced textural and colorimetric properties. Mixture design analysis revealed that CG-rich formulations (>2%) yielding hardness exceed 6 N, while ZM–GS blends maintain 3 N, offering targeted firmness control. The addition of medicinal plants significantly increased the total phenolics content by 60% of doughs and thus caused a significant improvement in antioxidant activities. These functional enrichments suggest potential for developing hypoglycemic bakery products with improved sensory attributes. This integrative approach combining extraction optimization and food formulation offers promising avenues for natural antidiabetic agents and functional food development. Full article

Contamination of agricultural products such as maize by fungi is a significant concern worldwide, as it can compromise food safety and quality. In recent years, the use of microorganisms as natural food preservatives has gained interest. Probiotic lactic acid bacteria (LAB) and their metabolites are considered a promising strategy to reduce fungal growth and limit other food contaminants. This study aimed to characterize, screen and compare the probiotic properties and antifungal activity of LAB of maize origin. A total of 23 LAB isolates obtained from untreated maize grains were identified through 16S rRNA gene sequencing as Weissella viridenscens (34.7%), Pediococcus pentosaceus (34.7%), Enterococcus durans (17.4%), Leuconostoc citreum (9%), and Enterococcus faecium (4.3%). All isolates demonstrated acid, phenol, and bile salt tolerance; surface hydrophobicity; and antagonistic activity against selected bacterial foodborne pathogens. Notably, Enterococcus sp. showed the strongest inhibitory activity against Escherichia coli ATCC 5211 (21 mm inhibition zone) and Staphylococcus aureus (17 mm inhibition zone), whereas Pediococcus sp. exhibited the highest antagonistic effect against Listeria monocytogenes (18.7 mm inhibition zone). Furthermore, E. durans and P. pentosaceus demonstrated the strongest antifungal activity, effectively inhibiting the growth of Alternaria tenuissima (F22FR) and Fusarium oxysporum (F44FR), respectively. Overall, all the LAB strains isolated from this study showed considerable potential for use in the food industry as probiotics, starter cultures for functional food fermentations, bio-preservatives and biocontrol agents against toxigenic fungi and pathogenic bacteria, with E. durans standing out for its exceptional performance. Future research will explore the ability of these isolates and/or their enzymes to degrade mycotoxins commonly found in maize, a staple food in many African countries. Full article

The Temane gas field, the first producing natural gas field in Mozambique, remains a key supplier to southern Mozambique and the South African market. In recent years, however, the field has experienced an accelerated production decline, raising concerns regarding its long-term supply sustainability. Between 2020 and 2024, gas production decreased by approximately 25%, motivating a comprehensive reserve assessment to quantify the remaining potential and support informed reservoir management. This study applied three modern rate transient analysis (RTA) methods (Blasingame, normalized rate–cumulative, and flowing material balance) to twenty years of daily production data from thirteen producing wells across three reservoirs (G-9A, G-9B, and TEast) on a per-well basis. The RTA methods yielded consistent estimates, indicating an original gas-in-place value of 1576.38 Bscf, a remaining gas-in-place value of 503.37 Bscf, an estimated ultimate recovery of 1405.25 Bscf, and a field-average recovery factor of 76.35%. Reservoir-level recovery factors are estimated at 79% for G-9A, 74.92% for G-9B, and 58.01% for TEast. Despite the high depletion level, the magnitude of the observed production decline is not fully explained by reservoir exhaustion alone, suggesting that the field retains significant remaining recovery potential. Full article