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Seasons and bee foraging plant species strongly influence honey antimicrobial activity
Get PDFThis research article was published in Journal of Agriculture and Food Research, Volume 12, 2023.Honey has been used in human medicine since ancient times due to its antimicrobial properties. However, honey antimicrobial potential varies due to floral sources, geographical origins, and seasonality. The current study assessed the antimicrobial activity of honey and honeybees’ preferred plants namely, Acacia mellifera, Ocimum basilicum, Hoslundia opposita, Combretum schumannii, Grewia bicolor, Terminalia brownii, Cordia monoica from Same district in Northern Tanzania, during the short and long rain seasons of 2021/2022. The agar well diffusion method was employed for the antimicrobial assay, and the antimicrobial activity was evaluated by measuring inhibition zones. Significant differences were observed in antimicrobial activities among honey of different seasons (F = 28.5, p = <0.001) and plant extracts (F = 15.9, p < 0.001). Honey A and D that were harvested at the end of the short rain season were found with higher antimicrobial activities (10–19 mm inhibition) than that harvested at the end of the long rain season (10–15 mm inhibition), and the most susceptible microorganisms were Escherichia coli and Staphylococcus aureus. For the tested plant extracts, T. brownii, C. schumannii, and H. opposita showed higher antimicrobial activities (11.3–19 mm inhibition) against pathogenic microorganisms than other tested plants. There was a strong positive correlation in antimicrobial activities (r = 0.836, p = 0.078, r = 0.756, p = 0.139, and r = 0.732 p = 0.159) between honey harvested at the end of the short rain season with some plant extracts from plants blooming during the same season. The study highlighted the variation in antimicrobial activities among honey harvested in different rain seasons and that there is antimicrobial relation between honey and plants that are foraged by honeybees. Thus, the antimicrobial ability of the honey depends much on the plant species foraged by honeybees
Effect of groundwater residence time on geogenic fluoride release into groundwater in the Mt. Meru slope area, Tanzania, the Great Rift Valley, East Africa
Get PDFThis research articles was published Journal of Contaminant Hydrology Volume 253,2023People living in the Great Rift Valley in East Africa suffer from fluorosis resulting from their consumption of groundwater. This paper shows that geogenic fluoride contamination in a natural water system has changed in the last two decades in the Mt. Meru slope area of northern Tanzania based on water quality, dating of the residence time, and stable isotopes of groundwater. The results demonstrate that 1) the average recharge altitude of groundwater with a high geogenic fluoride concentration is estimated to range from 1900 m to 3000 m on the southern slope of Mt. Meru, and the fluoride concentration tends to increase with an increase in the recharge altitude, 2) the fluoride concentration increases with increasing groundwater residence time for groundwater with a residence time of 20 years or longer, suggesting that water-rock interaction processes (weathering, dissolution, and ion exchange), which depend on the contact time between the volcanic aquifer and groundwater, have predominated for approximately 20 years or longer, and 3) the mixing of aerobic young water and old groundwater has been active for approximately 20 years, and the fluoride concentration is increasing in some shallower well waters. The mixing of fluoride-contaminated groundwater with aerobic water infiltrating the aquifer through pumping groundwater in the last two decades may increase the spread of groundwater contaminated with fluoride due to increased water demand caused by rapid population growth, and urbanization, industrial growth, and the expansion of irrigated agriculture
Nutrient intake and dietary adequacy among infants in Kongwa District, Tanzania: A sub-study of the Mycotoxin Mitigation Trial
Get PDFThis research article was published in the Research Square in 2023Background: Early exposure to aflatoxin, a common toxin in global food systems, has been associated with child growth faltering. The Mycotoxin Mitigation Trial was a community-based cluster-randomized trial designed to assess the effect of dietary aflatoxin on stunting. The study provided low aflatoxin pre- blended porridge flour and groundnuts flour to the Intervention arm, while the same porridge recipe from home ingredients was promoted through education to the Standard of Care (SOC) arm. The objective was to isolate the effect of aflatoxin consumption while keeping dietary intake otherwise the same between the two arms.
