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Computational aspects of likelihood-based inference for the univariate generalized hyperbolic distribution
Van Wyk, Arnold; Azzalini, Adelchi; Bekker, Andriette, 1958- (Taylor and Francis, 2026)
The generalized hyperbolic distribution is among the more often adopted parametric families in a wide range of application areas, thanks to its high flexibility as the parameters vary and also to a plausible stochastic mechanism for its genesis. This high flexibility comes at some cost, however, namely the frequent difficulty of estimating its parameters due to the presence of flat areas of the log-likelihood function, so that selected points of the parameter space, while very distant, can be essentially equivalent as for data fitting. This phenomenon affects not only maximum likelihood estimation, but Bayesian methods too, since the target function is little affected by the introduction of a prior distribution. Our interest focuses in fact on maximum likelihood estimation of the Generalized hyperbolic distribution, working in the univariate case. This paper improves upon currently employed computational techniques by presenting an alternative proposal that works effectively in reaching the global maximum of the likelihood function. The paper further illustrates the above mentioned problems in a number of cases, using both simulated and real data.
Computational and molecular dynamics insights into the antithrombotic mechanism of triterpenes derived from Melaleuca bracteata var. Revolution Gold (Myrtaceae)
Appiah-Kubi, Patrick; Osunsanmi, Foluso Oluwagbemiga; Opoku, Andrew Rowland; Singh, Ashona (MDPI, 2026)
BACKGROUND/OBJECTIVES : Thrombin, a serine protease central to coagulation and platelet activation, remains an important target for the development of safer and more effective antithrombotic agents. Naturally derived pentacyclic triterpenoids, such as betulinic acid and its acetylated derivatives, 3β-acetoxybetulinic acid, exhibit promising antiplatelet aggregation activity in validated in vitro and ex vivo assays; however, the molecular determinants underlying their direct thrombin inhibition remain unexplored. RESULTS : Docking and MM/GBSA analyses revealed that Baa exhibits the strongest binding affinity (ΔG = −29.58 ± 2.97 kcal/mol), exceeding those of Ba (−20.94 ± 5.81 kcal/mol) and Asp (−18.87 ± 4.18 kcal/mol). Baa forms a highly persistent hydrogen bond with Trp96 (95.5% occupancy) and extensive hydrophobic contacts with Trp215, Leu99, Ile174, and Tyr60A residues defining thrombin’s aryl-binding pocket. MD trajectories demonstrated that Baa binding reduced solvent-accessible surface area (SASA) and residue fluctuations, indicating enhanced structural compaction and stability. In contrast, Ba exhibited weaker, transient hydrogen bonding, while Asp bound primarily near the catalytic triad. The triterpenes exhibit limited oral bioavailability, free PAINS alerts, favourable permeability and metabolic stability. CONCLUSIONS : Acetylation at C-3 (acetoxy substitution) substantially enhances thrombin binding via cooperative hydrogen bonding and van der Waals stabilisation, explaining the superior experimental inhibitory potency of Baa. These findings provide a mechanistic framework for structure-guided optimisation of triterpenoid-based thrombin inhibitors and support their further experimental development. Methods: In this study, molecular docking, molecular dynamics (MD) simulations (400 ns), and MM/GBSA free energy analyses were employed to elucidate the binding mechanisms of 3β-acetoxybetulinic acid (Baa), betulinic acid (Ba), and aspirin (Asp) within the thrombin receptor active site. The simulations were explicitly grounded in previously reported chromogenic antithrombin assays and platelet aggregation studies and were designed to mechanistically rationalise the experimentally observed inhibitory potency.
Complementary and alternative management of female infertility in African women : a systematic review protocol
Armah, Deborah; Kyei, Josephine M.; Van der Wath, Anna Elizabeth; Ansong-Aggrey, Samuel Kwabena; Azanku, Believe; Naab, Florence (Sage, 2026-01-14)
INTRODUCTION : Although African women constitute the majority of the continent's population and play a central role in economic development, their reproductive health needs remain overlooked. Infertility is often regarded as a tragedy, carrying profound psychosocial consequences. The resulting stress and societal pressure undermine women's well-being and drive many to pursue alternative treatment options in their search for motherhood. This systematic review aims to map the existing evidence on complementary approaches to the management of female infertility in Africa. METHODS : A systematic review was conducted through searching English databases, including PubMed, Scopus, CINAHL, Google Scholar, EBSCOhost, Medline, ProQuest, and ScienceDirect. The screening of titles, abstracts, and full texts was conducted using searches such as CAM/therapy, women, and infertility. All studies published in peer-reviewed journals from 2020 to 2025 which examined women's needs in the field of CAM use were included in the review. Out of the 300 records reviewed, 30 studies were included in the final review. RESULTS : The 30 studies reviewed revealed widespread use of complementary approaches to infertility management among African women. These practices were shaped by sociocultural beliefs, psychosocial pressures, accessibility, and perceived limitations of conventional care. Overall, the findings indicate a strong tendency toward pluralistic health-seeking behaviors in the management of female infertility across African settings. CONCLUSION : Women experiencing infertility frequently seek treatments beyond conventional medicine, including herbal remedies, prayers, plant-based products, lifestyle and dietary changes, allopathic therapies, indigenous counselling, and acupuncture in their pursuit of pregnancy.
