Search Results (339)

Cervical cancer is more common in Sub-Saharan Africa (SSA) compared to developed countries, with persistent genital high-risk HPV (HR-HPV) infection identified as the cause. However, other factors contributing to this gap remain unclear. This review explores the potential role of cervicovaginal microbiota (CVM) in genital HPV infection and cervical cancer development among women in SSA. Many women of African descent, including those from SSA, lack lactobacilli dominance in their CVM, which is considered a biomarker of cervicovaginal health. Published literature has associated Lactobacillus-dominated CVM with a lower risk of HPV infection and cervical cancer. The converse is true for women with high diversity non-Lactobacillus-dominated CVM and bacterial vaginosis, the most common form of vaginal disorder. However, findings on the relationship between specific bacterial abundance and cervical disease severity are inconsistent and inconclusive due to differences in study design, study population, sampling, and potential confounders. Thus, there is a need to form consensus to advance research on CVM and HPV-associated cervical disease. Despite the exact mechanisms by which CVM influence HR-HPV persistence and cervical carcinogenesis being unknown, the backbone of the mechanisms appears to be mediated in part by the following: cervicovaginal dysbiosis, elevated vaginal pH, high ratio of L-to-D-lactic acid, cohesive biofilm formation, chronic inflammation, and immune dysregulation. Consequently, these promote cellular proliferation, genetic instability, and evasion of immune surveillance. This review calls for larger, prospective studies to unravel causal links, identify protective features, and integrate CVM interventions into HPV and cervical cancer prevention strategies in SSA. Full article

Background: Environmental changes impact bat–human interactions, heightening concerns of pathogen spillover and highlighting the need to understand human–bat interactions in the context of ecosystems. The objective of this study was to assess factors associated with human contact with bats in communities living near bat roosts in Northern Tanzania. Methods: A cross-sectional survey was used to investigate the factors associated with human contact with bats. Utilizing a standardized questionnaire administered through face-to-face interviews, relevant data were collected from respondents living in or near regions characterized by high bat density. Descriptive analyses followed by bivariate and multivariate analyses were performed to assess the association between the investigated factors and the outcome variable of interest, contact with bats. Results: Data were collected from 325 respondents. Of the respondents, 57.5% (187/325) reported bat contact, and only 4% believed bats can transmit rabies. The following factors were significantly associated with human–bat contact: being unaware that bats can transmit diseases like rabies (AOR = 8.63, CI = 1.04, 71.43, p = 0.045), feeling safe to handle bats with bare hands (AOR = 3.47, CI = 1.71, 7.05, p < 0.001), not washing hands thoroughly after bat bite or scratch (AOR = 2.43, CI = 1.29, 4.59, p = 0.006), using water from ponds, rivers or wells (AOR = 5.58, CI = 3.17, 9.79, p <0.001), age > 45 years (AOR = 1.77, CI = 1.0, 3.14, p = 0.047) and a low level of education (AOR = 5.86, CI = 2.97, 11.57, p <0.001). Conclusion: The study findings highlight the key factors to be targeted when developing strategies aimed at improving the community’s knowledge of the potential risks of zoonotic infectious diseases associated with bats and reducing the likelihood of human–bat contact and the related public health risks in communities living near bat roosting sites in Tanzania. Full article

It has been argued that domestication explains the ability of domestic animals to use human cues, but similar abilities exist in wild animals repeatedly exposed to humans. Little is known on the importance of the developmental stage of this exposure for developing such abilities. Orphancy and subsequent hand-rearing constitute a quasi-experimental situation for investigating this question. Cheetahs (Acinonyx jubatus) are interesting as they present a two-step development, spending their first two months of life in a den with occasional visits from the mother, and then accompanying their mother outdoors. Mother loss may occur at any of these stages, and the orphaned cheetahs are then taken under human care. We tested the importance of the stage of development on their long-term perception of humans by comparing the reactions of adult wild-born cheetahs, orphaned at “den-age” (Early-Orphaned, 0–2 months) or at a later stage (Late-Orphaned, 2–6 months), to motionless humans (familiar vs. unfamiliar). The results showed that Early-Orphaned, but not Late-Orphaned cheetahs, produced affiliative calls (purrs) towards humans and discriminated familiar and unfamiliar humans. Taken together, these results suggest that the timing in which an emotional bond is created with the primary caregiver (humans in the case of Early-Orphaned cheetahs and the mother in the case of Late-Orphaned cheetahs) is crucial in determining the reaction towards the species of the early caregiver throughout life. Full article

