Pub Date : 2024-10-11DOI: 10.1016/j.sciaf.2024.e02423
Amos Kipkorir Langat , Samuel Musili Mwalili , Lawrence Ndekeleni Kazembe
Measurement errors present a substantial challenge in accurately determining optimal fertilizer application levels, directly impacting agricultural efficiency and cost-effectiveness. This study examines the use of Hierarchical Bayesian Semi-Parametric (HBS) models to correct these errors, thereby improving precision in agricultural decision-making. By applying these models to a decade of data from Uasin Gishu County, Kenya, we evaluated key variables including maize yield, land size, and fertilizer levels. The results indicate that the HBS models effectively mitigate both systematic and random errors, leading to more accurate fertilizer recommendations. This advancement supports better resource management and higher crop yields. Our findings underscore the value of Bayesian methods in agricultural data analysis and highlight the critical role of accurate measurement and correction in achieving optimal outcomes. The implications of this research extend to improved decision-making processes and more sustainable agricultural practices.
{"title":"Hierarchical Bayesian semi-parametric models for measurement error correction in determining optimal fertilizer application levels","authors":"Amos Kipkorir Langat , Samuel Musili Mwalili , Lawrence Ndekeleni Kazembe","doi":"10.1016/j.sciaf.2024.e02423","DOIUrl":"10.1016/j.sciaf.2024.e02423","url":null,"abstract":"<div><div>Measurement errors present a substantial challenge in accurately determining optimal fertilizer application levels, directly impacting agricultural efficiency and cost-effectiveness. This study examines the use of Hierarchical Bayesian Semi-Parametric (HBS) models to correct these errors, thereby improving precision in agricultural decision-making. By applying these models to a decade of data from Uasin Gishu County, Kenya, we evaluated key variables including maize yield, land size, and fertilizer levels. The results indicate that the HBS models effectively mitigate both systematic and random errors, leading to more accurate fertilizer recommendations. This advancement supports better resource management and higher crop yields. Our findings underscore the value of Bayesian methods in agricultural data analysis and highlight the critical role of accurate measurement and correction in achieving optimal outcomes. The implications of this research extend to improved decision-making processes and more sustainable agricultural practices.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"26 ","pages":"Article e02423"},"PeriodicalIF":2.7,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents the performance analysis of a mono-stage three-phase DC-AC converter with reduced logic power supply circuits. The power DC-AC power converter of the proposed system is formed by arrangement of one inductor, two power switches, and one capacitor in an opener-like configuration to yield each leg of the inverter. During the inversion process, the number of capacitor elements that charges up (builds electrical energy) or discharges across the power switches will be equal to the number of inductors that discharges or builds up magnetic energy that terminates in between the power switches and vice versa. Under this condition, the proposed system, boosts and converts DC power to AC power and at the same time maintains energy balance in the system in one stage power conversion phenomenon unlike conventional power inverters. The logic power supply circuit used in the proposed system has fewer component counts and performs optical isolation unlike its conventional counterparts which have larger component counts and isolate by electromagnetic induction. The proposed system achieved the following results: lower and cheaper logic power supply circuits, simulated phase voltages of 327.8 V and 326.6 V and 329.8 V at THDs of 0.09879 %, 0.2569 % and 0.2905 % and average phase currents of 6.30A, 6.32A and 6.26A, respectively, and experimented: scaled down phase-A, B, and C average voltages of 66.95 V, 65.6 V and 68.93 V at phase angles of 0°, 120°, and -120° respectively. The performance analysis of the mono-stage three-phase DC-AC converter with reduced logic power supply circuits can be used in home appliances, hospital equipment, communication-based power stations, and drive systems such as electric vehicles.
