Scientific African最新文献

{"title":"Allopurinol as cardioprotective agent in chronic coronary syndrome: In silico evaluation of its potential as Keap1/Nrf2 modulator","authors":"Kannan O. Ahmed ,&nbsp;Mohammed A. Almogaddam ,&nbsp;Hagar M. Mohamed ,&nbsp;Bayan E. Ainousah ,&nbsp;Gamal A. Mohamed ,&nbsp;Sabrin R. M. Ibrahim ,&nbsp;Nawal A. Alharbi ,&nbsp;Toga K. Mohamed ,&nbsp;Bashir A. Yousef ,&nbsp;Khalid Al Balushi ,&nbsp;Abdulrahim A. Alzain","doi":"10.1016/j.sciaf.2025.e02743","DOIUrl":"10.1016/j.sciaf.2025.e02743","url":null,"abstract":"<div><div>Chronic coronary syndrome (CCS), a leading cause of global morbidity and mortality, is closely linked to oxidative stress and hyperuricemia. Despite mixed clinical outcomes, allopurinol, a xanthine oxidase inhibitor, has shown potential cardiovascular benefits beyond urate reduction. This study investigates allopurinol’s molecular interactions with the Keap1/Nrf2 pathway, a key regulator of antioxidant responses, using computational approaches. Molecular docking (Glide XP, Schrödinger Maestro) and dynamics simulations (Desmond, OPLS4 force field) analyzed allopurinol’s binding to the Keap1 kelch domain, comparing it to a co-crystallized ligand and inhibitor KI696. Docking revealed moderate affinity for allopurinol (−5.372 kcal/mol), driven by hydrogen bonds (ARG415, SER555) and hydrophobic interactions. Molecular dynamics simulations (100 ns) demonstrated stable binding, with an average RMSD of 3.3 Å. Persistent interactions, including hydrogen bonds with ARG415 and SER555, highlighted allopurinol’s dynamic stability. These findings propose allopurinol as a Keap1 inhibitor, potentially mitigating oxidative stress in CCS. Further experimental is recommended to validate allopurinol’s role in CCS management and bridging computational evidence with clinical application.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"28 ","pages":"Article e02743"},"PeriodicalIF":2.7,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143923604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the influence of organisational resources and learning capabilities on the performance of small, micro, and medium enterprises (SMMEs) in Ghana","authors":"Johnson Yeboah,&nbsp;Luther-King Junior Zogli","doi":"10.1016/j.sciaf.2025.e02740","DOIUrl":"10.1016/j.sciaf.2025.e02740","url":null,"abstract":"<div><div>This study examine the influence of Organizational Learning (OL) and organisational resources on the performance of Small, Micro, and Medium Enterprises (SMMEs) in Ghana's Western Region. Using a quantitative approach within a positivist framework, data were collected from 389 SMME owners and managers via a structured questionnaire distributed by convenience sampling. Of the 370 responses received, 350 were analysed using SPSS (version 27). The results revealed a significant positive relationship between OL and SMME performance. The findings indicate that higher perceptions of OL dimensions, such as continuous learning and resource exploitation, correlate with improved performance. This research highlights the critical role of ongoing learning and resource management for SMME growth and underscores the need to address institutional limitations. Managers are encouraged to engage in continuous education, proactive information gathering, and evaluation to enhance their firm's performance.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"28 ","pages":"Article e02740"},"PeriodicalIF":2.7,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143929587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymmetric dependence between commodity prices and selected macroeconomic variables in Ghana","authors":"Samuel Duku Yeboah,&nbsp;Michael Provide Fumey,&nbsp;Stephen Antwi Winful,&nbsp;Isaac Christopher Otoo,&nbsp;Peterson Owusu Junior","doi":"10.1016/j.sciaf.2025.e02739","DOIUrl":"10.1016/j.sciaf.2025.e02739","url":null,"abstract":"<div><div>The nexus between commodity prices (CDP) and exchange rates (EXE) is critical, particularly for a commodity-exporting nation like Ghana. This study investigates the asymmetric dependence between commodity prices (Cocoa, Crude Oil, Gold, Petrol, and Diesel) inflation and exchange rates in Ghana. The study employed monthly frequency data from 2003 to 2023 on commodity prices, inflation, and exchange rates. The research unveils fresh insights into this complex nexus by employing a quantile-on-quantile estimation. The findings challenge the conventional understanding of a uniform positive correlation, revealing more complex dynamics. Diesel and petrol prices positively impact the Ghanaian cedi's exchange rate, which implies a depreciation of the Ghanaian cedi currency. In contrast, cocoa and crude oil prices demonstrate a predominantly negative influence, indicating an appreciation of the Cedi currency. Furthermore, the study uncovers feedback effects and bidirectional relationships between specific commodity prices and exchange rates, highlighting potential self-reinforcing cycles. Outstandingly, incorporating inflation as a factor reveals a positive link between inflation and the exchange rate and a feedback effect, signifying a depreciation of the Cedi currency. These conclusions have policy implications for Ghana's policymakers, financiers, and stakeholders, offering valuable insights to inform policy decisions, risk mitigation strategies, and investment decisions.