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Item The COVID-19 pandemic and its impacts on diet quality and food prices in sub-Saharan Africa(Public Library of Science (PLOS), 2023) Ismail, Abbas; Madzorera, Isabel; Apraku, Edward A.; Tinkasimile, Amani; Dasmane, Dielbeogo; Zabre, Pascal; Ourohire, Millogo; Assefa, Nega; Chukwu,Angela; Workneh, Firehiwot; Mapendo, Frank; Lankoande, Bruno; Hemler, Elena; Wang, Dongqing; Abubakari, Sulemana W.; Asante, Kwaku P.; Baernighausen, Till; Killewo, Japhet; Oduola, Ayoade; Sie, Ali; Soura, Abdramane; Vua, Said; Smith, Emily; Berhane, Yemane; Fawz, Wafaie W.Background Sub-Saharan Africa faces prolonged COVID-19 related impacts on economic activity, livelihoods and nutrition, with recovery slowed down by lagging vaccination progress. Objective This study investigated the economic impacts of COVID-19 on food prices, consumption and dietary quality in Burkina Faso, Ethiopia, Ghana, Nigeria, and Tanzania. Methods We conducted a repeated cross-sectional study using a mobile platform to collect data from July-December, 2021 (round 2). We assessed participants’ dietary intake of 20 food groups over the previous seven days and computed the primary outcome, the Prime Diet Quality Score (PDQS), and Dietary Diversity Score (DDS), with higher scores indicating better quality diets. We used generalized estimating equation (GEE) linear regression models to assess factors associated with diet quality during COVID-19. Results Most of the respondents were male and the mean age was 42.4 (±12.5) years. Mean PDQS (±SD) was low at 19.4(±3.8), out of a maximum score of 40 in this study. Respondents (80%) reported higher than expected prices for all food groups. Secondary education or higher (estimate: 0.73, 95% CI: 0.32, 1.15), medium wealth status (estimate: 0.48, 95% CI: 0.14, 0.81), and older age were associated with higher PDQS. Farmers and casual laborers (estimate: -0.60, 95% CI: -1.11, -0.09), lower crop production (estimate: -0.87, 95% CI: -1.28, -0.46) and not engaged in farming (estimate: -1.38, 95% CI: -1.74, -1.02) were associated with lower PDQS. Conclusion Higher food prices and lower diet quality persisted during the COVID-19 pandemic. Economic and social vulnerability and reliance on markets (and lower agriculture production) were negatively associated with diet quality. Although recovery was evident, consumption of healthy diets remained low. Systematic efforts to address the underlying causes of poor diet quality through transforming food system value chains, and mitigation measures, including social protection programs and national policies are critical.Item Chicken productivity under improved health care and management practices in Dodoma region, Tanzania(University of Nigeria, Nsukka, 2023) Chota, Andrew; Ngongolo, Kelvin; Ngumbi, Anna; Mmbaga, Naza; Msuta, GilbertRaising chickens is an important activity in many resources constrained households in developing countries, as it is an important source of economic resilience as well as nutrition and food security. Despite its importance, the poultry industry faces many difficulties, including diseases due to low biosecurity and a lack of knowledge on proper management. A cross-sectional questionnaire survey was conducted to study the management practices that influence the performance of chickens in the households raising them in the Dodoma region of Tanzania. The results showed that 89% of respondents were vaccinating their chickens against diseases like Newcastle, fowlpox, infectious bursal disease and salmonellosis. However, many chicken farmers had incorrect information on the vaccination programs, including the frequency of vaccination and the timing of vaccinations, versus the provision of drugs for prophylactic purposes. The results showed that 29.5% of the farmers vaccinated weekly and 63.5% provided prophylactic drugs weekly. Furthermore, raising different types of chickens (OR = 1.45; p<0.01), frequency of vaccinations, (OR = 1.23; p<0.04), larger flocks of chickens (OR = 1.7; p<0.01), small number of chickens per drinker (OR = 1.64; p<0.05), and per feeder (OR = 2.4; p<0.05) were management factors associated with positive chicken performance in terms of growth rate, egg production and weight gain. It is recommended that the farmers are equipped with the necessary information on best management practices like vaccination regimes, prophylaxis timing and proper ratios of chickens per feeder and drinker.Item Machine learning based