2647 research outputs found
Sort by
Time series and ensemble models for forecasting Tanzanian banana crop yield under various effects of Climate change
Get PDFAmid escalating global worries about climate change’s impact on agriculture, this study thor
oughly explores how climate shifts might affect Tanzania’s vital bananas. The study employed
a multiple regression model to analyze the correlation between bananas and key climate vari
ables in Tanzania, the results showed gradual decrease in bananas. Additionally, the study
utilized two powerful global sensitivity analysis methods, Sobol’ Sensitivity Indices and Re
sponse Surface Methodology, to comprehensively explore the sensitivity of bananas to climate
variables. So, these methods showed that minimum temperature, precipitation and soil moisture
have the most impact on bananas and affect the crop’s production variability. Furthermore, un
certainty quantification was performed using Monte Carlo simulation, estimating uncertainties
in regression model parameters to enhance the reliability of findings, this indicated substantial
variability in the predictions. Conversely, the study configured time series models such as Sea
sonal ARIMAwithExogenousVariables (SARIMAX),State Space (SS), and Long Short-Term
Memory (LSTM) to forecast bananas in Tanzania under the effects of climate change. Hence,
the study builds predictive frameworks capturing temporal variations and offering glimpses of
future trends. Leveraging historical bananas data and relevant climate variables, an ensemble
model was formulated using a weighted average approach, revealing a future decrease in ba
nanas. This study combines data analysis and advanced models to explore how climate change
affects bananas. Its insights reach beyond farming, impacting stakeholders, policymakers, and
farmers alike. By understanding sensitivities, vulnerabilities, and future trends, this research
informs decisions for sustainable banana production, enhances food security, and encourages
adaptable strategies amidst changing climates
Feature Selection Approach to Improve Malaria Prediction Model’s Performance for High- and Low-Endemic Areas of Tanzania
Get PDFThis research article was published by Springer Nature Link 2024Malaria remains a significant cause of death, especially in sub-Saharan Africa, with about 228
million malaria cases worldwide. Parasitological tests, like microscopic and rapid diagnostic
tests (RDT), are the recommended and standard tools for diagnosing malaria. However, clinical
diagnosis is advised in areas where parasitological tests for malaria are not readily available.
This method is the least expensive and most widely practiced. A clinical diagnosis called
presumptive treatment is based on the patient’s signs and symptoms and physical findings at the
examination. A malaria diagnosis dataset was extracted from patients’ files from four (4)
identified health facilities in Kilimanjaro and Morogoro. These regions were selected to
represent the country’s high- (Morogoro) and low-endemic areas (Kilimanjaro). The dataset
contained 2556 instances and 36 variables. The random forest classifier, a tree-based, was used
to select the most important features for malaria prediction since this classifier was selected for
feature selection because it was robust and had high performance. Regional-based features were
obtained to facilitate accurate prediction. The feature ranking indicated that fever is universally
the most noteworthy feature for predicting malaria, followed by general body malaise, vomiting,
and headache. However, these features are ranked differently across the regional datasets.
Subsequently, six predictive models, using important features selected by the feature selection
method, were used to evaluate the performance of the features. The identified features comply
with the malaria diagnosis and treatment guidelines WHO and Tanzania Mainland provided. The
compliance is observed to produce a prediction model that will fit in the current healthcare
provision system
Extinction and persistence of lumpy skin disease: a deep learning framework for parameter estimation and model simulation
Get PDFThis research article was published by Modeling Earth Systems and Environment Volume 11, (2025)Lumpy Skin Disease (LSD) of cattle, an infectious and fatal viral ailment, poses a significant challenge to the farming sector due to its economic impact. A deterministic Susceptible-Exposed-Infectious-Recovered-Susceptible (SEIRS) model, is utilized in developing a Physics-Informed Neural Network—a deep learning framework for parameter estimation and simulation of LSD dynamics. The deep learning structure is presented alongside an illustration of its application using synthetic data on infectious cattle counts. To accommodate inherent variability in the model, the deterministic version is extended to a stochastic model by introducing environmental noise, assuming that biting rate is the primary source of randomness. Lyapunov second method is used to prove the existence of a unique global positive solution for the stochastic model under specified initial conditions. Subsequently, the stochastic model is employed to establish conditions for both extinction and persistence. Results of the stochastic model simulation indicate potential eradication of the disease when the environmental noise decreases. On the other hand the designed Physics-Informed Neural Network for LSD demonstrates high efficiency in model prediction and parameter estimation especially when few data is available. Analytical results underscore the importance of implementing strategies to reduce biting such as biological control methods as a means to mitigate the transmission of LSD