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"28 ","pages":"Article e02739"},"PeriodicalIF":2.7,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143929585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Socio-ecological factors contributing to the use of slash-and-burn as cropland preparation practice in Burkina Faso","authors":"Pawend-taoré Christian Bougma,&nbsp;Loyapin Bondé,&nbsp;Valaire Séraphin Ouehoudja Yaro,&nbsp;Bruno Nikiéma,&nbsp;Oumarou Ouédraogo","doi":"10.1016/j.sciaf.2025.e02736","DOIUrl":"10.1016/j.sciaf.2025.e02736","url":null,"abstract":"<div><div>Biomass burning (BB) is a widely practiced agricultural method for clearing cropland and a major source of carbon dioxide (CO₂) emissions, contributing to climate change (CC). Understanding the key socio-ecological factors influencing BB use and farmers' knowledge of CC is crucial for decision-making on sustainable land management. This study aimed to: (i) assess the socio-ecological factors influencing the use of biomass burning, (ii) examine farmers' knowledge of the effects of biomass burning on CC, and (iii) identify local alternative practices to reduce BB. A total of 204 smallholder farmers were interviewed across two contrasting climatic zones, Sudanian and Sudano-Sahelian, in Burkina Faso using a semi-structured technique. Our findings revealed that 47.55 % of farmers use fire for land preparation, with cropland age (β = -0.955, <em>p</em> &lt; 0.05), and gender (β = -0.733, <em>p</em> &lt; 0.01), being the primary socio-ecological factors influencing the use of this practice. Smallholders reported that faster field clearance (41 %) and improved soil fertility (23 %) were the main reasons for adopting biomass burning. Results also highlighted that education level (β = -0.569, <em>p</em> &lt; 0.05) and access to extension services (β = -1.711, <em>p</em> &lt; 0.05) were the most significant factors influencing farmers' awareness of climate change and greenhouse gas emissions, respectively. Local alternative practices, such as biomass mulching and composting, have been identified as replacements for BB. Raising awareness among farmers about the environmental impact of BB presents a viable mitigation strategy.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"28 ","pages":"Article e02736"},"PeriodicalIF":2.7,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-efficiency MPPT Using ZVS quasi-resonant converter and PSO algorithm: Simulation and PIL validation","authors":"Souhail Barakat ,&nbsp;Abdelouahed Mesbahi ,&nbsp;Badr N’hili ,&nbsp;Ayoub Nouaiti ,&nbsp;Mohcine Abouyaakoub","doi":"10.1016/j.sciaf.2025.e02704","DOIUrl":"10.1016/j.sciaf.2025.e02704","url":null,"abstract":"<div><div>This paper presents the use of quasi-resonant converters for maximizing power extraction in residential photovoltaic (PV) applications, ensuring high efficiency and optimal energy quality. Quasi-resonant boost converters are implemented to optimize the power transfer process while minimizing switching losses and improving the overall performance of the system. The Particle Swarm Optimization (PSO) technique, which offers a reliable and flexible control mechanism for changing environmental conditions, is used to achieve Maximum Power Point Tracking (MPPT). The proposed system is modeled and simulated in MATLAB Simulink to validate its performance under different operating scenarios. Furthermore, real-time validation is conducted using the Processor-in-the-Loop (PIL) approach, implemented via the LAUNCHXL-F28379D microcontroller. The simulation and PIL results demonstrate the system’s capability to efficiently extract maximum power with high accuracy and energy quality, making it suitable for residential PV installations.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"28 ","pages":"Article e02704"},"PeriodicalIF":2.7,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143929586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A preliminary assessment of the spatial and temporal patterns of sand and dust storms over the Sahara","authors":"Sahar A. Saleh ,&nbsp;Saleh A․ S․ ,&nbsp;Hesham Badawy","doi":"10.1016/j.sciaf.2025.e02729","DOIUrl":"10.1016/j.sciaf.2025.e02729","url":null,"abstract":"<div><div>The Sahara Desert, the preeminent global producer of airborne dust, is crucial for comprehending the geographical and temporal dynamics of sand and dust storms (SDSs), especially as climate change and anthropogenic activities exacerbate desertification. This study offers a spatiotemporal analysis of SDSs in the Sahara from 2000 