prospect targeting: A case of gold occurrence in central parts of Tanzania, East Africa(Elsevier, 2024) Gawusu, Sidique; Mvile, Benatus Norbert; Abu, Mahamuda; Kalimenze, John DesderiusSoil geochemical analyses from central Tanzania reveal significant gold (Au) values, highlighting the potential for further exploration in the region. This study employs ensemble machine learning models—XGBoost-RF, XGBoost-SVM, and XGBoost-ANN—to enhance predictions of Au distribution. Among these, the XGBoost-ANN model showed the highest accuracy during the training phase, achieving a Mean Absolute Percentage Error (MAPE) of 1.275, a Root Mean Square Error (RMSE) of 0.031, an R² of 0.999, and a Pearson Correlation Coefficient (PCC) of 0.999. However, its performance declined in the testing phase with a MAPE of 0.0668 and an RMSE of 0.2491, indicating reduced predictiveness on new data. Spatial analyses using Global and Local Moran's I tests revealed no significant global spatial autocorrelation but identified localized clusters of high and low Au concentrations. Specific areas showed significant spatial dependence, enhancing our understanding of the complex geospatial distribution of Au. These findings support the combined use of predictive modeling and spatial statistical methods to refine mineral exploration strategies, highlighting the value of advanced analytics in identifying promising exploration targets.Item Optimal Control of Droughts, Diseases and Retaliatory Killing in Prey-Predator Systems(SCIK Publishing Corporation, 2023) Charles, Raymond; Makinde, Oluwole Daniel; Kung’aro, MonicaIn this article, we describe an application of optimal control theory to evaluate the success of controls on the dynamics of prey-predator systems of the Serengeti ecosystem, which includes wildebeest, zebra, and lion. This is accomplished by suggesting control variables like education (to prevent retaliatory killing), dam construction (to prevent drought), and treatment (to combat infections). Maximizing population density is the major objective. For this aim, the Pontryagin’s maximum principle has been applied. The optimal control are characterized in terms of optimality system and solved numerically for several scenarios. Results shows that multiple optimal control measures is the most effective strategy in management of wildlife populations. Results also shows that, if the ecosystem management decide to use a single control, the construction of dams is the best control in maximizing the objective function.Item Performance of IRI 2016 model in predicting total electron content (TEC) compared with GPS-TEC over East Africa during 2019–2021(Springer Science and Business Media LLC, 2024) Sulungu, Emmanuel D.This study evaluated the applicability of IRI-2016 model in predicting GPS TEC using the monthly means of the fve (5) quiet days for equinoxes and solstices months. GPS-derived TEC data were obtained from the IGS network of ground based dual frequency GPS receivers from three stations [(KYN3 0.53° S, 38.53° E; Geom. Lat. 3.91.63° S), (MBAR 0.60° S, 30.74° E; Geom. Lat. 2.76° S) and HOID 1.45° S, 31.34° E; Geom. Lat. 3.71° S]. All the three options for topside Ne of IRI-2016 model and ABT-2009 for bottomside thickness have been used to compute the IRI TEC. The results were compared with the GPS TEC measurements. Correlation Coefcients between the two sets of data, the Root-Mean Square Errors of the IRI-TEC from the GPS-TEC, and the percentage RMSE of the IRI-TEC from the GPS-TEC have been computed. In general, the IRI-2016 model underestimated GPS-TEC during the nighttime, whereas the model overestimated GPS-TEC values during the daytime. At most of the stations and during all seasons where data were available, correlation coefcient was above 0.9, which is quite strong. The variation of O/N2 ratio may potentially be the cause of the IRI TEC deviation from the GPS TEC. This variation arises from lower thermosphere plasma drift that moves upward.Item Preparation and characterization of poly (lactic acid)-chitosan blend fibrous electrospun membrane loaded with bioactive glass nanoparticles for guided bone/tissue regeneration(Elsevier BV, 2024) Bahati, David; Bricha, Meriame; Semlali, Abdelhabib; El Mabrouk, KhalilIn this study, bioactive fibrous membranes composed of poly (lactic) acid (PLA), chitosan (CHS), and strontium-doped bioactive glass nanoparticles (BG) were produced via electrospinning technique using a triple solvent system and characterized via thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), static contact angle (CA), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). All fiber samples exhibited consistent one-step thermal degradation profiles, regardless of BG content, and the intended BG contents in the membranes ware confirmed. The addition of 3% w/w CHS to form PLA-CHS blend lowered the glass transition temperature (Tg) by 1.62 °C. FTIR analysis validated the presence of CHS in the PLA-CHS blend fibers through the appearance of a low-intensity broad peak around 1658–1566 cm⁻1, indicating primary amide functional groups. Incorporating 3% w/w CHS reduced water contact angle by 7% and decreased fiber diameter by 57%. Wettability improved with increasing BG content, as confirmed by SEM images showing well-dispersed BG nanoparticles within the fibers. After 35 days of immersion in simulated body fluid (SBF), a substantial layer of hydroxyapatite (HA) with a Ca/P ratio resembling that of natural human bones coated the BG particles and fibers. The membranes demonstrated excellent cell adhesion capabilities, especially in the PLA_3%CHS and PLA_3% CHS_5% BG configurations, with minimal cellular toxicity compared to a well-known cell-killing agent, highlighting their biocompatibility. Incorporating chitosan and strontium-doped bioactive glass nanoparticles into PLA blends positively influenced cell viability and proliferation, emphasizing the enhanced cellular response resulting from surface modifications. These properties make these fibrous membranes promising for guided bone and tissue regeneration applications.Item A finite difference study of radiative mixed convection MHD heat propagating Casson fluid past an accelerating porous plate including viscous dissipation and Joule heating effects(Elsevier BV, 2024) Reddy, B. Prabhakar; Matao, P.M.; Sunzu, J.M.A finite difference numerical simulation scrutiny is executed to evaluate the combined impacts of heat generation, buoyancy forces, viscous dissipation and Joule heating in unsteady hydro-magnetic mixed convective chemically reactive and radiative Casson fluid flowing along an exponentially accelerating permeable vertical plate engrossed in a porous media by considering ramp surface concentration and temperature. The dimensionless non-linear coupled PDEs describing the flow model are dealt numerically by adopting the competent implicit Crank-Nicolson finite difference procedure. The variance of velocity, temperature, and concentration distributions are exposed via graphical representations due to the dissimilarity of the flow restrained parameters. Computational outcomes of the skin-friction, Nusselt and the Sherwood numbers are portrayed in the tabular pattern. The final outcomes of the research exposed that the impacts of thermal radiation, viscous dissipation, and heat production parameters enlarges the temperature and velocity distributions. The fluid motion deflates for growing Casson parameter and magnetic field intensity. The rising chemical reaction parameter suppresses the concentration and velocity distributions. Very importantly it is distinguished that fluid momentum, temperature, and concentration are quicker in the instance of isothermal plate temperature than ramp wall temperature. This kind of research may find specific industrial and medical utilizations such as glass manufacturing, crude oil purification, lubrication, paper production, blood transport study in cardiovascular design, etc.Item The capability of Artificial Neural Networks as a model for predicting Total Electron Content (TEC): A review(The Open University of Tanzania, 2023) Sulungu, EmmanuelThe results of investigations from a complete analysis of ANN application on Total Electron Content (TEC) prediction are presented in this paper. TEC is important in defining the ionosphere and has many everyday applications, for example, satellite navigation, time delay and range error corrections for single frequency Global Positioning System (GPS) satellite signal receivers. The total electron content (TEC) in the ionosphere has been measured using GPS. GPS are not installed in every point on the earth to make global TEC measurements possible. As a result, it is crucial to have certain models that can aid to get data from places where there is not any in order to comprehend the global behavior of TEC. Neural Network (NN) models have been shown to accurately anticipate data patterns, including TEC. The capacity of neural networks to represent both linear and