2647 research outputs found
Sort by
Facile biosynthesis of Ag–ZnO nanocomposites using Launaea cornuta leaf extract and their antimicrobial activity
Get PDFThis research article was published by Discover Nano volume 18, 2023The quest to synthesize safe, non-hazardous Ag–ZnO nanoomposites (NCs) with improved physical and chemical properties has necessitated green synthesis approaches. In this research, Launaea cornuta leaf extract was proposed for the green synthesis of Ag–ZnO NCs, wherein the leaf extract was used as a reducing and capping agent. The antibacterial activity of the prepared nanoomposites was investigated against Escherichia coli and Staphylococcus aureus through the disc diffusion method. The influence of the synthesis temperature, pH, and precursor concentration on the synthesis of the Ag–ZnO NCs and antimicrobial efficacy were investigated. The nanoparticles were characterized by ATR-FTIR, XRD, UV–Vis, FESEM, and TEM. The FTIR results indicated the presence of secondary metabolites in Launaea cornuta which assisted the green synthesis of the nanoparticles. The XRD results confirmed the successful synthesis of crystalline Ag–ZnO NCs with an average particle size of 21.51 nm. The SEM and TEM images indicated the synthesized nanoparticles to be spherical in shape. The optimum synthesis conditions for Ag–ZnO NCs were at 70 °C, pH of 7, and 8% silver. Antibacterial activity results show Ag–ZnO NCs to have higher microbial inhibition on E. coli than on S. aureus with the zones of inhibition of 21 ± 1.08 and 19.67 ± 0.47 mm, respectively. Therefore, the results suggest that Launaea cornuta leaf extract can be used for the synthesis of Ag–ZnO NCs
Reconstructing historical distribution of large mammals and their habitat to inform rewilding and restoration in central Tanzania
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in Biodiversity and Ecosystem Management of the Nelson Mandela African Institution of Science and TechnologyIn the anthropogenic landscapes where historically wildlife existed, there can be a potential for
rewilding to reverse extinction. However, there is limited literature providing approaches to
achieving successful rewilding. The current study aimed at providing empirical based
methodological procedures for the successful rewilding of large mammals at the University of
Dodoma (UDOM) and nearby degraded landscapes by assessing past and current vegetation
and wild mammals’ occurrence and soil fertility. The past occurrence of mega-herbivores and
their habitat was assessed using literature survey, past vegetation maps and key-informant
interviews. The EBSCOhost-database and Google Scholar search-engine were used for
literature searching. A field survey was conducted at UDOM, one of the remaining habitat
patches in central areas of Dodoma, Tanzania to examine present plant diversity, soil nutrients
and seedbank status. The results indicated that historically, the study area was Savanna woodland but later anthropogenic activities had resulted in Land-Use Land-Cover Changes
(LULCC) that led to wild animals’ extirpation leaving remnants in the surrounding protected
areas. While the key informant interviews verified the local loss of mega-herbivores, data
collected at UDOM in 2022 indicated vegetation transformation to Dichrostachys cinerea dominated bushland. The study further revealed moderate soil fertility with relatively high
seedbank. These results indicated that the study area occupied specular wild-mammal
populations that were later extirpated leaving the area transformed into bushland. For rewilding
programmes, among other things, the information generated from this study is essential and
should be used to guide the long-term success of re-introduction at UDOM and its adjacent
areas with/without modification
Predation efficacy of anopheles funfests larvae by Aquatic predators in rural South Eastern –Tanzania
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of
Master of Science in Public Health Research of the Nelson Mandela African Institution
of Science and TechnologyThe study aimed to examine the impact of 3 common predator on Anopheles funestus larvae.
