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A deep learning model for early detection of maize diseases in Tanzania
Get PDFAgriculture is considered the backbone of Tanzania’s economy, with more than 60% of residents
depending on it for their livelihood. Maize is the main and dominating food crop in the country,
accounting for 45% of all farmland produce. Inevitably, its production is affected by diseases that,
if detected early, could be easily treated. Maize Streak Virus (MSV) and Maize Lethal Necrosis
(MLN) are commonly reported diseases that are often detected too late by farmers. This raised the
need for a sophisticated method for early detection of these diseases to enable timely treatment.
This study investigated the potential of developing a deep-learning model for the early detection
of maize diseases in Tanzania. Imagery datasets were used for model training, they were collected
through physical observation with the help of a plant pathologist from three regions of the country;
Arusha, Kilimanjaro, and Manyara. Two models, a Convolutional Neural Network (CNN) and a
Vision Transformer (ViT), were developed from scratch and classified into four classes: Healthy,
MLN, MSV, and WRONG. The results revealed that the ViT model outperformed the CNN model,
achieving validation accuracies of 0.931 and 0.9096 respectively. Despite the superior
performance of the ViT model, the CNN model was selected for deployment in a mobile-based
application due to its smaller size, lower memory, and small computational requirements. A
quantitative research method using a survey questionnaire was employed to gather requirements
for system development and validation. Validation of the model's performance through
questionnaires administered to farmers and agricultural experts, yielding highly positive feedback.
This enthusiastic reception highlights the potential impact of the developed application on
improving early disease detection and enhancing maize productivity in Tanzania. Empowering
stakeholders of agriculture to identify more effective methods of managing them before serious
harm is done. Consequently, custodians of agriculture, such as the Ministry of Agriculture,
organizations, and other companies, will have the potential to detect maize diseases early,
henceforth adding up to the increase in the Gross Domestic Product (GDP) and guaranteeing the
country’s food security
Flea Burden on Rodents and Its Associated Determinants in Plague-Endemic Localities of Karatu District, Tanzania: A Cross-Sectional Study
Get PDFThis research article was published by Public Health Challenges Volume 3, 2024Background
Fleas infest rodents and other small mammals, serving as vectors for zoonotic diseases such as plague. This study investigates the flea burden on rodents and its associated determinants within the plague-endemic localities of Karatu district, Tanzania.
Methods
A repeated cross-sectional design was employed to capture rodents with Sherman traps in farmland, peridomestic area, bush land, and forest buffer zones across the wet and dry seasons of 2022 in plague and nonplague foci villages. Captured rodents were anaesthetized and thoroughly brushed to collect fleas, which were then identified using a dichotomous key.
Results
A total of 291 rodents (9 species) were captured, from which 190 fleas (4 species) were collected. The collected fleas were Dinopsyllus lypusus (46.32%), Ctenophthalmus sp (26.84%), Xenopsylla brasiliensis (16.32%), and Xenopsylla cheopis (10.53%). Approximately 38.42% of fleas were found on Mastomys natalensis, 22.63% on Lemniscomys striatus, and 18.42% on Rattus rattus. High flea abundance was recorded in farmland and peridomestic areas. The specific flea index (SFI) of X. cheopis on R. rattus was 1.0 in plague foci and <0.5 in nonplague foci. A generalized linear model revealed significant influences of rodent species, season, habitats, rodent weight, sex, and plague locations on flea abundance. Significant variation was observed between rodent sexes (p = 0.009), and a weak positive correlation existed between rodent weight and flea abundance (R = 0.17, p < 0.05).