nonlinear relationships directly from the data being modeled is what makes them so powerful. The survey from literature reveals that, Levenberg-Marquardt algorithm is preferred and used mostly because of its speed and efficiency during learning process, and that ANN showed a good prediction of TEC compared to the IRI model. As a result, NNs are suitable for forecasting GPS TEC values at various locations if the model's input parameters are well specified.Item Chicken production, flock size, management systems, and challenges in the Dodoma region in Tanzania(Elsevier BV, 2021-06) Ngongolo, Kelvin; Chota, AndrewRaising chickens is an important activity in many resources constrained households in developing countries, as it is an important source of economic resilience as well as nutrition and food security. Despite its importance, the poultry industry faces many difficulties, including diseases due to low biosecurity and a lack of knowledge on proper management. A cross-sectional questionnaire survey was conducted to study the management practices that influence the performance of chickens in the households raising them in the Dodoma region of Tanzania. The results showed that 89% of respondents were vaccinating their chickens against diseases like Newcastle, fowlpox, infectious bursal disease and salmonellosis. However, many chicken farmers had incorrect information on the vaccination programs, including the frequency of vaccination and the timing of vaccinations, versus the provision of drugs for prophylactic purposes. The results showed that 29.5% of the farmers vaccinated weekly and 63.5% provided prophylactic drugs weekly. Furthermore, raising different types of chickens (OR = 1.45; p<0.01), frequency of vaccinations, (OR = 1.23; p<0.04), larger flocks of chickens (OR = 1.7; p<0.01), small number of chickens per drinker (OR = 1.64; p<0.05) and per feeder (OR = 2.4; p<0.05) were management factors associated with positive chicken performance in terms of growth rate, egg production and weight gain. It is recommended that the farmers are equipped with the necessary information on best management practices like vaccination regimes, prophylaxis timing and proper ratios of chickens per feeder and drinker.Item Core-envelope anisotropic star model admitting Karmarkar condition(Elsevier BV, 2024) Mathias, Amos V.; Sunzu, Jefta M.; Mkenyeleye, Jason M.We generate a neutral core-envelope stellar model with anisotropic fluid distribution which admits Karmarkar condition. The core and envelope layers are assumed to compose quark matter and neutron fluid consistent with linear and quadratic equations of state, respectively. The results obtained indicate that the present model conforms with physical and stability tests. In the present model we have generated radii and masses of astrophysical objects consistent with observations such as HerX-1, 4U 1538-52 and SAX J1808.4-3658. It is interesting to note that the study of multilayered stars in Karmarkar condition is missing in the stellar models generated in the past.Item The COVID-19 pandemic and its prolonged impacts on food prices, food consumption and diet quality in sub-Saharan Africa(Cold Spring Harbor Laboratory, 2022) Ismail, Abbas; Madzorera, Isabel; Apraku, Edward A.; Tinkasimile, Amani; Dasmane, Dielbeogo; Zabre, Pascal; Ourohire, Millogo; Assefa, Nega; Chukwu, Angela; Workneh, Firehiwot; Mapendo, Frank; Lankoande, Bruno; Hemler, Elena; Wang, Dongqing; Abubakari, Sulemana W.; Asante, Kwaku P.; Baernighausen, Till; Killewo, Japhet; Oduola, Ayoade; Sie, Ali; Soura, Abdramane; Vuai, Said; Smith, Emily; Berhane, Yemane; Fawzi, Wafaie W.Background Sub-Saharan Africa faces prolonged COVID-19 related impacts on economic activity, livelihoods, nutrition, and food security, with recovery slowed down by lagging vaccination progress. Objective This study investigated the economic impacts of COVID-19 on food prices, consumption and dietary quality in Burkina Faso, Ethiopia, Ghana, Nigeria, and Tanzania. Methods We conducted a repeated cross-sectional study and used a mobile platform to collect data. Data collected from round 1 (July-November, 2020) and round 2 (July-December, 2021) were considered. We assessed participants’ dietary intake of 20 food groups over the previous seven days. The study’s primary outcome was the Prime Diet Quality Score (PDQS), with higher scores indicating better dietary quality. We used linear regression and generalized estimating equations to assess factors associated