Specifically, (a) The impact of predator on larval and adult density (b) The impact of aquatic
predation on fitness traits of Anopheles funestus mosquitoes (wing size, larval and adult
survivals) in the semi-field system. Three selected predator families (Aeshnidae,
Coenagriondae and Notonectidae) and Anopheles funestus group larvae were collected from
the natural aquatic habitats in rural south eastern Tanzania and transferred to the semi-field
system (Mosquito city) at Ifakara Health Institute. Anopheles funestus larvae were exposed to
artificial habitats with predators. The number of surviving Anopheles funestus larvae were
counted after 24 hours. Remaining larvae were monitored until all they are consumed or
developed into pupae stage. An emerged trap was placed at the top of artificial habitats to
capture an emerging mosquito. Emerged mosquitoes were provided 10% glucose solution-
soakes cotton wool and their 24 hours mortality were recorded. Wings of died female
mosquitoes were measured and used as a proxy for their body sizes. All predators were
significantly reduced the Anopheles funestus density, affect the survival and wing sizes of
emerged mosquitoes. Coenagrionidae were most efficient predators followed by Notonectidae
while Aeshinidae were least efficient predators on Anopheles funestus larvae. The current study
suggest that these aquatic predators may play an important role as complementary tool in
reducing Anopheles funestus larval population and hence contribute to the reduction of the
malaria vectors in Southern eastern Tanzania. Further investigations should be done in a real
natural aquatic habita
Dietary Practices, Nutritional status, Risk of exposure to aflatoxins and Pesticide among adolescents in Boarding - high schools in Kilimanjaro, Tanzania
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of
Doctor of Philosophy in Life Sciences of the Nelson Mandela Africa Institution of Science
and TechnologySchool feeding in low income countries relies mainly on cereals and legumes. Cereals are
low in nutrients and its overdependence can lead to poor nutrient intake. Cereals and legumes
are susceptible to aflatoxins contamination, causing both acute and chronic toxicity in human.
The use of pesticide has been one of the measures to control aflatoxins. Inappropriate
pesticides use may result to unacceptable residues in grains. A cross sectional study was
conducted to assess dietary practices, nutrition status, the risks of exposure to aflatoxins and
pesticide among adolescents through consumption of school meals in Kilimanjaro region.
Food frequency questionnaires and 24 hours’ dietary recalls were used to collect food
consumption information. Nutrition status was assessed using anthropometry and test of
hemoglobin levels. World Health Organization. Arthro plus and Nutri survey software were
used to analyze anthropometry and dietary data respectively. Aflatoxin and pesticide residues
were analyzed using High Performance Liquid chromatography (HPLC), and Gas
Chromatography Mass spectrometer (GC-MS), respectively. Results shows that, maize based
food and beans were consumed on daily basis with low intake of animal sources, vegetables
and fruits. Mean intake of Vitamin C, iron, calcium and zinc were below the Recommended
Daily Allowance (RDA). The average carbohydrates, fats and proteins intake were slightly
higher than RDA for adolescents. Overall 23.1% of the adolescents were anemic, 25%
overweight and 6.1% obese. Total aflatoxins contamination ranged from 0.20 - 438.53 μg/kg
and aflatoxin B1 (AFB1) ranged from 0.44 μg/kg to 35.89 μg/kg. The highest exposure to
total aflatoxins ranged from 0.70-973.45 ng/kg/bw/day and AFB1 ranged from 0.05-81.06
ng/kg/bw/day. Pesticide residues in all samples were below the detection limits, implying no
risk to pesticide exposure among the studied individuals. Inadequate nutrients intake and the
pronounced risk of exposure to aflatoxins could have been contributed by a monotonous
cereal and legume based diet in boarding schools. The no detects of pesticide residues might
have been contributed by degradation of pesticide due to the prolonged storage, milling
process, and uses of silos for storage. The relevant ministries should consider food
diversification and routine risk assessments of the susceptible crops throughout the value
chain as a long-term intervention plan
AI for anglophone africa: unlocking its adoption for responsible solutions in academia-private sector
Get PDFThis research article was published by frontiers,2023In recent years, AI technologies have become indispensable in social and industrial
development, yielding revolutionary results in improving labor efficiency, lowering
labor costs, optimizing human resource structure, and creating new job demands.