Comparative study of biogenic iron oxide nanoparticles from various extracts of Punica granatum and their efficient application for removal of BTEX
Enemuo, Ngozi; Daramola, Michael Olawale; Richards, Heidi (Elsevier, 2026-03)
This study investigated the potential of Punica granatum-mediated iron oxide nanoparticles (FeNPs) in the adsorptive removal of BTEX from wastewater. To gain insight into achieving optimum BTEX removal, the study highlighted the role of phytochemical composition in determining the features of the resulting nanoparticles and, subsequently, the FeNPs' adsorption capacity. It established the Punica granatum part that generates ideal FeNPs with optimum performance in BTEX adsorption. Three Punica granatum parts, the leaves, peels, and seeds, were utilized for the biogenic synthesis of the FeNPs, and the features and performance of the FeNPs in BTEX adsorptive removal were analyzed. It was found that the FeNPs from various Punica granatum parts, namely FeNPs-leaves, FeNPs-peels, and FeNPs-seeds, exhibited distinct features due to the unique phytochemical composition of these parts, as indicated by their total phenolic content (TPC) measurement and GC–MS analysis. The XRD result showed that bio-reduction using the leaves extract yielded magnetite, while bluish-black maghemite and yellowish-brown maghemite were obtained from the peels and seeds extracts, respectively. The three FeNPs also have different specific surface areas, at 8.61 m²/g, 48.45 m²/g, and 35.40 m²/g for FeNPs-leaves, FeNPs-peels, and FeNPs-seeds, respectively. The properties of the FeNPs influenced their BTEX adsorption capacity, with the FeNPs-peels (48.45 m²/g) and FeNPs-seeds (35.40 m²/g) exhibiting higher specific surface area than the FeNPs-leaves (8.61 m²/g), which reflected in the higher BTEX adsorption capacity obtained for the FeNPs-peels and FeNPs-seeds. The BTEX adsorption on the FeNPs mainly occurs through chemisorption in a monolayer surface, as indicated by the adsorption data fitting in pseudo-second-order and the Langmuir isotherm model. HIGHLIGHTS • Pomegranate leaves, peels, and seeds have different concentration and composition of phytochemicals. • Bio-reduction of FeCl3 using extracts of the three pomegranate parts produced FeNPs with distinct features. • The produced FeNPs exhibited varying tendencies for the adsorptive removal of BTEX in wastewater. • The peels extract yields FeNPs with the highest BTEX adsorption capacity. • The pseudo-second-order and Langmuir isotherm models describe the processes involved in BTEX adsorption.
Comparative proximate analysis and nutrient labelling compliance of cow milk and plant-based milk alternatives : implications for consumer choice and food policy
Pieterse, Elaine; Pretorius, Beulah; Schonfeldt, H.C. (Hettie Carina) (Elsevier, 2026-02)
This study compared the nutritional composition of cow milk and plant-based milk alternatives (PBMAs) available in South African retail markets and assessed nutrient labelling compliance. Proximate and mineral analysis was conducted on 60 PBMA samples (soy, almond, oat, rice, coconut) and 39 cow milk samples using standardised analytical methods. Results demonstrated significant nutritional differences between product categories (p < 0.05). Cow milk demonstrated significantly higher nutrient density, particularly for protein and key bone-building minerals including calcium, phosphorous, and zinc. Conversely, PBMAs showed higher iron, copper, and manganese levels, though bioavailability may be compromised by antinutrients. Labelling non-compliance was identified for calcium and dietary fibre overreporting for PBMAs, and sodium underreporting across both categories. These findings indicate that PBMAs are not nutritionally equivalent to cow milk and highlight the need for improved regulatory oversight of nutritional labelling to prevent consumer misinformation. HIGHLIGHTS • First comprehensive proximate analysis of South African retail PBMAs. • PBMA labels overreported calcium and dietary fibre, and underreported sodium. • A typical 200 ml serving of PBMAs provides less than 0.2 g fibre. • Cow milk maintains optimal Ca:P ratios (1.09–1.44) versus imbalanced ratios in PBMAs.