Cystic fibrosis (CF) is a rare autosomal recessive disease most commonly affecting the Caucasian population. CF diagnosis can be a challenge due to the large spectrum of pathogenic variants in the CFTR gene and the effects of complex alleles. Next-generation sequencing has improved our understanding of the contribution of these complex alleles to the wide spectrum of CF clinical symptoms and to the response to medications. Herein, we studied nine CF patients from six unrelated families carrying the complex allele p.[Ile148Thr;Ile1023_Val1024del] with a frequency of 0.18%. All patients were from Central Mexico. This complex allele was found in trans with Class I and II pathogenic variants such as p.(Phe508del), and p.(Phe1078Profs*77)]. A targeted search of a dataset of 2217 exomes from healthy individuals revealed that eight individuals (0.18%) carried the p.(Ile148Thr) variant, but only one (0.022%), who was also born in Central Mexico, was a carrier of the complex allele. These findings show an enrichment of this p.[Ile148Thr;Ile1023_Val1024del] complex allele in Mexican CF patients in this region of Mexico. Finally, protein modeling revealed that this complex allele disrupts the secondary structure of the CFTR protein and might alter the ion flow. Full article

The latest Intergovernmental Panel on Climate Change Sixth Assessment Report urgently calls for sweeping action to mitigate the unprecedented impacts of climate change. The path to a carbon-neutral future is intricate, necessitating a multi-faceted approach that integrates decarbonization, defossilization, and energy/resource efficiency. Power-to-X (PtX) stands as a technological linchpin, converting renewable electricity into a range of sustainable products, from fuels to chemicals. However, its full potential is intrinsically tied to the availability of sustainable carbon sources. This paper evaluates the various avenues for carbon sourcing for PtX: direct air capture (DAC), biogenic carbon, and Long-cycle Industrial Carbon. DAC, although promising for the long term, has limitations in scalability and land requirements. Industrial long-cycle carbon capture technology is improving but requires a thorough Life Cycle Assessment for evaluating its sustainability. This study examines the environmental impacts, scalability, and logistical considerations of each carbon source. Biogenic carbon offers a near-term solution, and its various forms could simplify transportation logistics. An analysis of gasification processes, syngas cleaning, and hydrogen integration was conducted to assess the technical viability of these carbon sources in PtX applications. The results show that torrefied biomass pellets, after a thorough technical assessment, present a globally feasible and sustainable carbon carrier, setting the stage for industry standardization and easier global transportation. Syngas produced through the gasification of the pellets complemented by green hydrogen can be utilized in Fischer–Tropsch, methanol synthesis, and methanation, allowing PtX to synthesize practically any type of organic compounds in a hybrid Biomass–PtX (HBPtX) process. This study provides key insights for industries and policymakers by demonstrating the technical feasibility and sustainability of torrefied biomass as a carbon carrier, thereby supporting the development of comprehensive climate mitigation strategies. Full article

The application of hydrogeophysical techniques to delineating aquifers was conducted in De Aar, the eastern part of the Karoo region, Northern Cape, South Africa. Previously, recharge estimations in this region assumed a uniform aquifer type, overlooking the presence of diverse aquifer systems. This study identified both unconfined and confined aquifers to improve recharge potential assessments. Vertical electrical resistivity sounding (VES) and ground telluric methods were applied. Six VES stations and eleven profiles were measured using a 1D Wenner array configuration. The VES data, processed with IPI2win software, generated a 2D subsurface model. In contrast, the telluric data were analyzed using an automated algorithm to create a 2D profile. The electric potential difference curve was interpreted in comparison with lithological cross-sections. The VES results revealed three to four distinct layers of low-resistivity (0.9–8.1 Ωm), moderate-resistivity (22.4–125 Ωm), and high-resistivity (68–177 Ωm) values, indicating three lithological formations. The telluric data suggested that shallow groundwater boreholes were located in areas with groundwater levels above 50 m. These findings, which matched the lithological data, pointed to a double-layer aquifer system, suggesting that recharge estimates should be carried out to different aquifer layers. The study demonstrated how hydrogeophysical methods can effectively delineate aquifer systems and enhance the identification of recharge areas. Full article