with diet quality during COVID-19. Results Most of the respondents were male and the mean age (±SD) was 42.4 (±12.5) years. Mean PDQS (±SD) was low at 19.1 (±3.8) before COVID-19, 18.6(±3.4) in Round 1, and 19.4(±3.8) in Round 2. A majority of respondents (80%) reported higher than expected prices for all food groups during the pandemic. Secondary education or higher (estimate: 0.73, 95% CI: 0.32, 1.15), older age (estimate: 30-39 years: 0.77, 95% CI: 0.35, 1.19, or 40 years or older: 0.72, 95% CI: 0.30, 1.13), and medium wealth status (estimate: 0.48, 95% CI: 0.14, 0.81) were associated with higher PDQS. Farmers and casual laborers (estimate: -0.60, 95% CI: -1.11, - 0.09), lower crop production (estimate: -0.87, 95% CI: -1.28, -0.46) and not engaged in farming (estimate: -1.38, 95% CI: -1.74, -1.02) associated with lower PDQS. Conclusion Diet quality which had declined early in the pandemic had started to improve. However, consumption of healthy diets remained low, and food prices remained high. Efforts should continue to improve diet quality for sustained nutrition recovery through mitigation measures, including social protection.Item Spatial Distribution and Regulation of Fluoride in Groundwater of Singida Region in Tanzania(Elsevier BV, 2023) Andrew Toyi Banyikwaluoride (F- ) is a common geogenic source of groundwater pollution in central Tanzania, which includes the Singida region. Recommended levels of F- in drinking water set by the World Health Organization (WHO 2017) is 1.50 mgl-1. High F- exposure causes dental and skeletal fluorosis. The aim of this study was to evaluate the geochemistry, spatial distribution, and levels of F- in groundwater obtained from boreholes in seven districts of the Singida region. Results show that F- exists in the gradient and is more concentrated to the north than south and east than west of the region. Highest F- was found in Iramba district at 13.00 mgl-1. Singida rural and Mkalama districts located to the north of the region were found to have the highest percentage of samples with F- above 1.5 mgl-1 at 90.00 % and 81.80 % respectively. Manyoni and Itigi districts located to the south of the region were found to have lowest percentage of samples with F- above 1.5 mgl-1 at 11.10 % and 0.00 % respectively. Values for F- in Mkamala and Singida rural districts are max= 6.60 mgl-1, min = 0.06 mgl-1, mean and SD = 3.39±1.66 and max = 5.10mgl-1 , min = 0.64 mgl-1, mean and SD= 2.90±0.30 respectively. Positive correlation was found between pH, HCO3 - and F- . Negative correlation was found between F- and Ca2++Mg2+. Itigi district was found to have the lowest mean F- at 0.46 mgl-1 and highest ratios of Ca2+/F- and Mg2+/F- at 335.01 and 182.24 respectively. Mkalama district was found to have the highest mean F- at 3.39 mgl-1 and lowest ratios of Ca2+/F- and Mg2+/F- at 31.55 and 24.16 respectively. Conclusions; Ca2+ and Mg2+ play a major role in the regulation of F- . Groundwater in the north of the region requires F remediation before drinking.Item Influence of environmental factors on small mammal communities along an altitudinal gradient of Mount Rungwe in South Western Tanzania(Wiley, 2023) Richard Upendo; Magige Flora; Robert M. ByamunguThe study aimed to investigate the effects of environmental factors on the small mammal community in Mount Rungwe, Tanzania. To achieve this, three habitats low‐, mid‐mountainous forests at 1700–2000 and 2000–2400 m a.s.l., respectively, and bushland habitats at 2400–2800 m a.s.l. were sampled. Animal samples were collected during the wet and dry seasons in year 2020 and 2021 using live traps. A total of 12 species of small mammals were collected, comprising of nine rodents and three shrews. During the wet season, nine species were recorded, while 10 species were recorded during the dry season. Small mammals were more diverse and richer in the mid‐montane forests than in the low‐montane and bushland habitats. Furthermore, bushland habitats had significantly lower species composition than low‐ and mid‐mountain forests. In addition, low‐mountain forest exhibited high degrees of dominance and low level of evenness. The observed spatio‐temporal patterns of small mammals in terms of composition, richness, diversity, evenness and dominance are related to differences in habitat structure and seasonal variations. Based on the findings of this study, it is recommended to monitor forest communities to ensuring sustainable biodiversity conservation, with a particular focus on protecting habitats to increase small mammal diversity under changing environmental conditions.Item DFT studies of electronic properties, molecular descriptors and partition coefficients of tautomersof favipiravir: a potential drug for the treatment of COVID-19.