本文介绍了一种单级三相直流-交流转换器的性能分析，该转换器具有简化的逻辑电源电路。拟议系统的功率直流-交流电源转换器由一个电感器、两个功率开关和一个电容器组成，以类似开路器的配置产生逆变器的每一脚。在反相过程中，在功率开关两端充电（积累电能）或放电的电容器元件数量与在功率开关两端放电或积累磁能的电感器数量相等，反之亦然。在此条件下，与传统的电源逆变器不同，拟议的系统可将直流电升压并转换为交流电，同时在单级电源转换现象中保持系统的能量平衡。与元件数量较多且通过电磁感应进行隔离的传统同类产品不同，拟议系统中使用的逻辑电源电路元件数量较少，并能进行光学隔离。拟议系统取得了以下成果：逻辑电源电路更低廉，模拟相电压分别为 327.8 V、326.6 V 和 329.8 V，总谐波失真分别为 0.09879 %、0.2569 % 和 0.2905 %，平均相电流分别为 6.30A、6.32A 和 6.26A，并进行了实验：在相位角为 0°、120° 和 -120° 时，按比例缩小的 A、B 和 C 相平均电压分别为 66.95 V、65.6 V 和 68.93 V。单级三相直流-交流转换器的性能分析与简化逻辑电源电路可用于家用电器、医院设备、基于通信的发电站以及电动汽车等驱动系统。
{"title":"Performance analysis of mono-stage three-phase DC-AC converter with reduced logic power supply circuits","authors":"Candidus U. Eya , Ayodeji Olalekan Salau , Crescent Onyebuchi Omeje","doi":"10.1016/j.sciaf.2024.e02421","DOIUrl":"10.1016/j.sciaf.2024.e02421","url":null,"abstract":"<div><div>This paper presents the performance analysis of a mono-stage three-phase DC-AC converter with reduced logic power supply circuits. The power DC-AC power converter of the proposed system is formed by arrangement of one inductor, two power switches, and one capacitor in an opener-like configuration to yield each leg of the inverter. During the inversion process, the number of capacitor elements that charges up (builds electrical energy) or discharges across the power switches will be equal to the number of inductors that discharges or builds up magnetic energy that terminates in between the power switches and vice versa. Under this condition, the proposed system, boosts and converts DC power to AC power and at the same time maintains energy balance in the system in one stage power conversion phenomenon unlike conventional power inverters. The logic power supply circuit used in the proposed system has fewer component counts and performs optical isolation unlike its conventional counterparts which have larger component counts and isolate by electromagnetic induction. The proposed system achieved the following results: lower and cheaper logic power supply circuits, simulated phase voltages of 327.8 V and 326.6 V and 329.8 V at THDs of 0.09879 %, 0.2569 % and 0.2905 % and average phase currents of 6.30A, 6.32A and 6.26A, respectively, and experimented: scaled down phase-A, B, and C average voltages of 66.95 V, 65.6 V and 68.93 V at phase angles of 0°, 120°, and -120° respectively<em>.</em> The performance analysis of the mono-stage three-phase DC-AC converter with reduced logic power supply circuits can be used in home appliances, hospital equipment, communication-based power stations, and drive systems such as electric vehicles.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"26 ","pages":"Article e02421"},"PeriodicalIF":2.7,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-10DOI: 10.1016/j.sciaf.2024.e02348
Lunga Matsebula , Farai Nyabadza
Waterborne infections such as Cholera and Typhoid remain a huge burden on the public health systems of poor countries in Africa and Asia. The highest disease burden is concentrated in sub-Saharan Africa. In most regions, the recent spike in cases of both infections is attributed to dilapidated infrastructure and poor hygiene. This paper examines the role of poor hygiene in the surge of both infections. We use a system of non-linear ordinary differential equations to model the movement of people between the different classes of infections, and we use a sigmoidal function to model the different levels of hygiene in a community. The findings demonstrate that managing hygiene, even if limited to the direct transmission route, can significantly reduce the prevalence of both infections. This paper presents some of the public health implications of these findings.
{"title":"A mathematical model of Cholera–Typhoid coinfection dynamics with a hygiene-driven contact rate","authors":"Lunga Matsebula , Farai Nyabadza","doi":"10.1016/j.sciaf.2024.e02348","DOIUrl":"10.1016/j.sciaf.2024.e02348","url":null,"abstract":"<div><div>Waterborne infections such as Cholera and Typhoid remain a huge burden on the public health systems of poor countries in Africa and Asia. The highest disease burden is concentrated in sub-Saharan Africa. In most regions, the recent spike in cases of both infections is attributed to dilapidated infrastructure and poor hygiene. This paper examines the role of poor hygiene in the surge of both infections. We use a system of non-linear ordinary differential equations to model the movement of people between the different classes of infections, and we use a sigmoidal function to model the different levels of hygiene in a community. The findings demonstrate that managing hygiene, even if limited to the direct transmission route, can significantly reduce the prevalence of both infections. This paper presents some of the public health implications of these findings.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"26 ","pages":"Article e02348"},"PeriodicalIF":2.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142438248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1016/j.sciaf.2024.e02420
Nat Owusu-Prempeh , Leonard K. Amekudzi , Boateng Kyereh
Soil respiration (SR) emits a vast amount of atmospheric carbon dioxide (CO2) and contributes largely to the global greenhouse gas budget. The study assessed the dynamics of SR rates in the Vea catchment in northeastern Ghana, a sparsely gauged semi-arid savannah ecosystem characterized by distinct patterns of soil CO2 efflux. Through field measurements using soil chambers, the study quantified soil CO2 efflux rates in different land use types (woodland, cropland and grazeland), and assessed the influence of soil moisture, temperature, and soil organic carbon stocks on SR variability. The highest soil CO2 fluxes (12.97 ± 0.89 Mg CO2C ha−1 yr−1) were recorded in woodland, followed by grazeland (9.10 ± 0.42 Mg CO2C ha−1 yr−1) with cropland having the lowest rate (5.61 ± 0.29 Mg CO2C ha−1 yr−1). We recorded mean annual soil CO2 flux of 9.23 ± 0.53 Mg CO2C ha−1 yr−1 across the land use types and also observed significant seasonal and spatial variations in SR rates. The highest SR rate (220 mg CO2C m−2h−1) was recorded in the wet months (Jul-Sept and Mar-May) and the lowest rate (30 mg CO2C m−2h−1) in the dry months (Nov-Jan). For the wet season, the mean weekly soil CO2 fluxes ranged between 140 and 160 mg CO2C m−2 hr−1 as opposed to 60–75 mg CO2C m−2 hr−1 for the dry season. Seasonal and spatial variations in SR rates were largely driven by land use type, soil moisture and the interaction of soil temperature and moisture. The results underscore the importance of understanding the emission patterns from various land uses in West African savanna ecosystems to harnessing their potential for climate change mitigation.