to 2020, incorporating 2196 daily satellite observations from NASA’s Giovanni and POWER platforms alongside GIS-based regional clustering. We evaluated changes in SDS frequency, intensity, duration, and distribution over the past two decades. This study identified primary dust source locations, such as the Bodélé Depression, Western Sahara, and Libyan-Algerian sand seas, where geomorphological and atmospheric circumstances enable continuous dust emissions. A clear latitudinal gradient in dust activity was observed, with maximum aerosol optical thickness (AOT) occurring between 17° and 20°N, mostly corresponding to the yearly movement of the Intertropical Convergence Zone (ITCZ). However, there is a notable migration of dust deposition centers northward during warm seasons (summer and autumn) and shift southward toward the southern Sahara and West Africa during cold seasons (winter and spring). The results also reveal a statistically significant long-term reduction in SDS frequency, intensity, and duration, ascribed to enhanced Sahelian vegetation, diminishing wind patterns, and changing climate oscillations. In contrast, winter exhibited an increase in SDS activity, perhaps influenced by synoptic-scale meteorological phenomena such as high-pressure anomalies. Overall, the study's methodological framework, which integrates remote sensing and spatial analytics, improves the identification and monitoring of dust sources, thereby can contribute to improving models about radiative forcing, air quality, and transboundary dust movement. Policy implications necessitate the implementation of land management methods to mitigate dust emissions, in conjunction with early warning systems for health and climate adaptation.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"28 ","pages":"Article e02729"},"PeriodicalIF":2.7,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143923606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance enhancement of a single slope solar still using wick materials: A comparative experimental investigation with energy, exergy, and economic analysis","authors":"Saif Ali Kadhim ,&nbsp;Farhan Lafta Rashid ,&nbsp;Karrar A. Hammoodi ,&nbsp;Hussein Togun ,&nbsp;Abdallah Bouabidi ,&nbsp;Ali Habeeb Askar ,&nbsp;Ahmed Kadhim Hussein","doi":"10.1016/j.sciaf.2025.e02733","DOIUrl":"10.1016/j.sciaf.2025.e02733","url":null,"abstract":"<div><div>Despite the many advantages of solar stills, the limited productivity poses a serious challenge. This motivates scholars to find solutions to reduce this obstacle using different enhancement techniques. From this standpoint, this study aims to enhance the productivity of a single slope solar still (4S) using three different wick materials, tested for the first time together under the same conditions: sponge, jute cloth and luffa fiber. To achieve this aim, two identical 4Ss were manufactured from locally available materials, one conventional (without wick) and the other modified (with wick). All tests were conducted in outdoor conditions of Baghdad city and on sunny days, mostly in April. According to the analysis of productivity, energy, exergy, and economic, it was found that the best performance of 4S was with the use of jute cloth wick. Compared to conventional 4S, productivity was enhanced by 5.07 %, 21.08 % and 17.09 %, energy efficiency was enhanced by 4.77 %, 22.06 % and 20.53 %, exergy efficiency was enhanced by 17.30 %, 25.00 % and 22.54 %, and overall gain of the 4S was enhanced by 6.00, 23.49 and 15.54 % with sponge, jute cloth and luffa fiber respectively.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"28 ","pages":"Article e02733"},"PeriodicalIF":2.7,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143923605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of technoeconomic optimization for sizing renewable energy systems using metaheuristic and hybrid algorithms","authors":"Bouafia Mohammed ,&nbsp;El Fathi Amine ,&nbsp;El Akchioui Nabil","doi":"10.1016/j.sciaf.2025.e02712","DOIUrl":"10.1016/j.sciaf.2025.e02712","url":null,"abstract":"<div><div>The escalating global adoption of Renewable Energy (RE) comes from declining costs and expanding electricity demand, driven by environmental imperatives to mitigate carbon emissions and reduce reliance on fossil fuels. Morocco, leveraging its abundant solar and wind resources, represents this transition, with a significant portion of its electricity demand met by RE sources. This study focuses on optimizing grid-connected Hybrid Renewable Energy Systems (HRES) in Morocco using technoeconomic approaches, including metaheuristic algorithms such as Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Grey Wolf Optimization (GWO) and Artificial Bee Colony (ABC) and hybrid methods combining these latter with Modified Marquardt Gradient Descent (MGD). The primary objective is to optimize the Levelized Cost of Electricity (LCOE) for a HRES. The proposed system achieves an annual energy production