Conclusion
Villages in plague foci exhibited higher abundances of fleas in comparison to nonplague foci villages. The SFI results for X. cheopis on rats in both types of villages did not surpass critical thresholds. Factors such as dry season, farmlands, and rodent characteristics influenced flea abundance on rodents in the study area
Review of Sources of Uncertainty and Techniques Used in Uncertainty Quantification and Sensitivity Analysis to Estimate Greenhouse Gas Emissions from Ruminants
Get PDFThis research article was published by Sustainability Volume 16, 2024Uncertainty quantification and sensitivity analysis are essential for improving the modeling and estimation of greenhouse gas emissions in livestock farming to evaluate and reduce the impact of uncertainty in input parameters to model output. The present study is a comprehensive review of the sources of uncertainty and techniques used in uncertainty analysis, quantification, and sensitivity analysis. The search process involved rigorous selection criteria and articles retrieved from the Science Direct, Google Scholar, and Scopus databases and exported to RAYYAN for further screening. This review found that identifying the sources of uncertainty, implementing quantifying uncertainty, and analyzing sensitivity are of utmost importance in accurately estimating greenhouse gas emissions. This study proposes the development of an EcoPrecision framework for enhanced precision livestock farming, and estimation of emissions, to address the uncertainties in greenhouse gas emissions and climate change mitigation
Solvothermal liquefaction of orange peels into biocrude: An experimental investigation of biocrude yield and energy compositional dependency on process variables
Get PDFThis research article was published by Bioresource Technology Volume 391, 2024The efficient valorization of biomass for energy-derived biocrudes is essential for effective waste management. However, the production of biocrudes with high energy and reduced oxygen contents during the liquefaction process requires further insight. Therefore, the impact of reaction temperature, residence time, and ethanol: acetone on the energy compositions and bioproduct’s yield enhancement were investigated. The biocrudes obtained were characterized using elemental analysis, GC–MS, FTIR, GPC and TGA to understand the effects of process parameters on the biocrudes’ compositions. An improved HHV (38.18 MJ/kg) and lower O/C ratio (0.11) were obtained at 430 °C, 35 min and 50% ethanol with a significant improvement in the enhancement factor, deoxygenation, and percentage hydrogenation of 2.63, 36.88%, and 77.87%, respectively. The presence of ketones, hydrocarbons, phenolics and aromatics of 23.74, 4.28, 37.20 and 17.81% respectively indicate the potential of the obtained biocrude as renewable energy sources upon further upgrading
Characterization of population connectivity for enhanced cross-border surveillance of yellow fever at Mutukula and Namanga borders in Tanzania
Get PDFThis research article was published by IJID Regions Volume 13, December 2024Objectives
Yellow fever (YF) remains a public health threat in Sub-Saharan Africa and South America, with an estimated 200,000 cases and 30,000 deaths annually. Although the World Health Organization considers Tanzania to be at low risk for YF because no YF cases have been reported, the country remains at alert to importation of the virus due to ecological factors and high connectivity to high-risk YF areas in other countries. This study aimed to identify points of interest with connectivity to high-risk YF areas to guide preparedness efforts in Tanzania.
Methods
Using the Population Connectivity Across Borders (PopCAB) toolkit, the Nelson Mandela African Institution of Science and Technology (Department of Health and Biomedical Sciences), in collaboration with the Tanzania Ministry of Health and the Centers for Disease Control and Prevention, implemented 12 focus group discussions with participatory mapping in two high-risk borders of Mutukula and Namanga.
Results
Participants identified 147 and 90 points of interest with connectivity to YF risk areas in Kenya and Uganda, respectively. The identified locations are important for trade, fishing, pastoralism, tourism, health-seeking, agriculture, mining, religious activities, education, and cross-border marriages.
Conclusions
The Tanzania Ministry of Health used the results to update cross-border surveillance and risk communication strategies and vaccination guidelines to prevent the importation of YF into Tanzania
Seroprevalence and risk factors for brucellosis amongst livestock and humans in a multi-herd ranch system in Kagera, Tanzania
Get PDFThis research article was published by Infectious Diseases: Epidemiology and Prevention Volume 12 - 2024Background: Brucellosis remains a significant health and economic challenge for livestock and humans globally. Despite its public health implications, the factors driving the endemic persistence of Brucella at the human-livestock interface in Tanzania remain poorly elucidated. This study aimed to identify the seroprevalence of Brucella infection in livestock and humans within a ranching system and determine associated risk factors for disease endemicity.