{"title":"Assessment of soil carbon dioxide efflux from contrasting land uses in a semi-arid savannah ecosystem, northeastern Ghana (West Africa)","authors":"Nat Owusu-Prempeh , Leonard K. Amekudzi , Boateng Kyereh","doi":"10.1016/j.sciaf.2024.e02420","DOIUrl":"10.1016/j.sciaf.2024.e02420","url":null,"abstract":"<div><div>Soil respiration (SR) emits a vast amount of atmospheric carbon dioxide (CO<sub>2</sub>) and contributes largely to the global greenhouse gas budget. The study assessed the dynamics of SR rates in the Vea catchment in northeastern Ghana, a sparsely gauged semi-arid savannah ecosystem characterized by distinct patterns of soil CO<sub>2</sub> efflux. Through field measurements using soil chambers, the study quantified soil CO<sub>2</sub> efflux rates in different land use types (woodland, cropland and grazeland), and assessed the influence of soil moisture, temperature, and soil organic carbon stocks on SR variability. The highest soil CO<sub>2</sub> fluxes (12.97 ± 0.89 Mg CO<sub>2</sub><sub><img></sub>C ha<sup>−1</sup> yr<sup>−1</sup>) were recorded in woodland, followed by grazeland (9.10 ± 0.42 Mg CO<sub>2</sub><sub><img></sub>C ha<sup>−1</sup> yr<sup>−1</sup>) with cropland having the lowest rate (5.61 ± 0.29 Mg CO<sub>2</sub><sub><img></sub>C ha<sup>−1</sup> yr<sup>−1</sup>). We recorded mean annual soil CO<sub>2</sub> flux of 9.23 ± 0.53 Mg CO<sub>2</sub><sub><img></sub>C ha<sup>−1</sup> yr<sup>−1</sup> across the land use types and also observed significant seasonal and spatial variations in SR rates. The highest SR rate (220 mg CO<sub>2</sub><sub><img></sub>C <em>m</em><sup>−2</sup> <em>h</em><sup>−1</sup>) was recorded in the wet months (Jul-Sept and Mar-May) and the lowest rate (30 mg CO<sub>2</sub><sub><img></sub>C <em>m</em><sup>−2</sup> <em>h</em><sup>−1</sup>) in the dry months (Nov-Jan). For the wet season, the mean weekly soil CO<sub>2</sub> fluxes ranged between 140 and 160 mg CO<sub>2</sub><sub><img></sub>C <em>m</em><sup>−2</sup> hr<sup>−1</sup> as opposed to 60–75 mg CO<sub>2</sub><sub><img></sub>C <em>m</em><sup>−2</sup> hr<sup>−1</sup> for the dry season. Seasonal and spatial variations in SR rates were largely driven by land use type, soil moisture and the interaction of soil temperature and moisture. The results underscore the importance of understanding the emission patterns from various land uses in West African savanna ecosystems to harnessing their potential for climate change mitigation.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"26 ","pages":"Article e02420"},"PeriodicalIF":2.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-08DOI: 10.1016/j.sciaf.2024.e02422
Anteneh Mulugeta Eyasu , Temesgen Zewotir , Zelalem G. Dessie
Recent evidence shows the highest prevalence of multidimensional poverty in the world. To alleviate poverty, Ethiopia is investing in stimulating agricultural commercialization for poverty reduction, driving sustainable economic growth, and creating jobs. Therefore, this study investigated the causal relationship between crop commercialization and multidimensional poverty across Ethiopian rural households using the Ethiopia Socioeconomic Survey 2018/19 data, which included 1129 crop commercialized and 1585 completely subsistence rural households. Moreover, this study also examined the causal effect of crop commercialization on the multidimensional poverty mediated by mobile phone ownership status. The study used the double robust method of the augmented inverse probability of treatment weighted (AIPTW) and targeted maximum likelihood estimation (TMLE) methods. The result showed that crop commercialization has an association with multidimensional poverty. Specifically, the TMLE with a default super learner model estimates were the most precise and suggest that the prevalence of risk of being multidimensionally poor among rural households who were crop commercialized is 12.2 % lower than for those who were completely subsistence households. Thus, it is important to have more robust policies like crop commercialization to target rural multidimensional poverty reduction. Moreover, the controlled direct effect estimation analyses showed that crop-commercialized rural households reduced the adjusted risk of multidimensional poverty by; 12 % for those who owned mobile phones and 7.8 % for those who did not. To ensure sustainable livelihoods for rural multidimensional poor households, it is necessary to have a multidisciplinary policy intervention to promote crop commercialization through the spread of mobile phones in rural areas.