Methods: To assess dietary intake, we performed a cross-sectional study on trial participants to evaluate and compare nutrient intake and adequacy of protein, energy, lipid, iron, zinc, calcium, and vitamin A between the randomized arms of the study. Twenty paired clusters (10 per trial arm) were selected, with up to 15 households per cluster randomly selected for a structured, multi-pass 24-h recall in three different rounds of data collection at 12 months of age.
Results: A total of 282 children participated. Nutrient intake was estimated from mixed models to account for clusters. The mean daily intakes of energy and lipid were 505 kcal and 13 mg respectively in the intervention and SOC while intervention children consumed slightly more proteins (13.7 g v 12.3 g, p= 0.02). There were no differences between the arms regarding the consumption of iron, zinc, calcium, or vitamin A. Generally, Iron and zinc consumption was very low.
Conclusion: At the midpoint of the trial intervention only protein consumption differed between arms. Both arms met RNI for energy, protein, and vitamin A but not for other nutrients assess
Applicability of bio-adsorbents synthesized from maize/corn plant residues for heavy metals removal from aquatic environments: an insight review
Get PDFThis research article was published in EQA-International Journal of Environmental Quality, Volume 56, 2023The underutilization of agricultural waste products in recent years has resulted in environmental issues owing to improper disposal. As a result, heavy metals removal from aqueous systems utilizing sorbent materials produced from agricultural wastes has received a lot of attention. The current study provides an insightful review of the use of bio-adsorbents synthesized from maize/corn residues to decontaminate various toxicants from wastewater. Although bio-adsorbents made from maize/corn residues have shown to be efficient in the sequestration of heavy metals from wastewater, no study has looked at hybrid bio-adsorbents made from various parts of the maize/corn plant. Moreover, all studies practically investigate the sorption processes using the one-factor design technique, which exceedingly consumes time and is expensive for a significant number of biosorption/adsorption factors. Besides, the majority of the studies used bio-adsorbents produced from maize/corn biomass to remove heavy metals from single sorption systems. Furthermore, very few studies have focussed on heavy metals desorption from the exhausted maize/corn bio-adsorbents following the adsorption process to recycle the spent bio-adsorbents for future usage, which would be more cost-effective. Based on the gaps revealed in this review, it is recommended that further investigations on the usefulness of bio-adsorbents derived from maize/corn biomass in cleansing different water toxicants should be carried out
A Blockchain-based Conceptual Model to Address Educational Certificate Verification Challenges in Tanzania
Get PDFThis research article was published in the Engineering, Technology & Applied Science Research Vol. 13, No. 5, 2023The proliferation of counterfeit educational certificates is an ongoing issue around the world, including
Tanzania. The effect of this malpractice is detrimental to the credibility of education. Traditional strategies
to prevent fake certificates are abortive, calling for a more sophisticated approach. Blockchain technology
has recently emerged as an ideal solution to this problem due to its inherent attributes that ensure
disintermediation, immutability, tamper proof, anonymity, transparency, consensus, security, and trust.
However, most existing blockchain-based solutions lack crucial functionalities that are pertinent to the
Tanzanian education system. This study unveiled the challenges faced by the current verification system in
Tanzania and proposed a blockchain-based conceptual model to address them. The proposed model is
based on blockchain, smart contracts, and the Interplanetary File System (IPFS). Quantitative and
qualitative methods were used to investigate certification problems in Tanzania and modeling techniques
were used to construct the conceptual model. The findings showed that the main challenges of the current
verification system emanate from manual procedures, unverifiable credentials, susceptibility of centralized
storage systems, disintegrated verification systems, revocation problems, difficulties in communication,
and high dependency on the issuers. These challenges undermine certificate verification, impose a
significant setback in the fight against forgeries, and create loopholes for forgeries to persist. It was
conceptually demonstrated that these issues can be resolved through the proposed blockchain-based
solution
Farmers’ Knowledge on Whitefly Populousness among Tomato Insect Pests and Their Management Options in Tomato in Tanzania
Get PDFThis research article was published by MDPI in 2023Whitefly is a populous insect pest among tomato insect pests, causing significant crop loss through direct and indirect attacks. The current study aimed to assess the knowledge of tomato farmers on the populousness of whiteflies compared to other tomato insect pests and explore the management options available in their farming context in three tomato-growing regions, Arusha, Morogoro, and Iringa, in Tanzania. The study used a questionnaire to collect the data with backup information obtained through key informants’ interviews and focus group discussions. The study findings indicated whitefly to be populous among tomato insect pests. However, tomato farmers showed varying knowledge of whitefly aspects, including differing control options for the pest. Such findings indicated a knowledge gap between farmers’ understandings of the pest and their practices in fighting it compared to the standard and required practices in controlling the pest
Fabrication of liposome-chitosan-zno nanohybrid integrated with Carissa Spinarum extract for antibacterial application
Get PDFA Thesis Submitted in Fulfilment of the Requirements for the Degree of Doctor of
Philosophy in Life Sciences of the Nelson Mandela African Institution of Science and
TechnologyInnovative biomaterials provide a stimulating and adaptable platform for the implementation
of new and more effective methods to prevent bacterial infection. Built on biomimetic-
inorganic hybrid material, Dual Nanohybrid Delivery System (DN-DS) has advantageous
properties for biomedical applications, such as the delivery of herbal formulations for the
treatment of bacterial infections.