(PakHeartJ, 2023) Monyjok, C. K.; Nhial, B. C.; Sagar, G. Y.; Babu, N. S.Computational quantum research was conducted for structural analysis of Favipiravir and its behaviour against COVID-19. Favipiravir customers were studied first of all and found to be regarded as ligands by four tautomeric structures. All calculations are performed in calculations of density functional theory (DFT). Conducted molecular docking simulations were allocated to similar protease and polymerase macromolecules in COVID-19. The utility of the descriptor values for global reactivity to predict the reactivity of the favipiravir tautomers has been determined by HOMO and LUMO energies. Compared to others, the FAtautomer exhibits a lower value,andone can assume that it is more likely that FAwill participate in electrophile reactions than other tautomers at any stage. The operation of amide-form favipiravir has a higher binding affinity with 6LU7 in the overall docking procedure compared to the other tautomer forms. The results showed that the four ligands would interact differently with each target. FKis the most stable,and FEis the most active macromolecular ligand. Ithas been found that ligands are not so strongly linked to the low values of connecting energies. The action of ligands is more favourableto protease than to polymeras a target. Qualitative ligand...target interaction representations have suggested various interaction environments with complex formations. Further research is also required to investigate Favipiravir's dominant activities against COVID-19.Item Ecological consequences of microplastic pollution in sub-Saharan Africa aquatic ecosystems: An implication to environmental health(Elsevier BV, 2024) Moto, Edward; Hossein, Miraji; Bakari, Ramadhani; Mateso, Alfred Said; Selemani, Juma Rajabu; Nkrumah, Salma; Ripanda, Asha; Rwiza, Mwemezi J.; Nyanza, Elias Charles; Machunda, Revocatus L.Microplastic pollution (MPs) emerged as a significant environmental concern due to its persistent nature. These MPs particles endure in waters, soils, and even the atmosphere, posing potential threats to the entire ecosystem. Aquatic organisms are at risk of ingesting MPs, leading to accumulation in tissues, ultimately affecting entire food chain. This study aims to provide an overview of sources of MPs, distribution, and potential environmental impacts. MPs have been documented in various substances such as bottled water, salts, seafood, and even the air. However, the full extent of the health consequences on human exposure remains uncertain. Therefore, it is imperative that we draw public attention to the presence of these pollutants in the environment. To mitigate adverse effects of MPs, reducing plastic consumption, implementing improved waste management practices, and advocating sustainable behaviors are essential for well-being of natural ecosystems and the health human populations.Item Optimal control of a threatened wildebeest-lion prey-predator system incorporating a constant prey refuge in the Serengeti ecosystem(Science Publishing Group, 2015) Sagamiko, Thadei Damas; Shaban, Nyimvua; Nahonyo, Cuthbert Leonard; Makinde, Oluwole DanielIn this paper a two species prey-predator model is developed in which prey is wildebeest and predator is lion and both are threatened by poaching, drought and diseases.The system is found in the Serengeti ecosystem.The model is constructed based on Holling type II functional response incorporating a constant prey refuge. We apply optimal control theory to investigate optimal strategies for controlling the threats in the system where anti-poaching patrols are used for controlling poaching, construction of dams for mitigating drought and vaccination for diseases control. The possible impact of using combinations of three controls either one at a time or two at a time on the threatened system plus a refuge factor is examined. All control strategies have shown significant increase in prey and predator populations . However, the best result is achieved by controlling all threats together. The effect of variation of prey refuge to the control of threats is studied and results indicate that increase of causes more prey individuals to be saved and reduces the number of predator