To reap the full benefits of responsible AI solutions in Africa, it is critical to
investigate existing challenges and propose strategies, policies, and frameworks
for overcoming and eliminating them. As a result, this study investigated the
challenges of adopting responsible AI solutions in the Academia-Private sectors
for Anglophone Africa through literature reviews, expert interviews, and then
proposes solutions and framework for the sustainable and successful adoption
of responsible AI
A Machine Learning Model for detecting Covid-19 Misinformation in Swahili Language
Get PDFThis research article was published by Engineering, Technology & Applied Science Research,Vol. 13 No,2023.The recorded cases of corona virus (COVID-19) pandemic disease are millions and its mortality rate was maximized during the period from April 2020 to January 2022. Misinformation arose regarding this threat, which spread through social media platforms, and especially Twitter, often spreading confusion, social turmoil, and panic to the public. To identify such misinformation, a machine learning model is needed to detect whether the given information is true (true information) or not (misinformation). The aim of this paper is to present a machine-learning model for detecting COVID-19 misinformation in the Swahili language in tweets. The five machine learning algorithms that were trained for detecting Swahili language misinformation related to COVID-19 are Logistic Regression (LR), Support Vector Machine (SVM), Bagging Ensemble (BE), Multinomial Naïve Bayes (MNB), and Random Forest (RF). The study used the qualitative research method because non-numerical data, i.e. text, were used. Python programming language was used for data analysis due to its powerful libraries such as pandas and numpy. Four metrics were used to evaluate the model performance. The results revealed that SVM achieved the highest accuracy of 83.67% followed by LR with 82.47%. MNB achieved the best precision of 92.00% and in terms of recall and F1-score, RF, and SVM achieved the best results with 84.82% and 81.45%, respectively. This study will enable the public to easily identify Swahili language misinformation related to COVID-19 that is circulated on Twitter social media platform
The Status and Risk Factors of Brucellosis in Smallholder Dairy Cattle in Selected Regions of Tanzania
Get PDFThis research article was published by MPDI, 2023Bovine brucellosis is a bacterial zoonoses caused by Brucella abortus. We conducted a cross-sectional study to determine brucellosis seroprevalence and risk factors among smallholder dairy cattle across six regions in Tanzania. We sampled 2048 dairy cattle on 1374 farms between July 2019 and October 2020. Sera were tested for the presence of anti-Brucella antibodies using a competitive enzyme-linked immunosorbent assay. Seroprevalence was calculated at different administrative scales, and spatial tests were used to detect disease hotspots. A generalized mixed-effects regression model was built to explore the relationships among Brucella serostatus, animals, and farm management factors. Seroprevalence was 2.39% (49/2048 cattle, 95% CI 1.7–3.1) across the study area and the Njombe Region represented the highest percentage with 15.5% (95% CI 11.0–22.0). Moreover, hotspots were detected in the Njombe and Kilimanjaro Regions. Mixed-effects models showed that having goats (OR 3.02, 95% C 1.22–7.46) and abortion history (OR 4.91, 95% CI 1.43–16.9) were significant risk factors for brucellosis. Education of dairy farmers regarding the clinical signs, transmission routes, and control measures for brucellosis is advised. A One Health approach is required to study the role of small ruminants in cattle brucellosis and the status of brucellosis in dairy farmers in the Njombe and Kilimanjaro Regions
Towards an Artificial Intelligence Readiness Index for Africa
Get PDFThis research article was published by Springer Nature in 2023The applications and benefits of Artificial Intelligence (AI) for socio-economic development are immense. AI is projected to contribute approximately USD 15.7 trillion to the global Gross Domestic Product (GDP) by 2030. However, countries need to be prepared to harness such benefits. Hence, assessing the AI readiness of a country is paramount. Africa is currently the only continent without an AI readiness index tailored to its needs. It relies on the existing global indices, which may not accurately measure the progress attained by individual African countries because of the different levels of development and unique context. This paper proposes an AI readiness index for Africa. It starts by exploring what the AI readiness index needs of Africa are, examines the extent to which existing AI readiness indices meet the needs, and then looks at indicators that should constitute the AI readiness index for Africa.