Methods: A cross-sectional sero-epidemiological study was conducted in 2023 in Tanzania’s Karagwe District, involving 725 livestock (cattle, goats, sheep) from 10 herds and 112 humans from associated camps. Seroprevalence was assessed using competitive ELISA while epidemiological data were collected via questionnaires. Generalized Linear Models and Contrast Analysis were used to identify risk factors for infection.
Results: Overall seroprevalence was 34% in livestock and 41% in humans. Goats exhibited the highest prevalence (69.2%), while cattle had the lowest (22.6%). Mixed-species herds (Odds Ratio, OR = 2.96, CI [1.90–4.60]) and small ruminants-only herds (OR = 6.54, CI [3.65–11.72]) showed a significantly higher risk of seropositivity compared to cattle-only herds. Older cattle (OR = 5.23, CI [2.70–10.10]) and lactating females (OR = 2.87, CI [1.78–4.63]) represented significant risks for brucellosis in livestock. In humans, close contact with animals (OR = 7.20, CI [1.97–36.31]) and handling animals during parturition or aborted fetuses (OR = 2.37, CI [1.01–5.58]) were significant risk factors. Notably, no spatial association was found in seroprevalence between herds and nearby human communities.
Conclusion: The lack of spatial correlation between livestock and human seroprevalence suggests complex transmission dynamics, potentially involving endemic circulation in livestock and human infections from multiple sources of exposure to livestock. This study highlights the need for comprehensive zoonotic risk education and targeted intervention strategies. Further research is crucial to elucidate transmission pathways and improve Brucella infection control. This includes developing robust methods for identifying infective species and implementing effective strategies to mitigate Brucella infection in endemic regions
Advances in metal–organic frameworks as adsorbents, photocatalysts and membranes: a new frontier in water purification
Get PDFThis research article was published by Discover Water, Volume 4,(2024)Water is an essential and irreplaceable necessity for life on earth, sustaining ecosystems, nourishing agriculture and vital for human survival. However, increasing population and industrialization has exacerbated water scarcity and pollution. The Sustainable Development Goal 6 focuses on clean water and sanitation for all; thus, water purification and conservation are key priorities globally. Rampant pollution of water sources by emerging bio-recalcitrant contaminants, often deviant of conventional treatment methods, necessitates new approaches to water treatment. In this regard, metal organic frameworks (MOFs) are gaining prominence and offer solutions in versatile applications due to their unique structural characteristics and tunable properties. This review provides a comprehensive analysis of MOFs, covering their diverse structures, types, synthesis methods and characterization techniques. We explore the application of MOFs in water purification, as adsorbents, photocatalysts, and in membrane separation. The mechanism of operation of MOFs in each application is critically evaluated. The effect of the water treatment methods on energy consumption has also been investigated. We propose that for MOFs application in water treatment to be competitive and sustainable, there is need to address key issues such as synthesis of highly selective MOFs, recovery and reuse, scalability (pilot and industrial scale), and integration with existing water treatment technologies to create synergy. We provide future perspectives on these aspects.
“Tree of life”: how baobab seed-derived biochar could lead to water safety for underprivileged communities through heavy metal (Fe) removal – SDG 6
Get PDFThis research article was published by Environmental Science Advances 2024The abnormally gigantic baobab tree (Adansonia digitata) is often referred to as the “Tree of Life” due to its
ability to provide food, water, shelter, and traditional medicine for both humans and animals in arid regions.
This special tree is a landmark of Africa's savanna and has attracted the attention of the global research
community. This study investigated the potential of biochar derived from baobab seeds for the removal
of metallic ions from groundwater. The biochar, prepared at 700 °C, exhibited a unique surface
morphology with deep voids and varied structures, suggesting increased surface area and favorable
conditions for adsorption. SEM-EDX analyses confirmed the elemental composition, with carbon being
the predominant element. Furthermore, XRD analysis indicated an amorphous structure, enhancing
adsorption capacity for heavy metal ions. Additionally, BET analysis revealed a significant surface area
(1386.704 m2 g−1
) and well-defined pores, emphasizing the material's potential for metallic ion removal.