exceeding 5000 kWh for capacities up to 20 kWp, which is sufficient to meet a daily load demand of 17.12 kWh (equivalent to 6248.8 kWh per year) while ensuring a Renewable Energy Fraction (REF) of at least 80%. According to evaluations conducted in eleven Moroccan cities, hybrid approaches notably, MGD-GWO emerges as a consistently effective solution, demonstrating superior performance in all cities. The lowest overall average LCOE for all cities is 0.114464 $/kW. Among them, the lowest value was recorded in Dakhla at 0.0662 $/kW using a wind capacity of 4781.892 kWp with an initial cost of 5308$. The study's findings offer valuable insights for researchers, policymakers, and investors seeking optimal strategies for sizing RE systems and integrating renewables into the energy landscape.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"28 ","pages":"Article e02712"},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Progress in the application of remote sensing for water quality and human health mapping in informal settlements of South Africa: A review","authors":"Oupa E. Malahlela ,&nbsp;Mologadi C. Mothapo ,&nbsp;Fhumulani I. Mathivha ,&nbsp;Nokulunga Hlengwa","doi":"10.1016/j.sciaf.2025.e02718","DOIUrl":"10.1016/j.sciaf.2025.e02718","url":null,"abstract":"<div><div>Informal settlements in South Africa are a part of the urban landscape which is impossible to ignore due to their socio-economic contribution to the urban economies. However, the rapid expansion of these settlements exposes the population to various environmental hazards such as floods, pollution, and waterborne diseases and thus requires continuous monitoring. The use of remote sensing data has proved very effective for mapping water bodies, water quality, flood risk and water-borne diseases in parts of the world and in South Africa. This review highlights the extent to which remote sensing technology was used for mapping water quality in informal settlements, water-borne diseases, challenges and opportunities that the technology presents for future research. The results from this review revealed that there was a gradual increase in the number of studies conducted for mapping of water quality in South Africa since 1982, with a peak publication of 15 articles in 2020. We found no literature on the application of remote sensing in South African informal settlements in areas of water-borne and water-related disease mapping, such as schistosomiasis, yellow fever, typhoid fever, dysentery, and cholera, among other common water-borne and water-related diseases. Malaria was found to be the most common water related disease that has been studied through remote sensing in South Africa due to the disease burden that exists, and the efforts made towards disease eradication. In this review, the use of unmanned aerial vehicles (UAVs) and high-resolution remote sensing is recommended as an alternative to traditional water-borne and water-related diseases surveillance especially in developing countries.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"28 ","pages":"Article e02718"},"PeriodicalIF":2.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Socio-economic factors influencing the adoption of solar home systems: the case study of Ghana","authors":"Emmanuel Effah ,&nbsp;Samuel Gyamfi ,&nbsp;Felix Amankwah Diawuo ,&nbsp;Emmanuel Yeboah Asuamah","doi":"10.1016/j.sciaf.2025.e02727","DOIUrl":"10.1016/j.sciaf.2025.e02727","url":null,"abstract":"<div><div>This study examines the socio-economic factors influencing the adoption and utilisation of Solar Home Systems (SHSs) in remote communities of Ghana. Using a mixed-methods approach, the research incorporates household surveys of SHS users and non-users, along with in-depth interviews with key stakeholders in the SHS industry. The findings reveal that access to finance, education level, and awareness of SHS benefits are key determinants of adoption. Additionally, the availability of government subsidies and microfinance institutions significantly enhances SHS uptake.</div><div>Despite the advantages of SHSs, the study finds that they are not a primary driver for establishing Home-Based Businesses in rural communities. However, they have contributed to a 3.81 % increase in household savings and improved the operational conditions of existing businesses. Moreover, 41.59 % of respondents reported enhanced nighttime security, while 28 % noted an extension in study hours for children due to improved lighting.</div><div>The study concludes that targeted policy interventions addressing financial accessibility, community engagement, and infrastructure support are essential for maximising the socio-economic benefits of SHSs. Expanding SHS adoption in developing countries can significantly improve energy access, quality of life, and rural economic resilience.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"28 ","pages":"Article e02727"},"PeriodicalIF":2.7,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}