This study compared the effects of three supplementary diets—egg yolk, Artemia, and commercial pellets with 48% crude protein—on the growth performance and survival rate of redbreast tilapia (Coptodon rendalli) under intensive culture conditions at the Kamutjonga Inland Fisheries Institute in the Kavango East region of Namibia. The study was conducted from December 2023 to January 2024 using a complete randomized design replicated thrice. Results showed that fish fed with commercial pellets exhibited the highest specific growth rate (1.39 ± 0.80%) compared to egg yolk (0.94 ± 0.54%) and Artemia (0.33 ± 0.19%). Commercial pellets also had the best survival rate (76.19 ± 43.099), compared to egg yolk and Artemia (70.47 ± 40.69; 33 ± 19.05), respectively. However, egg yolk had the best feed conversion ratio (0.20 ± 0.05) compared to the commercial pellets (0.22 ± 0.04) and Artemia (0.26 ± 0.07). Critical water quality parameters were maintained within acceptable survival ranges for C. rendalli across all treatments. These findings highlight the importance of dietary protein content in optimizing the growth and survival of C. rendalli under intensive culture conditions and provide insights for effective feeding strategies. However, commercial pellets are expensive and inaccessible to small-scale fish farmers. As an alternative, egg yolk emerged as a viable and affordable feed option, promoting fish growth and supporting the establishment of small-scale farming practices in the region. Full article

This paper explores the mathematical dynamics of consumer spending during a financial crisis using opponent process theory (OPT). Traditionally applied in psychology, OPT explains how initial emotional responses are followed by counteracting reactions to restore equilibrium. This study models the short-term boost in consumer spending and subsequent economic adjustments. Utilizing differential equations to represent these processes, this paper provides insights into the interplay between immediate policy effects and longer-term economic consequences. We focus on the United States (US) response to the 2008 Global Financial Crisis in this study. Results show evidence of diminishing response from prolonged stimuli due to demand saturation, resource allocation inefficiencies, and agent adaptation. Monetary stimuli may inflate debt/prices, outweighing benefits, and structural issues persist despite stimuli. Confidence and expectations impact response because perceived ineffectiveness weakens impact over time. Thus, while stimuli can initially boost activity, their sustained impact demands careful consideration of economic dynamics and agents’ responses. Full article

Introduction: The WHO Measles and Rubella Strategic Framework 2021–2030 within the Immunization Agenda 2030 includes both measles and rubella elimination goals and provides guidance to countries for planning and implementing the measles and rubella elimination strategies. Namibia has been implementing measles elimination strategies since 1997. Methods: We reviewed and described the implementation of measles and rubella elimination strategies and the programmatic and epidemiological situation in Namibia during 2000–2023. Namibia introduced a rubella-containing vaccine (RCV) in 2016 as a combined measles–rubella (MR) vaccine using a MR catch-up campaign, targeting a wide age range based on detailed analysis and triangulation of multiple key data sources including MR vaccination coverage, MR case-based surveillance, detailed measles outbreak investigations, and serosurveys. Results: In 2020, estimated MCV1 coverage in Namibia reached 90% and has been sustained at 91% in 2021 and 2022. MCV2 was introduced in 2016, and the estimated MCV2 coverage has steadily increased to 79% in 2022. Following the MCV2 introduction and the implementation of the wide age range MR catch-up campaign in 2016, annual measles and rubella incidence decreased substantially. During 2017–2023, the period following the implementation of the catch-up MR vaccination SIA in 2016, average annual measles incidence per million population in Namibia decreased by 97% from the average during 2010–2016. Similarly, the average annual rubella incidence decreased by 95% from 2010–2016 to 2017–2023. Discussion: Successful implementation of the 2016 wide age range campaign and maintaining high routine immunization coverage likely led to the significant reduction in measles and rubella incidence in Namibia. To sustain the reduction in measles and rubella incidence and attain the elimination targets, Namibia needs to attain and maintain high routine immunization coverage with both doses of the MR vaccine and implement timely and high-quality periodic MR follow-up SIAs. High-quality elimination-standard measles and rubella surveillance will help guide strategies and serve as the basis for the eventual verification of measles and rubella elimination in Namibia according to the WHO-recommended framework. Full article