individuals saved. This behaviour agrees with theoretical results obtained in co-existence equilibrium point.Item Spillover effects of medium- and large-scale farms on smallholder farmers in Tanzania: Evidence from the National Sample Census of Agriculture 2019/20(Elsevier BV, 2024) Abdulwahid, Nour; Bakari, Leguma; Hussein, Abdallah; Samwel K. Kawa; Lavoe, Francis; Mwisomba, Titus; Msuha, Basil; Wineman, AyalaTanzania has implemented a number of policies and initiatives to promote the growth of the agricultural sector. Among these are efforts geared toward fostering large-scale farm investments, which is partly premised on the notion that smallholder farmers will also benefit through improved access to factor markets and output markets, better prices, and knowledge transfers. Nevertheless, evidence on such spillover effects is far from clear. To fill this gap, we draw on the 2019/20 National Sample Census of Agriculture to estimate the spillover effects from large and medium-scale farms to smallholder farmers in Tanzania. Using logistic and linear regression models, we find evidence consistent with positive effects from medium-scale farms to smallholder farmers around adoption of improved technologies—particularly the use of improved seeds, organic fertilizer, irrigation, and mechanization—and crop yield. These relationships are more evident for maize farms. We also find evidence consistent with spillover effects from large-scale farms, specifically around the adoption of improved crop technologies and livestock vaccinations. These results add an argument in favor of policies that foster the coexistence of large-, medium-, and small-scale farms.Item Multivariate mixed-effects ordinal logistic regression models with difference-in-differences estimator of the impact of WORTH Yetu on household hunger and socioeconomic status among OVC caregivers in Tanzania(Public Library of Science (PLoS), 2024) Exavery, Amon; Kirigiti, Peter J.; Balan, Ramkumar T.; Charles, John; Moses KatbiBackground Although most of the livelihood programmes target women, those that involve women and men have been evaluated as though men and women were a single homogenous population, with a mere inclusion of gender as an explanatory variable. This study evaluated the impact of WORTH Yetu (an economic empowerment intervention to improve livelihood outcomes) on household hunger, and household socioeconomic status (SES) among caregivers (both women and men) of orphaned and vulnerable children (OVC) in Tanzania. The study hypothesized that women and men respond to livelihood interventions differently, hence a need for gender-disaggregated impact evaluation of such interventions. Methods This is a secondary analysis of longitudinal data, involving caregivers’ baseline (2016–2019) and follow-up (2019–2020) data from the USAID Kizazi Kipya project in 25 regions of Tanzania. Two dependent variables (ie, outcomes) were assessed; household hunger which was measured using the Household Hunger Scale (HHS), and Socioeconomic Status (SES) using the Principal Component Analysis (PCA). WORTH Yetu, a livelihood intervention implemented by the USAID Kizazi Kipya project was the main independent variable whose impact on the two outcomes was evaluated using multivariate analysis with a multilevel mixed-effects, ordinal logistic regression model with difference-in-differences (DiD) estimator for impact estimation. Results The analysis was based on 497,293 observations from 249,655 caregivers of OVC at baseline, and 247,638 of them at the follow-up survey. In both surveys, 70% were women and 30% were men. Their mean age was 49.3 (±14.5) years at baseline and 52.7 (±14.8) years at the follow-up survey. Caregivers’ membership in WORTH Yetu was 10.1% at the follow-up. After adjusting for important confounders there was a significant decline in the severity of household hunger by 46.4% among WORTH Yetu members at the follow-up compared to the situation at the baseline (adjusted Odds Ratio (aOR) = 0.536, 95% Confidence Interval (CI) [0.521, 0.553]). The decline was 45.7% among women (aOR = 0.543 [0.524, 0.563]) and 47.5% among men (aOR = 0.525 [0.497, 0.556]). Regarding SES, WORTH Yetu members were 15.9% more likely to be in higher wealth quintiles at the follow-up compared to the situation at the baseline (aOR = 1.159 [1.128, 1.190]). This impact was 20.8% among women (aOR = 1.208 [1.170, 1.247]) and 4.6% among men (aOR = 1.046 [0.995, 1.101]). Conclusion WORTH Yetu was associated with a