Nutrient Budgets for Sustained Crop Production in African Soils: Evidence from Potato-Grown Soils in Tanzania
No full textThis research article was published by Sustainable Soil Systems in Global South ,2024Soil fertility is under pressure worldwide due to agricultural intensification to match food demand. In sub-Saharan Africa (SSA), the depletion of soil nutrients is the root cause of the widespread food insecurity. Therefore, there is a need to continually monitor soil nutrient levels to drive policies and management options for sustained food production. Compared to other crops, potato (Solanum tuberosum L.) is increasingly becoming significant for food and economic security in SSA. The crop is, however, a heavy nutrient feeder and withdraws hefty amounts of nutrients from the soil which can interfere with its sustained production. However, very few studies have assessed the soil fertility levels of potato-grown soils in different parts of SSA. This chapter includes a case study report from the investigation of the fertility status and associated physicochemical properties of potato-grown soils in various agro-ecological areas in Tanzania. Soil samples collected from 27 potato farmlands were sampled in nine districts and analyzed for pH, electrical conductivity at 25 °C (EC25), soluble salts (SS), particle size distribution, potassium, phosphorus, iron, nitrogen, zinc, organic matter (OM), and organic carbon (OC) using standard methods. The results revealed significant differences for fertility-related physicochemical properties like EC25 (P = 0.004), (%) SS (P = 0.004), (%) OC (P = 0.018), and (%) OM (P = 0.019) in the soils but there were no significant differences for the fertility status of soils across the different study areas. Significant (P < 0.05) correlations were also observed for different parameters. The study concluded that specific soil characteristics differed significantly while fertility was relatively consistent. These findings serve as a basis for comprehending the existing soil conditions and can inform future strategies for sustainable soil management to ensure optimal nutrient levels to support the continued productivity of potatoes in the region
Risk of Aedes-borne diseases in and around the Tanzanian seaport of Tanga despite community members being more concerned about malaria
No full textThis research article was published by Parasites, Volume 17, (2024)Background Increased global trade, while beneficial economically, can also increase the spread of vector-borne
diseases, particularly those transmitted by Aedes mosquitoes spreading via trade routes. Given the heightened trade-
induced activity at ports of entry, it is particularly crucial to assess the risk of mosquito-borne diseases in these set-
tings. This study compared the risks of Aedes-borne disease in and around the eastern Tanzanian seaport of Tanga.
Methods A 200 m × 200 m grid-based system was used to sample mosquitoes within the port area, and in surround-
ing areas at 2 km, 2.5 km, and 5 km away, between June and December 2023. We characterized mosquito breeding
habitats, collected mosquito larvae using standard dippers and tested susceptibility of raised adult Aedes aegypti
populations to different insecticides. Adult mosquitoes were collected using BG sentinel traps (daytime) and Centers
for Disease Control (CDC) light traps (night-time). Additionally, more than 200 port users and neighboring residents
were surveyed to assess their experiences with and perceptions of mosquito biting and disease risks.
Results There were 2931 breeding sites, with (60.8%, n = 1782) positive for Aedes larvae. The percentage of water-
holding containers infested with Aedes immatures, i.e., the container index (CI), was highest in the port area (66.2%),
and lowest 5 km away (44.6%). The port area also had a greater proportion of temporary breeding sites (64.9%)
than did the surrounding areas. The adult mosquito surveys revealed 20,449 mosquito species including: Culex
quinquefasciatus (56.2%), Mansonia uniformis (38.6%), Ae. aegypti (5.1%), Anopheles gambiae (0.1%), and Anoph-
eles funestus. Ae. aegypti were more abundant in the port area than in the surrounding areas (P < 0.001), whereas
Culex sp., and Mansonia sp., were significantly outside (P < 0.001). Adult Anopheles sp., were found only in the port
area, but Anopheles larvae were found both within and outside the port areas. Tests on Ae. aegypti sp., revealed
susceptibility to bendiocarb and DDT, and resistance to permethrin. Awareness of mosquito-borne diseases
among respondents was high for malaria (64.8%), but low for dengue (26.3%) and Chikungunya (1.7%). Most respond-
ents reported being bothered by mosquitoes mostly at night (53.4%) or in the evening (40.7%). In addition to insecti-
cidal bednets, which are used primarily against malaria, preventive measures for Aedes-borne diseases are limited.
Conclusions This study identified significant potential risk of Aedes species, specifically Ae. aegypti sp., and associated
diseases, but low perception of risk and inadequate personal protection measures in the study area. This low percep-
tion of risk highlights the need to improve public knowledge of the transmission and control of Aedes-borne diseases
The lethal effect of soap on Schistosoma mansoni cercariae in water
Get PDFThis research article was published by PLOS Neglected Tropical Diseases, 2024Background
Schistosomiasis is a parasitic disease which is spread through skin contact with water containing Schistosoma cercariae. Drug treatment has been the main control method, but it does not prevent reinfection. The use of soap can be a complementary measure to reduce transmission. Therefore, this study investigates the quantitative effect of different soaps on the mortality of Schistosoma mansoni cercariae.