This empirical study investigated the associations between psychological well-being, job satisfaction, trust in supervisor, and job performance. Data were collected from 277 company employees in Bahrain through online questionnaires and analyzed using structural equation modeling (SEM). The purpose of the study is to examine the relationships between psychological well-being, job satisfaction, trust in supervisor, and job performance through the use of a theoretical framework that synthesizes prominent models in the field of organizational psychology. The research findings indicate a positive influence of psychological well-being on both job satisfaction and job performance. Notably, job satisfaction plays a mediating role in the relationship between psychological well-being and job performance. The study contributes to the existing body of knowledge by offering an integrated approach to examining the intricate connections between psychological well-being, job satisfaction, trust in supervisor, and job performance, which all are crucial for creating a sustainable workplace environment and outcomes. Practical implications highlight the need for organizations to prioritize employee psychological well-being through initiatives such as wellness programs and supportive work environments, as these initiatives directly influence job satisfaction and performance. Job satisfaction acts as a significant mediator, emphasizing the importance of fair compensation, recognition, and professional development in enhancing job satisfaction. Full article

Since the early 1970s, the study of Black–Scholes (BS) partial differential equations (PDEs) under the Efficient Market Hypothesis (EMH) has been a subject of active research in financial engineering. It has now become obvious, even to casual observers, that the classical BS models derived under the EMH framework fail to account for a number of realistic price evolutions in real-time market data. An alternative approach to the EMH framework is the Fractal Market Hypothesis (FMH), which proposes better and clearer explanations of market behaviours during unfavourable market conditions. The FMH involves non-local derivatives and integral operators, as well as fractional stochastic processes, which provide better tools for explaining the dynamics of evolving market anomalies, something that classical BS models may fail to explain. In this work, using the FMH, we derive a time-fractional Black–Scholes partial differential equation (tfBS-PDE) and then transform it into a heat equation, which allows for ease of implementing a high-order numerical scheme for solving it. Furthermore, the stability and convergence properties of the numerical scheme are discussed, and overall techniques are applied to pricing European put option problems. Full article

The utilization of an agricultural waste product known as palm kernel shells (PKS) combined with fine laterites (from basalt in Bangangté, West Cameroon) to produce low-cost and innovative materials with good bearing capacities for road pavement was investigated. Fine laterites from two soil profiles (BL31 and BL32) and made up of kaolinite, hematite, goethite, gibbsite, anatase, ilmenite and magnetite minerals were partially replaced with PKS at 15%, 25%, 35%, and 45% by weight. Physical and mechanical tests, including particle size distribution, Atterberg limits, unsoaked and soaked California Bearing Ratio (UCBR and SCBR), unconfined compressive strength (UCS), and tensile strength (Rt), were performed on the different mixtures. After the addition of PKS, a decrease in fine particle content (77 to 38%), liquidity limit (LL: 72 to 61%), plasticity index (PI: 30 to 19%), maximum dry density (MDD: 1.685 to 1.29 t/m³), and optimum moisture content (OMC: 27.5 to 24.0%) was noticed. Additionally, there was an increase in UCBR (16–72%), SCBR (14–66%), UCS (1.07–7.67 MPa), and Rt (2.24–9.71 MPa). This allows new materials suitable for the construction of base layers for low trafficked roads (T1–T2), as well as sub-base and base layers for high trafficked roads (T3), to be obtained. This newly formed material can be recommended locally for road construction works, though more in-depth studies are required. Full article