{"title":"Association of crop commercialization and rural households' multidimensional poverty using targeted maximum likelihood estimation","authors":"Anteneh Mulugeta Eyasu , Temesgen Zewotir , Zelalem G. Dessie","doi":"10.1016/j.sciaf.2024.e02422","DOIUrl":"10.1016/j.sciaf.2024.e02422","url":null,"abstract":"<div><div>Recent evidence shows the highest prevalence of multidimensional poverty in the world. To alleviate poverty, Ethiopia is investing in stimulating agricultural commercialization for poverty reduction, driving sustainable economic growth, and creating jobs. Therefore, this study investigated the causal relationship between crop commercialization and multidimensional poverty across Ethiopian rural households using the Ethiopia Socioeconomic Survey 2018/19 data, which included 1129 crop commercialized and 1585 completely subsistence rural households. Moreover, this study also examined the causal effect of crop commercialization on the multidimensional poverty mediated by mobile phone ownership status. The study used the double robust method of the augmented inverse probability of treatment weighted (AIPTW) and targeted maximum likelihood estimation (TMLE) methods. The result showed that crop commercialization has an association with multidimensional poverty. Specifically, the TMLE with a default super learner model estimates were the most precise and suggest that the prevalence of risk of being multidimensionally poor among rural households who were crop commercialized is 12.2 % lower than for those who were completely subsistence households. Thus, it is important to have more robust policies like crop commercialization to target rural multidimensional poverty reduction. Moreover, the controlled direct effect estimation analyses showed that crop-commercialized rural households reduced the adjusted risk of multidimensional poverty by; 12 % for those who owned mobile phones and 7.8 % for those who did not. To ensure sustainable livelihoods for rural multidimensional poor households, it is necessary to have a multidisciplinary policy intervention to promote crop commercialization through the spread of mobile phones in rural areas.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"26 ","pages":"Article e02422"},"PeriodicalIF":2.7,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-08DOI: 10.1016/j.sciaf.2024.e02417
Soukaina Nady, Hassan El Fadil, Zakaria El Idrissi, Abdellah Lassioui, Abdessamad Intidam, Hasni Anwar
The global energy evolution is at a critical juncture, necessitating an urgent transition towards clean and sustainable energy sources, notably green hydrogen, to combat climate change and the inevi-table depletion of fossil fuels. This transition is underscored by the emergence of fuel cell electric vehicles (FCEVs) as a promising solution for clean transportation, demanding advanced DC-DC power converter technologies to ensure their efficiency and reliability. This paper addresses the topic of control for the Quadratic Boost Converter, which presents a challenge due to its non-minimum phase characteristic and nonlinear nature. To tackle this, a nonlinear controller is developed using dual-loop control employing STA-SMC and Lyapunov theory as the control ap-proach. Simulation and experimental validation evaluate the controller's performance, testing ro-bustness against varying load currents and under time-varying reference voltages to assess its ef-fectiveness.
{"title":"Development and experimental validation of high-order sliding mode control for quadratic boost converters in fuel cell electric vehicles","authors":"Soukaina Nady, Hassan El Fadil, Zakaria El Idrissi, Abdellah Lassioui, Abdessamad Intidam, Hasni Anwar","doi":"10.1016/j.sciaf.2024.e02417","DOIUrl":"10.1016/j.sciaf.2024.e02417","url":null,"abstract":"<div><div>The global energy evolution is at a critical juncture, necessitating an urgent transition towards clean and sustainable energy sources, notably green hydrogen, to combat climate change and the inevi-table depletion of fossil fuels. This transition is underscored by the emergence of fuel cell electric vehicles (FCEVs) as a promising solution for clean transportation, demanding advanced DC-DC power converter technologies to ensure their efficiency and reliability. This paper addresses the topic of control for the Quadratic Boost Converter, which presents a challenge due to its non-minimum phase characteristic and nonlinear nature. To tackle this, a nonlinear controller is developed using dual-loop control employing STA-SMC and Lyapunov theory as the control ap-proach. Simulation and experimental validation evaluate the controller's performance, testing ro-bustness against varying load currents and under time-varying reference voltages to assess its ef-fectiveness.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"26 ","pages":"Article e02417"},"PeriodicalIF":2.7,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The diversification of livelihoods by households has been widely acknowledged as a way to overcome food insecurity and poverty challenges in developing countries. Diversification of livelihoods helps spread the risk among multiple livelihood earning activities to provide households with a range of their food needs all year round. By examining the integrated livelihood systems of 405 rural farm households in the Upper East Region of Ghana, empirical evidence is provided in this study using the Sustainable Livelihoods Framework to advance arguments in the literature for the creation of sustainable strategies that improve diversified livelihood systems. The mean diversification indices estimated were 0.45 for agricultural diversification systems, 0.32 for non-agricultural diversification systems and 0.59 for integrated agricultural and non-agricultural diversification systems. With the use of the Cragg two-step regression model, we demonstrate that the decision to diversify and the extent of diversification of rural livelihoods are distinct decisions and are influenced by distinct sets of factors. Similarly, for the three categories of livelihood diversification studied, the effect of these factors also differed. The results emphasize the significance of access to good road network, credit and market information in encouraging rural farm households to diversify their livelihoods. In the short term, improving access to credit and market information through community-based initiatives can provide immediate support to rural households. Communities should also organize local markets and cooperatives to strengthen their economic resilience. While government and stakeholders should focus on long-term infrastructure projects, these community actions can complement such efforts and contribute to achieving global and regional goals targeting food insecurity and poverty eradication.