Using microwave assisted extraction (MAE), the polyphenols of Carissa spinarum were
extracted. The Dual Nanohybrid Delivery System (LipCsP-ZnONPs)-CT was formed by
combining LipCsP-Chitosan and ZnO-Chitosan, which were both generated using different
methods of co-precipitation and ion gelation, respectively. A Zetasizer was used to characterize
the nanosystems' size, zeta potential, and polydispersity index (PDI). A UV-visible
spectrophotometer was utilized for the optical study, and a scanning electron microscope was
employed to investigate at the surface morphology. The interaction of coated chitosan with
liposomes and ZnONPs was evaluated using Fourier Transformation Infrared (FTIR)
spectroscopy. Different kinetic models were fitted to the results of the encapsulation and release
profiles of polyphenols in the liposome nanosystems to determine the mechanism of release.
Antibacterial activity of the nanoformulations was assessed by an agar diffusion assayand the
micro plate blue assay (MABA).
The Zeta potential of LipCsP changed from -45.3 ± 0.78 to +34.43 ±1.36 due to chitosan
coatings. Polyphenol-encapsulation efficiency was higher in LipCsP-Chitosan (81 ± 2.5%) than
in LipCsP (66.11 ± 1.11%). Conversely, the size of LipCsP (176.17 ± 1.05 nm) increasedto
365.2 ± 0.70 nm. FTIR analysis revealed the interaction of the liposome with chitosan due to
the disappearance of N-H primary amine. Interaction between chitosan and zinc oxide was
revealed by the formation of new absorption peaks at 670 cm-1 and 465 cm-1 as observed in the
FTIR analysis. (LipCsP-ZnONPs)-CT presented high bioaccessibility of polyphenols in the
simulated gastric phase (82.14 ± 0.80%) than in simulated intestinal phase (71.60 ± 0.86%), a
stable system for sustained release of polyphenols, and prominent antibacterial activity.
(LipCsP-ZnONPs)-CT exhibited a relative inhibition zone diameter (RIZD) of 89.60 ± 1.32,
significant high viability reduction (P˂0.05) against Klebsiella pneumoniae as compared to
LipCsP-Chitosan and ZnO-chitosan. The nanohybrid systems (LipCsP-Chitosan and ZnO-
chitosan) exhibited synergistic effect against Klebsiella pneumoniae. This study successfully
demonstrated the utility of the nanohybrid as a potential antibacterial agent against K.pneumoniae, therefore, the fabricated dual nano delivery system is an efficacy material for
treatment of pneumococcal infections
Process evaluation of Community-Based continuous mass dog vaccination delivery Strategies in the Mara region of Tanzania
Get PDFA Thesis Submitted in Fulfilment of the Requirements for the Degree of Doctor of
Philosophy in Life Sciences of the Nelson Mandela African Institution of Science and
TechnologyRabies can be eliminated if coverage of domestic dog vaccination is sustained above 40% all
year-round for five-seven consecutive years. Current approaches usually fail to achieve this
required vaccination coverage and an alternative, a community-based continuous mass dog
vaccination (CBC-MDV) approach, was designed and piloted in the Mara region of Tanzania.