(1) Background: Gentamicin is known to be nephrotoxic and ototoxic. Although gentamicin dosage guidelines have been established for preterm and term neonates, reports do show attainment of recommended peak concentrations but toxic gentamicin concentrations are common in this age group. (2) Methods: This was a prospective, observational study conducted in Namibia with 52 neonates. A dose of 5 mg/kg gentamicin was administered over 3–5 s every 24 h in combination with benzylpenicillin 100,000 IU/kg/12 h or ampicillin 50 mg/kg/8 h. Two blood samples were collected from each participant using a truncated pharmacokinetic sampling schedule. (3) Results: The one-compartment linear pharmacokinetic model best described the data. Birthweight, postnatal age, and white blood cell count were predictive of clearance (CL), while birthweight was predictive of volume (V). For the typical neonate (median weight 1.57 kg, median postnatal age 4 days (0.011 years), median log-transformed WBC of 2.39), predicted CL and V were 0.069 L/h and 0.417 L, respectively—similar to literature values. Simulated gentamicin concentrations varied with respect to postnatal age and bodyweight. (4) Conclusions: A 5 mg/kg/24 h dosage regimen yielded simulated gentamicin concentrations with respect to age and birthweight similar to those previously reported in the literature to be safe and efficacious, confirming its appropriateness. Full article

Integrating artificial intelligence (AI) in open and distance learning (ODL) necessitates comprehensive frameworks to evaluate its educational implications. Existing models lack a robust multilayered analysis of AI’s impact on educational outcomes in ODL. This study introduces a Multilayered Process Framework designed to predict academic performance in ODL and enhance inclusivity, aligning with UNESCO’s 2030 educational goals. The current research employed structural equation modelling (SEM) to analyse the impact of AI adoption, focusing on the initial layers of the process framework. Preliminary validation of the SEM framework showed a good model fit, with a Chi-square/df ratio of 2.34, Root Mean Square Error of Approximation (RMSEA) of 0.045, and Comparative Fit Index (CFI) of 0.97, indicating the model’s effectiveness in capturing the complexities of AI impacts on student outcomes. This framework provides a structured, multilayered approach to understanding AI’s role in education, facilitating the development of equitable and accessible AI-driven educational technologies. It lays the foundational work for expanding research into predictive analytics with a support vector machine (SVM), aiming to universalise quality education and ensure global educational equity. This study highlights the practical implications for integrating AI in educational settings and suggests future research directions to enhance the adaptability and effectiveness of AI-driven educational interventions. Full article

This study investigates the performance of YOLOv8, a Convolutional Neural Network (CNN) architecture, for multi-crop classification in a mixed farm with Unmanned Aerial Vehicle (UAV) imageries. Emphasizing hyperparameter optimization, specifically batch size, the study’s primary objective is to refine the model’s batch size for improved accuracy and efficiency in crop detection and classification. Using the Google Colaboratory platform, the YOLOv8 model was trained over various batch sizes (10, 20, 30, 40, 50, 60, 70, 80, and 90) to automatically identify the five different classes (sugarcane, banana trees, spinach, pepper, and weeds) present on the UAV images. The performance of the model was assessed using classification accuracy, precision, and recall with the aim of identifying the optimal batch size. The results indicate a substantial improvement in classifier performance from batch sizes of 10 up to 60, while significant dips and peaks were recorded at batch sizes 70 to 90. Based on the analysis of the obtained results, Batch size 60 emerged with the best overall performance for automatic crop detection and classification. Although the F1 score was moderate, the combination of high accuracy, precision, and recall makes it the most balanced option. However, Batch Size 80 also shows very high precision (98%) and balanced recall (84%), which is suitable if the primary focus is on achieving high precision. The findings demonstrate the robustness of YOLOv8 for automatic crop identification and classification in a mixed crop farm while highlighting the significant impact of tuning to the appropriate batch size on the model’s overall performance. Full article