The metallic ion of choice for this research was Fe because of its abundance in the study area and the
community's need for affordable technology for discoloration of reddish-brown groundwater caused by
Fe ion presence. In the batch mode equilibrium studies, the effect of pH, contact time, adsorbent
particle size, adsorbent dose, solution temperature, and initial metal ion concentration was investigated.
Optimal pH metallic ion removal occurred under neutral pH conditions, with higher removal efficiency
observed at increased contact time (up to 120 min) and adsorbent doses. Adsorption isotherm modeling
using Langmuir and Freundlich models indicated favorable adsorption, with the Freundlich model
providing a slightly better fit. In conclusion, baobab seed-derived biochar demonstrated promising
potential as an efficient and sustainable adsorbent for metal ion removal from groundwater. Further
exploration, including the development of activated carbon and field applications, is recommended for
a comprehensive understanding and practical optimization of this material's capabilities for metal ion
removal
Developing an Agent-based Model for Evaluating the Effectiveness of Malaria Interventions in Nanyumbu and Masasi Districts, Tanzania
Get PDFThis research article was published by Indian Journal of Science and Technology, Volume: 17, 2024Objective : Agent-based models and simulation (ABMS) can be utilized to understand the dynamism of transmission and the effect of interventions. We evaluated using ABMS, the efficacy of insecticide-treated bednets (ITNs) at different coverage levels and quality of houses for control of malaria in Masasi and Nanyumbu districts, Tanzania. Methods: The model was developed and simulated in Anylogic software with mosquitoes, humans, and the environment along with their attributes as agents. Using field data, buildings of different qualities were created to be human environment, and ITN use was assigned to respective human agents. Shapefiles were imported into the built-in global imaging system map in Anylogic for better placement of buildings using their coordinates, and coordinates of streams extracted from the study area map were used to allocate the aquatic environment of the mosquito agents. ITNs coverage scenarios of 16%, 40%, 64%, and 80% were simulated. The model was simulated for 90-day period and a model time-step was set to a day. The primary outcome was the prevalence of human agents with malaria infection at the end of the 90-day simulation period. Results: At the end of the 90-day simulation period and initial ITNs coverage of 16% (257/1607), the prevalence of malaria infection was 15.4% (248/1607). When the coverage was increased to 40%, 64%, and 80% malaria prevalence declined to 15.1% (242/1607), 14.1% (227/1607), and 13.9% (223/1607), respectively. ABMS clearly indicated that an increase in ITNs coverage was associated with a decline in the prevalence of infected humans and mosquito population in consistency with the field data. Novelty: This work is unique in a sense that it incorporated the data on house quality which has direct impact in malaria transmission
Techno-economic evaluation of transesterification processes for biodiesel production from low quality non-edible feedstocks: Process design and simulation
Get PDFThis research article was published by ELSEVIER, Volume 297, 2024The global demand for fossil fuels has led to increased pollutant emissions and depleted fossil fuel resources. Biodiesel, a fossil fuel alternative, is widely produced via transesterification. This study assesses the techno-economic performances of three transesterification processes (alkaline, acid, and CaO catalytic) for biodiesel production from low-quality non-edible feedstocks. The study explores effects of elevated free fatty acids (FFAs) and oil/ethanol flow rates on these processes, focusing on their impact on yield, purity, economics and energy aspects. Aspen Plus® V10 software was used for simulations. Despite meeting international biodiesel standards, significant technical and economic variations exist among the processes. The acid catalytic process exhibits energy requirements surpassing those of alkaline and CaO catalytic processes by over 29.58%, leading to operational costs exceeding those of CaO catalysis by 13.11%. The study establishes CaO catalysis as the most feasible option due to its simplicity, adaptability, and substantial energy and cost reductions. By introducing a closed-loop blending setup configuration, the study reveals that CaO catalysis outperforms alkaline and acid catalysis, achieving 11.59% cost reduction and 13.31% energy decrease in closed-loop configurations. The overall results highlight the potential of non-edible feedstocks in biodiesel production for a more environmentally friendly and sustainable energy future