{"title":"Determinants of livelihood diversification in an integrated agricultural and non-agricultural livelihood system in Ghana","authors":"Jude Dokbila Kolog , Freda Elikplim Asem , Akwasi Mensah-Bonsu , Roger Ayimbillah Atinga","doi":"10.1016/j.sciaf.2024.e02413","DOIUrl":"10.1016/j.sciaf.2024.e02413","url":null,"abstract":"<div><div>The diversification of livelihoods by households has been widely acknowledged as a way to overcome food insecurity and poverty challenges in developing countries. Diversification of livelihoods helps spread the risk among multiple livelihood earning activities to provide households with a range of their food needs all year round. By examining the integrated livelihood systems of 405 rural farm households in the Upper East Region of Ghana, empirical evidence is provided in this study using the Sustainable Livelihoods Framework to advance arguments in the literature for the creation of sustainable strategies that improve diversified livelihood systems. The mean diversification indices estimated were 0.45 for agricultural diversification systems, 0.32 for non-agricultural diversification systems and 0.59 for integrated agricultural and non-agricultural diversification systems. With the use of the Cragg two-step regression model, we demonstrate that the decision to diversify and the extent of diversification of rural livelihoods are distinct decisions and are influenced by distinct sets of factors. Similarly, for the three categories of livelihood diversification studied, the effect of these factors also differed. The results emphasize the significance of access to good road network, credit and market information in encouraging rural farm households to diversify their livelihoods. In the short term, improving access to credit and market information through community-based initiatives can provide immediate support to rural households. Communities should also organize local markets and cooperatives to strengthen their economic resilience. While government and stakeholders should focus on long-term infrastructure projects, these community actions can complement such efforts and contribute to achieving global and regional goals targeting food insecurity and poverty eradication.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"26 ","pages":"Article e02413"},"PeriodicalIF":2.7,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Marginal Folds, in the north-western axis of Moroccan eastern High Atlas, are mainly composed of the Infra-Cenomanian terrains. These latter contain continental detrital deposits (red beds) and are characterized by a network of fractures. These marginal folds host significant concentrations of metallic minerals, such as Cu, Pb, Ag, and Zn, particularly at the Merija (Cu) and Bou Sellam (Pb-Zn) sites.
Several techniques were applied to the Landsat-8 Oli images to improve the clarity and visibility of the linear features. Radiometric and atmospheric corrections, color compositions, directional filters, and principal component analysis were adopted. The lineaments resulting from automatic extraction, as well as their statistical analysis were validated by visual interpretation and field investigations. Statistical analysis revealed three dominants fracture systems: N-S, NE-SW, and E-W; the first two systems show a high density in the study area.
The mineral alteration of the outcropping rocks is well described by ASTER multispectral imaging techniques. In this work, the effectiveness of this techniques for mineral alteration mapping was demonstrated on the Merija area. Several occurrences of mineral alteration were highlighted, using a combination of false color and band ratios, the principal component analysis (PCA), and the band ratios. This research was completed by reflectance spectrometry, covering the visible, near-infrared (VNIR), and short-wave infrared (SWIR) domains, to identify mineral alteration.
Hydrothermal alteration in the Merija region includes clay, phyllite, carbonate, and phyllosilicate alteration, such as kaolinite, illite, montmorillonite, palygorskite, and vermiculite. Regarding to oxidation, as evidenced by the presence of goethite, jarosite, and hematite, it is widespread in most of the analyzed samples, resulting from the alteration of pyrite, followed by jarosite and goethite.