significant reduction in household hunger, and a significant increase in household SES among OVC caregivers in Tanzania within an average follow-up period of 1.6 years. The estimated impacts differed significantly by gender, suggesting that women and men responded to the WORTH Yetu intervention differently. This implied that the design, delivery, and evaluation of such programmes should happen in a gender responsive manner, recognising that women and men are not the same with respect to the programmes.Item A finite difference study of radiative mixed convection MHD heat propagating Casson fluid past an accelerating porous plate including viscous dissipation and Joule heating effects(Elsevier BV, 2024) Reddy, B. Prabhakar; Matao, P.M.; Sunzu, J.M.A finite difference numerical simulation scrutiny is executed to evaluate the combined impacts of heat generation, buoyancy forces, viscous dissipation and Joule heating in unsteady hydro-magnetic mixed convective chemically reactive and radiative Casson fluid flowing along an exponentially accelerating permeable vertical plate engrossed in a porous media by considering ramp surface concentration and temperature. The dimensionless non-linear coupled PDEs describing the flow model are dealt numerically by adopting the competent implicit Crank-Nicolson finite difference procedure. The variance of velocity, temperature, and concentration distributions are exposed via graphical representations due to the dissimilarity of the flow restrained parameters. Computational outcomes of the skin-friction, Nusselt and the Sherwood numbers are portrayed in the tabular pattern. The final outcomes of the research exposed that the impacts of thermal radiation, viscous dissipation, and heat production parameters enlarges the temperature and velocity distributions. The fluid motion deflates for growing Casson parameter and magnetic field intensity. The rising chemical reaction parameter suppresses the concentration and velocity distributions. Very importantly it is distinguished that fluid momentum, temperature, and concentration are quicker in the instance of isothermal plate temperature than ramp wall temperature. This kind of research may find specific industrial and medical utilizations such as glass manufacturing, crude oil purification, lubrication, paper production, blood transport study in cardiovascular design, etc.Item Burden and Epidemiology of Snakebite Envenoming in Tanzania(Everant Journals, 2024) Kapyolo, Eliakimu Paul; Mabega, Ndakibae Gabriel; Mwingá, Gerald Phares; Mange, Fransis Basanda; Nagai, Honest Thomas; Mkama, Yusuph John; Jaffu, Derick Richard; Mnyagatwa, Petro Michael; Chilongani, Joseph Elieza; Lutambi, Angelina Mageni; Matemba, Lucas EliaimringiBackground: Snakebite envenoming (SBE) is a pressing public health issue in tropical countries. However, there is a paucity of data regarding the burden and epidemiology of SBE in Tanzania, undermining advocacy and the implementation of necessary prevention and control measures. Methods: From June to September 2022, both health facility-based and community-based survey was conducted to collect data of the snakebite incidents that occurred between 2017 and 2021 in five regions of Tanzania; Pwani, Manyara, Tabora, Katavi, and Ruvuma. Data were analysed using STATA and summarized by tables and narrative descriptions. Results: A total of 869 snakebite incidents were registered, resulting in 18 deaths. The estimated annual incidence, and mortality rates were 105.6, and 2.2 per 100,000 people, respectively. Pwani and Tabora regions exhibited a higher proportion of cases, accounting for 26% (226) and 23.4% (203) respectively. Males constituted the majority of cases, representing 52.5% (456), and individuals aged 10 to 59 years were most affected, accounting for approximately 85% of cases. The incidents commonly occurred during agricultural activities (31.5% or 219 cases) and while walking on rural roads (32% or 221 cases). Furthermore, snakebites were more prevalent during the dry season (34% or 295 cases) and the rainy season (25% or 218 cases). Factors such as time of day, season, circumstances/activities, occupation, age, and education level were found to be significantly associated with snakebite incidents. Conclusion: This study underscore the significant impact of SBE in Tanzania, affecting individuals of all age groups, particularly farmers. Urgent collaborative efforts are required to address and mitigate the consequences of SBE in the country.