Methodology
Four soaps including two powder soaps (Kleesoft and Omo) and two bar soaps (B29 and Rungu) which are used in a schistosomiasis-endemic Tanzanian village were studied. S. mansoni cercariae were exposed to powder soaps of 0 (control), 10, 50, 75, 100 and 1000 mg/L and to bar soaps of 0 (control), 100, 500 and 1000 mg/L. The highest concentration of 1000 mg/L was selected based on the laboratory-estimated average soap concentration during handwashing. Cercariae were observed under a microscope after 0, 5, 15, 30, 45 and 60 minutes of exposure to determine their survival.
Conclusions
All four soaps can kill S. mansoni cercariae and this lethal effect was related to soap concentration and exposure time. At the highest concentration of 1000 mg/L, all cercariae were dead at 5 minutes post-exposure with two powder soaps and Rungu, while 100% cercarial death was achieved between 5 minutes to 15 minutes for B29. Almost all cercariae survived after being exposed to 10 mg/L powder soaps and 100 mg/L bar soaps for 60 minutes. Powder soaps were more lethal than bar soaps. Considering the widely varying concentrations of soap during real-world hygiene activities and the necessity for a very high soap concentration to eliminate all cercariae in a short 5-minute exposure, providing the efficacy of soap in preventing schistosomiasis becomes challenging. Future studies should investigate whether soap can influence alternative mechanisms such as making cercariae unable to penetrate the skin, thereby providing protection
Culex quinquefasciatus mosquito avoids ovipositing in habitats with the annual fish (Nothobranchius neumanni) in Tanzania
Get PDFThis research article was published by Aquatic Ecology, Volume 58, 2024Mosquitoes are known to choose oviposition habitats actively based on their suitability for survival of their offspring. They thus avoid laying eggs in dangerous habitats with aquatic predators through detection of their cues. Visual, tactile, and chemical cues emitted by certain predators have been shown to reduce oviposition in some mosquitoes, which in turn may affect their adult population sizes. However, those tests tend to be limited to species from temperate regions. Moreover, mosquito oviposition response to predator cues have been shown to be predator specific, but this has not been investigated for many potential predators worldwide. In the African subtropics, temporary ponds can be important mosquito breeding habitats and the same habitats are also used by a group of specialized killifish that can survive dry periods using drought resistant eggs. Although they are reported as mosquito predators, it is unknown whether mosquitoes actively avoid laying eggs in ponds with annual killifish. We investigated this using the mosquito Culex quinquefasciatus and the free and caged killifish Nothobranchius neumanni in the outdoor mesocosm experiments in Tanzania. We found that Cx. quinquefasciatus had 71% lower oviposition in mesocosms with free swimming killifish and 68% lower oviposition in mesocosms with caged killifish. We conclude that predator-released chemical cues alone are enough to explain the observed responses. If the cues can be isolated and chemically identified can be developed into a biological mosquito control strategy and used to safeguard public health in areas where mosquito borne diseases are endemic
Experimental Prosopis juliflora Management Practices and Grassland Restoration in Three Eastern African Countries
Get PDFThis research article was published by Plant Health Cases, 2024Prosopis juliflora, a native tree species of Central and northern South America, was introduced in degraded habitats in Eastern Africa as a wind break, and as a source of fodder, fuel, and timber. P. juliflora has a high drought tolerance and has become a highly invasive tree or shrub, spreading rapidly, and transforming socio-economic systems. It negatively impacts livelihoods in many ways, including reduced income in pastoralist-dominated regions once coverage is above a certain invasion level. Management of P. juliflora is needed to restore ecosystem services, such as biodiverse grassland that provides fodder and sequesters carbon. In order to investigate which are the most effective and economically efficient management practices, a 3-year study was conducted in Ethiopia, Kenya, and Tanzania, three countries with savanna and grassland that have been invaded by P. juliflora. The management treatments being tested were: manual uprooting; cutting the stumps and applying herbicide; and basal bark herbicide treatment. Alongside these treatments, restoration interventions aimed at restoring natural vegetation were also tested, and these were: creating divots; creating divots + mulching with hay; and creating divots + mulching with hay + grass seed sowing. The control methods were all highly effective in killing P. juliflora, with methods to remove all above-ground biomass (manual and cut stump) resulting in a more productive and diverse surrounding vegetation than the basal bark herbicide treatment. The effect of the restoration interventions on vegetation composition was small, suggesting that species were re-established mostly from the soil seed bank. This case presents some of the methods and results of the study