边缘褶皱位于摩洛哥东部高阿特拉斯的西北轴线上，主要由下元古代地形组成。后者含有大陆碎屑沉积物（红床），并以断裂网络为特征。这些边缘褶皱蕴藏着大量金属矿物，如铜、铅、银和锌，尤其是在 Merija（铜）和 Bou Sellam（铅锌）地点。对 Landsat-8 Oli 图像采用了多种技术，以提高线性特征的清晰度和可视性。采用了辐射和大气校正、色彩合成、定向滤光片和主成分分析等技术。通过目视判读和实地调查，对自动提取的线状特征及其统计分析进行了验证。统计分析揭示了三种主要的断裂系统：ASTER 多光谱成像技术很好地描述了露头岩石的矿物蚀变。在这项工作中，Merija 地区展示了该技术在绘制矿物蚀变图方面的有效性。利用假色和波段比、主成分分析（PCA）和波段比的组合，突出显示了几处矿物蚀变。这项研究是通过反射光谱法完成的，涵盖了可见光、近红外（VNIR）和短波红外（SWIR）领域，以确定矿物蚀变。Merija 地区的热液蚀变包括粘土、辉绿岩、碳酸盐和植硅酸盐蚀变，如高岭石、伊利石、蒙脱石、辉绿岩和蛭石。在氧化方面，大多数分析样本中都普遍存在氧化现象，这体现在黄铁矿、绿泥石和赤铁矿的存在上，其原因是黄铁矿的蚀变，其次是绿泥石和黄铁矿的蚀变。
{"title":"Reflectance spectrometry and multispectral data for mapping fractures and hydrothermal alterations in the northern edge of the eastern High Atlas, Morocco","authors":"Asma Zouggarh , Mourad Essalhi , Adnane Tobi , Omar Saidi , Daoud El Azmi , Mohammed Boumehdi , Saloua Mnissar Himyari","doi":"10.1016/j.sciaf.2024.e02416","DOIUrl":"10.1016/j.sciaf.2024.e02416","url":null,"abstract":"<div><div>The Marginal Folds, in the north-western axis of Moroccan eastern High Atlas, are mainly composed of the Infra-Cenomanian terrains. These latter contain continental detrital deposits (red beds) and are characterized by a network of fractures. These marginal folds host significant concentrations of metallic minerals, such as Cu, Pb, Ag, and Zn, particularly at the Merija (Cu) and Bou Sellam (Pb-Zn) sites.</div><div>Several techniques were applied to the Landsat-8 Oli images to improve the clarity and visibility of the linear features. Radiometric and atmospheric corrections, color compositions, directional filters, and principal component analysis were adopted. The lineaments resulting from automatic extraction, as well as their statistical analysis were validated by visual interpretation and field investigations. Statistical analysis revealed three dominants fracture systems: N-S, NE-SW, and E-W; the first two systems show a high density in the study area.</div><div>The mineral alteration of the outcropping rocks is well described by ASTER multispectral imaging techniques. In this work, the effectiveness of this techniques for mineral alteration mapping was demonstrated on the Merija area. Several occurrences of mineral alteration were highlighted, using a combination of false color and band ratios, the principal component analysis (PCA), and the band ratios. This research was completed by reflectance spectrometry, covering the visible, near-infrared (VNIR), and short-wave infrared (SWIR) domains, to identify mineral alteration.</div><div>Hydrothermal alteration in the Merija region includes clay, phyllite, carbonate, and phyllosilicate alteration, such as kaolinite, illite, montmorillonite, palygorskite, and vermiculite. Regarding to oxidation, as evidenced by the presence of goethite, jarosite, and hematite, it is widespread in most of the analyzed samples, resulting from the alteration of pyrite, followed by jarosite and goethite.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"26 ","pages":"Article e02416"},"PeriodicalIF":2.7,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-04DOI: 10.1016/j.sciaf.2024.e02419
Ojochenemi Ejeh Yakubu , Chukwuma Stephen Ezeonu , David Ata Agyo , Tsuvini Jonah , Ebenezer Morayo Ale
<div><h3>Background and Aim</h3><div>Diabetes mellitus is associated with haematological abnormalities and oxidative stress, contributing to disease progression and complications. <em>Adansonia digitata</em>, is a traditional medicinal plant well known for its potential therapeutic properties. This study investigates the effects of methanolic stem-bark extracts of <em>Adansonia digitata</em> on haematological and antioxidant status in streptozotocin-induced diabetic rats.</div></div><div><h3>Experimental Procedure</h3><div>Fourty-two wistar rats were distributed into 6 groups of 7 each. Group 1 served as normal control, group 2 to 6 animals were made diabetic by intraperitoneal administration of single dose of 50 mg kg<sup>-1</sup> streptozotocin. Group 2 served as the negative control and did not receive treatment, group 3 served as the positive control and received 150 mg kg<sup>-1</sup> metformin (Glucophage) (standard drug), while group 4, 5 and 6 received oral treatment of 100 mg kg<sup>-1</sup>, 200 mg kg<sup>-1</sup> and 300 mg kg<sup>-1</sup> of <em>Adansonia digitata</em> stem-bark methanolic extract respectively for 21days, after which the animals were sacrificed, and blood and liver were collected for haematological analysis including White Blood cell (WBC), red blood cell (RBC), haemoglobin (HGB), hematocrit (H CT), platelet (PLT), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), total bilirubin (TB), direct bilirubin(DB) and indirect bilirubin (IB) concentration and antioxidant parameters including antioxidant enzymes [catalase (CAT) and superoxide dismutase (SOD) activities] and oxidative stress marker [thiobarbituric acid reactive substance (TBARS)].</div></div><div><h3>Results</h3><div>STZ administration evoked a marked (<em>p</em> < 0.05) decline in the level of WBC, RBC, HGB, PLT, LYM and MCV in the diabetic rats when compared with the normal control. Howbeit, treatment with methanolic extracts of <em>adansonia digitata</em> stem-bark led to a profound (<em>p</em> < 0.05) increase in concentrations of these parameters close to the normal. In addition, STZ caused a non-significant (<em>p</em> > 0.05) decrease in MCH and MCHC. On the contrary, STZ caused an insignificant (<em>p</em> > 0.05) increase in the levels of TB and DB, but a significant (<em>p</em> > 0.05) increase IDB level in the diabetic control group when compared with the normal control group, while treatment with stem-bark extracts resulted in a marked (<em>p</em> > 0.05) fall in IDB level. Furthermore, there was a marked (<em>P</em> < 0.05) reduction in the activity of hepatic CAT and SOD and a considerable (<em>P</em> < 0.05) elevation in Malondialdehyde (MDA) level in the hepatic tissue of the diabetic control. Nonetheless, <em>Adansonia digitata</em> stem-bark extracts profoundly (<em>P</em> < 0.05) raised the activities of the enzymes and concomitantly counteracted MD