This thesis used mixed, qualitative, quantitative and participatory methods to evaluate the
development and delivery of the CBC-MDV approach over two years to generate evidence to
inform the optimization of the design prior to its evaluation in a full-scale randomized control
trial. Specifically, it investigated the feasibility and fidelity of delivery and potential
effectiveness of the CBC-MDV strategies, drivers of innovations in the implementation
process, whether and how community engagement can be used to address barriers to
participation in mass dog vaccination (MDV) campaigns and what factors will determine the
normalization of CBC-MDV as the standard approach for delivering MDV in Tanzania.
Qualitative data were analyzed using thematic analysis, both inductive and deductive.
Quantitative data on delivery of CBC-MDV were analyzed descriptively. Regression analysis
was used to identify population-related factors that have implications for participation in MDV.
Two-proportion Z-tests and Mann-Whitney U test were used to assess whether the community
engagement strategies were effective and can address barriers to participation in MDV
campaigns. The findings showed that the development process of CBC-MDV was iterative and
involved cross-sectoral participation but without the direct involvement of communities. In
relation to feasibility, fidelity and potential effectiveness, CBC-MDV was delivered with 69%
fidelity and performed better in terms of sustaining high vaccination coverage compared to the
centralized approach. Design-, implementer- and context-related factors influenced delivery
and effectiveness of the CBC-MDV strategies. We found that the community engagement
activities positively influenced factors that underpin participation in MDV campaigns. In
relation to integrating and sustaining the new approach in practice, CBC-MDV was well
understood, accepted, operationalized with relative ease and positively appraised compared to
the centralized approach. We conclude that it was feasible to deliver CBC-MDV in the context
of Tanzania, it can be sustained in practice, and barriers to participation in mass dog vaccination
can be addressed through community engagement processes. However, community
participation in the design, delivery and evaluation of CBC-MDV is needed to foster ownership
and sustainability of the intervention
Sensitivity analysis and parameters estimation for the transmission of lymphatic filariasis
Get PDFThis Research Article was published by the Heliyon, 2023Lymphatic filariasis is a neglected tropical disease which poses public health concern and socio-
economic challenges in developing and low-income countries. In this paper, we formulate a
deterministic mathematical model for transmission dynamics of lymphatic filariasis to generate
data by white noise and use least square method to estimate parameter values. The validity of
estimated parameter values is tested by Gaussian distribution method. The residuals of model
outputs are normally distributed and hence can be used to study the dynamics of Lymphatic
filariasis. After deriving the basic reproduction number, 0 by the next generation matrix
approach, the Partial Rank Correlation Coefficient is employed to explore which parameters
significantly affect and most influential to the model outputs. The analysis for equilibrium states
shows that the Lymphatic free equilibrium is globally asymptotically stable when the basic
reproduction number is less a unity and endemic equilibrium is globally asymptotically stable
when 0 ≥ 1. The findings reveal that rate of human infection, recruitment rate of mosquitoes
increase the average new infections for Lymphatic filariasis. Moreover, asymptomatic individual contribute significantly in the transmission of Lymphatic filariasi
A quantity-quality tradeoff: Water quality and poverty assessment of drinking water sources in southern Tanzania
No full textA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree Masters in Environmental Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyRegardless of being essential for human survival, access to potable water is still a problem in many
rural African communities with increasing exposure to waterborne illnesses. This study aimed at
establishing accessible quality water sources in 5 drinking water sources in rural southern
Tanzania. The water quality index (WQI) and water poverty index (WPI) were utilized to grade
and measure the water quality and water stress respectively. The 26 households participated in a
socioeconomic survey to gauge the water accessibility in relation to four WPI factors viz.,
preference, accessibility (distance), quality, and seasonal availability. Results from the WPI
computed data revealed that all the investigated water sources possessed poor quality with 222.5
and 112 for surface water and shallow wells (>50 excellent, <300 unsuitable). The WPI scores for
shallow wells were safer than surface water at 45.7 as contrasted to 33.8 for surface water (0-
poorest levels, 100-best levels). This study concluded that, in this area, shallow wells have more
secure water in terms of quality and accessibility. Health data from Milola ward showed high
occurrences of water borne diseases. This study recommends urgent water treatment intervention
by the responsible stakeholders to avail clean, reliable, and accessible drinking water for vulnerable
communities