Prevalence of Taenia solium cysticercosis in domestic pigs following albendazole deworming intervention in rural communities of Mbulu district, Tanzania
Get PDFThis research article was published by Food and Waterborne Parasitology /Volume 36, September 2024Taeniosis and cysticercosis are infections caused by cestodes, Taenia solium is among them. T.solium neurocysticercosis accounts for 30% of acquired epilepsy in human in developing countries. This study was carried out to determine the prevalence of cysticercosis among domestic pigs in Mbulu district following deworming intervention. The study was conducted among three rural communities monitoring community intervention in Mbulu district between March 2020 and September 2021. Live pigs were diagnosed by lingual examination for the presence of T. solium cysticerci, and pig-rearing practices were recorded. Logistic regression was performed to determine the role of risk factors on pig infection outcome. We conveniently sampled 510 pigs; 267 (52.4%) were sampled in the year 2020 and 243 (47.6%) in 2021. All pigs were examined by lingual examination for the presence of pork tapeworm larvae, and 43 (8.4%) pigs were found to be infected. Twenty-one (48.8%) of the infected pigs were males and 22 (51.2%) were females, and the overall annual prevalence of tapeworm larvae was 9% and 7.8% for 2020 and 2021, respectively. The pigs were twice more likely to be found infected during the rainy season compared to the dry season in 2020 (OR = 2.27, 95%CI of 1.16–7.22). The reported pig-rearing practices were free-range, penned, and tethered, 141 (52.8%), 64 (24%), and 62 (23.2%), respectively. Of the 94 visited households in 2020, 78 (83%) reported drinking water without boiling, and 59 (62.8%) household leaders reported having heard about taeniosis/cysticercosis. The prevalence of cysticercosis among domestic pigs in this study was high, with seasonal variations. Despite the ongoing national school deworming and community deworming program, there was no significant change in the prevalence of cysticercosis over two consecutive years. The reported pig infections imply fecal-oral transmission with humans tapeworm eggs released from infected humans. Most households reported consuming unboiled drinking water that might be contaminated. Integrating pig vaccination and deworming, health education and school or community deworming along with improved pig management practice and general community water sanitation hygiene (WASH) are recommended to reduce the burden of pork tapeworm in the study communities
The impacts of land use and climate change on Simiyu river discharge and the riverine sediment dynamics flowing towards lake Victoria
Get PDFA Thesis Submitted in the Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Hydrology and Water Resources Engineering of the Nelson Mandela African Institution of Science and TechnologyThis study aimed to trace the dominant sources of riverine sediments and assess climate
change's current and future impacts on the river discharge at the critical agroecological region
of the Simiyu catchment. Geochemical fingerprinting of the riverbed sediments and potential
sediment sources were compared using a Bayesian mixing model (MixSIAR) to attribute the
dominant riverine and land-use sources to the Simiyu Mainstem. The mixing model outputs
showed that the Simiyu tributary was the dominant sediment source to the Simiyu Mainstem
with 63.2%, while the Duma tributary accounted for 36.8%. Cultivated land was shown to be
the main land-use source of riverine sediment, accounting for 80 % and 86.4% in the Simiyu
and Duma sub-tributaries, respectively, followed by channel banks with 9% in both sub tributaries. The Soil and Water Assessment Tool (SWAT) under RCPs 4.5, 6.0, and 8.5 were
also used to project the impacts of climate change on river discharge throughout 2030–2060.
The selected three General Circulation Models (GCMs) predicted an increase in the annual
average temperature of 1.4°C in 2030 to 2°C in 2060 and an average reduction of 7.8% in
rainfall, which causes a decrease in river discharge. The simulated river discharge from the
hydrological model under RCPs 4.5, 6.0 and 8.5 revealed a decreasing trend in annual average
discharge by 1.6 m3s−1 from 5.66 m3s-1in 2019 to 4.0 m3s-1in 2060. Arbitrary, there will be an
increase in frequent flood occurrence in the future (2030–2060) compared to the current period
(1990–2019), with extreme discharges of 451.3 m3s−1and 232.8 m3s−1 at exceedance
probabilities of 0.01% and 99.99%, respectively. The demonstrated application of sediment
source tracing provides an important pathway for quantifying the dominant sediment sources
in the rivers flowing towards Lake Victoria. This information is vital for designing catchment wide management plans that should focus on buffering the projected decreases in discharge,
reducing soil erosion and sediment delivery from farming areas to the river networks, and
ultimately supporting food security and water quality in the Lake Victoria Basi