{"title":"Methanolic stem-bark extracts of Adansonia digitata modulates haematological and antioxidant parameters in streptozotocin-induced diabetic rats","authors":"Ojochenemi Ejeh Yakubu , Chukwuma Stephen Ezeonu , David Ata Agyo , Tsuvini Jonah , Ebenezer Morayo Ale","doi":"10.1016/j.sciaf.2024.e02419","DOIUrl":"10.1016/j.sciaf.2024.e02419","url":null,"abstract":"<div><h3>Background and Aim</h3><div>Diabetes mellitus is associated with haematological abnormalities and oxidative stress, contributing to disease progression and complications. <em>Adansonia digitata</em>, is a traditional medicinal plant well known for its potential therapeutic properties. This study investigates the effects of methanolic stem-bark extracts of <em>Adansonia digitata</em> on haematological and antioxidant status in streptozotocin-induced diabetic rats.</div></div><div><h3>Experimental Procedure</h3><div>Fourty-two wistar rats were distributed into 6 groups of 7 each. Group 1 served as normal control, group 2 to 6 animals were made diabetic by intraperitoneal administration of single dose of 50 mg kg<sup>-1</sup> streptozotocin. Group 2 served as the negative control and did not receive treatment, group 3 served as the positive control and received 150 mg kg<sup>-1</sup> metformin (Glucophage) (standard drug), while group 4, 5 and 6 received oral treatment of 100 mg kg<sup>-1</sup>, 200 mg kg<sup>-1</sup> and 300 mg kg<sup>-1</sup> of <em>Adansonia digitata</em> stem-bark methanolic extract respectively for 21days, after which the animals were sacrificed, and blood and liver were collected for haematological analysis including White Blood cell (WBC), red blood cell (RBC), haemoglobin (HGB), hematocrit (H CT), platelet (PLT), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), total bilirubin (TB), direct bilirubin(DB) and indirect bilirubin (IB) concentration and antioxidant parameters including antioxidant enzymes [catalase (CAT) and superoxide dismutase (SOD) activities] and oxidative stress marker [thiobarbituric acid reactive substance (TBARS)].</div></div><div><h3>Results</h3><div>STZ administration evoked a marked (<em>p</em> < 0.05) decline in the level of WBC, RBC, HGB, PLT, LYM and MCV in the diabetic rats when compared with the normal control. Howbeit, treatment with methanolic extracts of <em>adansonia digitata</em> stem-bark led to a profound (<em>p</em> < 0.05) increase in concentrations of these parameters close to the normal. In addition, STZ caused a non-significant (<em>p</em> > 0.05) decrease in MCH and MCHC. On the contrary, STZ caused an insignificant (<em>p</em> > 0.05) increase in the levels of TB and DB, but a significant (<em>p</em> > 0.05) increase IDB level in the diabetic control group when compared with the normal control group, while treatment with stem-bark extracts resulted in a marked (<em>p</em> > 0.05) fall in IDB level. Furthermore, there was a marked (<em>P</em> < 0.05) reduction in the activity of hepatic CAT and SOD and a considerable (<em>P</em> < 0.05) elevation in Malondialdehyde (MDA) level in the hepatic tissue of the diabetic control. Nonetheless, <em>Adansonia digitata</em> stem-bark extracts profoundly (<em>P</em> < 0.05) raised the activities of the enzymes and concomitantly counteracted MD","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"26 ","pages":"Article e02419"},"PeriodicalIF":2.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.sciaf.2024.e02414
Francis Wilson Owusu , Mary Mamle Apetorgbor , James Kofi Korang , Courage Alorbu , Emmanuel Appiah-Kubi , Rado Gazo , Francis Asare
This study assessed the possibility and feasibility of using two Eucalyptus species for electricity transmission poles in Ghana as a means of minimizing the import of transmission poles in the country. Eucalyptus species are grown in private and government-owned plantations in Ghana due to its growing demand for use as power line transmission poles. The species are seldom used by the furniture industry. The demand from the pole treatment industry for raw materials exceeds the domestic supply of teak, which is commonly used as transmission poles, resulting in the importation of pine poles to cover the deficit, hence the need for this study. The natural durability of Eucalyptus alba and Eucalyptus robusta in the Coastal Savanna Zone (CSZ) and Moist Semi-Deciduous Forest Zone (MSDFZ) was tested using white rot fungus (Coriolopsis polyzona) under an accelerated laboratory test. The results indicated significant variations in the mass lossess be-tween trees in the two vegetation zones. The sapwood and outer heartwood of the E. alba tree species of CSZ recorded the highest mass losses of 41.21 % and 20.79 %, respectively, compared to the E. robusta trees felled from MSDFZ that recorded mass losses of 32.3 % and 5.42 %, respectively. Also, the outer heart- wood and inner heartwood of the E. robusta MSDFZ felled trees were highly resistant (5.42 % and 6.99 %). CSZ wood species were less naturally resistant to C. polyzona attack than those harvested from MSDFZ, which appeared to be less susceptible and more naturally resistant to decay by C. polyzona. Both species are feasible for use as transmission line poles; however, trees from both ecological zones would need chemical preservatives to improve their service life, especially for outdoor applications.