The study employed a systematic literature review that aimed to explore the AI readiness needs for Africa and the extent existing indices meet these. The review focused on papers published on the AI readiness index between January 2018 to August 2022. The search strategy retrieved 301 papers, of which seven papers were selected for a detailed analysis. The study revealed that the existing indices partially meet AI readiness needs for Africa. The study also found that AI readiness index dimensions pertinent to Africa’s requirements are: Vision, Governance and Ethics, Digital Capacity, Size of the Technology Sector, Research and Development, Education, Infrastructure, Data Availability, general level of employment, employment in Data Science and AI roles, and Gross Domestic Product-Per Capita Purchasing Power Parity. This study contributes to the knowledge of AI readiness for Africa and globally. The results of this study will benefit governments, researchers, and practitioners of AI and its applications
Provision of low‐aflatoxin local complementary porridgeflour reduced urinary aflatoxin biomarker in childrenaged 6–18 months in rural Tanzania
No full textThis research article was published by Wiley Online Library in 2023Aflatoxins are toxic secondary metabolites of fungi that colonize staple food crops,
such as maize and groundnut, frequently used in complementary feeding. In
preparation for a large trial, this pilot study examined if provision of a low‐aflatoxin
infant porridge flour made from local maize and groundnuts reduced the prevalence
of a urinary aflatoxin biomarker in infants. Thirty‐six infants aged 6–18 months were
included from four villages in Kongwa District, Tanzania. The study was conducted
over 12 days with a three‐day baseline period and a 10 days where low‐AF porridge
flour was provided. Porridge intake of infants was assessed using quantitative 24‐h
recalls by mothers. Household food ingredients used in infant porridge preparation
and urine samples were collected on Days 1–3 (baseline) and 10–12 (follow‐up).
Aflatoxins were measured in household foods, and AFM1 was measured in urine. At
baseline and follow‐up, 78% and 97%, respectively, of the infants consumed
porridge in the previous 24 h, with a median volume of 220 mL (interquartile
range [IQR]: 201, 318) and 460 mL (IQR: 430, 563), respectively (p < 0.001).
All 47 samples of homemade flour/ingredients were contaminated with AFs
(0.3–723 ng/g). The overall prevalence of individuals with detectable urinary
AFM1 was reduced by 81%, from 15/36 (42%) at baseline to 3/36 (8%) at follow‐
up (p = 0.003). Provision of low‐aflatoxin porridge flour was acceptable to caregivers
and their infants and successfully reduced the prevalence of detectable urinary
AFM1 in infants, thus, confirming its potential to be tested in future large‐scale
health outcomes trial
Effects of different supplementary cementitious materials on durability and mechanical properties of cement composite – Comprehensive review
Get PDFThis research articles was published in Journals Heliyon Volume 9, ISSUE 7, 2023Ordinary Portland cement is the highest produced cement type in the world, however its pro-
duction is high energy consumption means expensive, huge natural resource consumptive, and
creating high environmental pollution. Hence many researchers studied to reduce the effect of
ordinary Portland cement by substituting artificial and natural supplementary cementitious
materials (SCMs) commonly in a concrete/mortar mixture. However, the comprehensive effect of
different SCMs on various properties of cement composite materials are not well known. So the
present study sought to review the effect of different natural and artificial SCMs on the durability
and mechanical properties of cement composites, especially due to their doses, types, chemical
composition, and physical properties. Hence the review shows that many SCMs used by literatures
from different places satisfy ASTM replacement standard based on their chemical compositions.
Also, the review indicated as adding 5–20% of different SCMs positively affect mechanical
properties, durability, and microstructures of the cement composite materials, specifically as most
researchers found isolately adding of 15% SCMs such as bentonite, kaolin, and biomass, 20%
addition of volcanic ash and 10% employment of fly ash, silica fume, and zeolite to the cement
composites achieves the most optimum compressive and split tensile strength. These observations
reveal that most natural pozzolana can more replace cement to give optimum strength, hence can
more reduce energy consumption, production cost, and environmental pollution comes due to
cement production. Furthermore, most researchers found employing different SCMs generally
improves durability, however there is a limited study on the effect of silica fume on water ab-
sorption and acidic attack resistance of cementitious materials. Therefore, it is recommended that
future research should also focus more to know the effect of silica fume on the durability of
cement composites