本研究评估了在加纳使用两种桉树树种作为输电线杆的可能性和可行性，以尽量减少该国输电线杆的进口量。加纳私人和政府所有的种植园都种植桉树，因为用作输电线杆的需求日益增长。家具行业很少使用这些树种。电线杆处理行业对原材料的需求超过了国内常用于输电线杆的柚木的供应量，因此需要进口松木电线杆来弥补缺口，因此需要进行这项研究。在加速实验室测试中，使用白腐真菌（Coriolopsis polyzona）对沿海热带草原区（CSZ）和潮湿半落叶林区（MSDFZ）的白桉和罗布斯塔桉的天然耐久性进行了测试。结果表明，两个植被带树木的质量损失差异很大。CSZ 的 E. alba 树种边材和外心材的质量损失最大，分别为 41.21 % 和 20.79 %，而从 MSDFZ 砍伐的 E. robusta 树种的质量损失分别为 32.3 % 和 5.42 %。此外，被 MSDFZ 砍伐的 E. robusta 树木的外心材和内心材具有很强的抗性（5.42 % 和 6.99 %）。与采自 MSDFZ 的木材相比，采自 CSZ 的木材对多佐纳菌侵袭的天然抵抗力较弱，而采自 MSDFZ 的木材对多佐纳菌腐烂的易感性较低，天然抵抗力较强。这两种树种都可以用作输电线杆；不过，这两个生态区的树木都需要化学防腐剂来提高其使用寿命，尤其是在室外应用时。
{"title":"Natural durability of Eucalyptus species harvested as electricity transmission poles in two different ecological zones of Ghana","authors":"Francis Wilson Owusu , Mary Mamle Apetorgbor , James Kofi Korang , Courage Alorbu , Emmanuel Appiah-Kubi , Rado Gazo , Francis Asare","doi":"10.1016/j.sciaf.2024.e02414","DOIUrl":"10.1016/j.sciaf.2024.e02414","url":null,"abstract":"<div><div>This study assessed the possibility and feasibility of using two <em>Eucalyptus</em> species for electricity transmission poles in Ghana as a means of minimizing the import of transmission poles in the country. <em>Eucalyptus</em> species are grown in private and government-owned plantations in Ghana due to its growing demand for use as power line transmission poles. The species are seldom used by the furniture industry. The demand from the pole treatment industry for raw materials exceeds the domestic supply of teak, which is commonly used as transmission poles, resulting in the importation of pine poles to cover the deficit, hence the need for this study. The natural durability of <em>Eucalyptus alba</em> and <em>Eucalyptus robusta</em> in the Coastal Savanna Zone (CSZ) and Moist Semi-Deciduous Forest Zone (MSDFZ) was tested using white rot fungus (<em>Coriolopsis polyzona</em>) under an accelerated laboratory test. The results indicated significant variations in the mass lossess be-tween trees in the two vegetation zones. The sapwood and outer heartwood of the <em>E. alba</em> tree species of CSZ recorded the highest mass losses of 41.21 % and 20.79 %, respectively, compared to the <em>E. robusta</em> trees felled from MSDFZ that recorded mass losses of 32.3 % and 5.42 %, respectively. Also, the outer heart- wood and inner heartwood of the <em>E. robusta</em> MSDFZ felled trees were highly resistant (5.42 % and 6.99 %). CSZ wood species were less naturally resistant to <em>C. polyzona</em> attack than those harvested from MSDFZ, which appeared to be less susceptible and more naturally resistant to decay by <em>C. polyzona</em>. Both species are feasible for use as transmission line poles; however, trees from both ecological zones would need chemical preservatives to improve their service life, especially for outdoor applications.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"26 ","pages":"Article e02414"},"PeriodicalIF":2.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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