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Development of maize-based composite flour enriched with mushroom for complementary feeding
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of
Master’s in Life Sciences of the Nelson Mandela African Institution of Science and
TechnologyComplementary foods based on habitual cereals such as maize have been linked with the
promotion of under-nutrition in young children. This study aimed at improving the nutritional
value of maize flour commonly used as a bulk ingredient in complementary foods using oyster
mushroom (Pleurotus ostreatus). Drying methods for fresh mushroom was done by using oven,
sun and solar drier. Flour made of well cleaned and solar-dried oyster mushroom was blended
with maize flour at 0% (control), 30%, 40% and 50%. Solar drying was the best method in
terms of nutrient retention of oyster mushroom, product hygiene and safety. Flour blend of
30%, 40% and 50% oyster mushroom improved the protein content from 8.63% to 18.20%,
8.63% to 20.37% and 8.63% to 22.75%, respectively. The increase in ash and fiber content
ranged between 82.52% to 84.16% and 50.69% to 58.35%, respectively. Mineral content of
formulated flour blends was improved from 62.89% to 64.72% (iron); 7.63% to 22.69 % (zinc);
77.48% to 78.02% (calcium) and 67.55% to 67.64% (potassium). The flour blend of 50%
oyster mushroom was the best as it was rich in nutrients compared to flour blends comprised
of 30 and 40% oyster mushroom. Sensory scores of porridge prepared from the three
formulated flour blends indicated good acceptance. This study recommends blending oyster
mushroom with maize flour to improve their nutritional content of formulated flour blend for
young children who rely on maize porridge as their complementary food
Development of model for early identification of tomato plant damages caused by TUTA ABSOLUTA
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Master’s in Information and Communication Science and Engineering of the Nelson
Mandela African Institution of Science and TechnologyPlant pests and diseases challenge the agricultural sector. A high-yielding crop, such as tomato
which has the potential to increase income of smallholder farmers, its production is threatened
by invasive pest called Tuta absoluta. Despite many efforts made by farmers in its
management, has continued to be a great constraint, hence calling for scholars to devise
approaches of identifying and combating it before causing great losses to farmers. This study
introduces, a deep learning based approach for the identification of the pest at early stages of
tomato growth through classification of tomato leaf images. In this study, the Convolutional
Neural Network architectures (VGG16, VGG19 and ResNet50) were trained on tomato
images dataset captured from the field containing healthy and infested tomato leaves.
Evaluation of performance for each classifier was done by considering accuracy of classifying
the tomato leaf into correct category. Experimental results showed that VGG16 attained the
highest accuracy of 91.9% in classifying tomato plant leaves into correct categories. This
model can be deployed and used to establish tool for early detection of Tuta absoluta pes
An investigation of adequacy of the current micronutrient fortification in the mandatory fortified food vehicles in Tanzania
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Master’s in Life Sciences of the Nelson Mandela African Institution of Science and
TechnologyMicronutrient fortification of cooking oil, wheat and maize flours is mandatory in Tanzania
since 2011. Up-to-date information regarding the compliance of micronutrient fortification is
limited in the country. This study aimed at updating the information on the current status of
micronutrient fortification in mandatory food vehicles in Tanzania. A cross-sectional study was
conducted in 5 regions to analyze the adequacy of micronutrient fortification and identify
challenges facing fortification programs. Samples (from selected companies) of fortified edible
oil (n = 19), wheat flour (n = 12) and maize flour (n = 5) were collected from supermarkets and
analyzed for vitamin A, folic acid, iron and zinc using standard methods and procedures.
Questionnaires were used to identify challenges regarding fortification compliance. About 80%
and 83% of the maize and wheat flour samples respectively complied with the iron fortification
standards. Only 25% and 40% of the wheat and maize flour samples respectively complied
with zinc fortification. Nearly 17% and 20% of the wheat and maize flour samples and 10.5%
of the cooking oils respectively complied with folic acid and vitamin A standard. Significant
variations (p < 0.001) were observed in 5 batches of cooking oil, 1 batch of wheat flour and 2
batches of maize flour. Moreover, high cost of premixes (83%), low consumer awareness
(75%) and poor laboratory facilities (67%) were highlighted as barriers to food fortification
compliance. This shows that food fortification is still facing challenges in Tanzania and hence
calls for a review of the current fortification programs in Tanzania
Community-networks that facilitate engagement in health research: Ifakara Health Research Institute-Bagamoyo case study
Get PDFThis research article published by AAS Open Research, 2021Background: Involvement of communities in the field of health research has been at the forefront of what is considered as ethical conduct of research. A commonly used approach is regular meetings with locally recognized community leaders to consult about research activities, i.e. community engagement. At the Ifakara Health Research Institute (IHI) in Bagamoyo, Tanzania, different approaches to engaging with the community in health research have been used, but there has not been a systematic understanding of the functioning of the community network that is engaged within health research.
Methods: To understand the community networks engaged in health research, perceptions of community stakeholders and researchers on the functionality of the community networks was performed. We conducted six focus group discussions with respondents who have participated in IHI research for the past five years and 49 in-depth interviews.
Results: Community networks involved in engagement were influenced by the type of research project and kind of participants needed. Different community networks were involved in engagement activities, namely village executive officers, community health workers, hamlet leaders, nurses, doctors and community advisory boards. Approaches used during engagement processes to inform potential participants about the work of IHI and specific studies that are undertaken were useful in passing key information, however, they did not always reach the target population due to having limited levels of interaction with potential participants. Participants and researchers suggested additional ways to engage with the community.
Conclusion: There is a need of developing a community engagement unit that would work across projects to support engagement with the community. The unit will maintain continuous engagement with the community and conduct research to understand the relationship between communities we work in and researchers. Funding of this unit could be done through contributions from the core budget, individual’s projects or competitive grant application
Enhancing the performance of a spray flash evaporation integrated with evacuated tube desalination system
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Master’s in Sustainable Energy Science and Engineering of the Nelson Mandela African
Institution of Science and TechnologyNumerical analysis for heat exchanger for spray-assisted low-temperature desalination system
is presented for an existing low-temperature desalination unit at Arusha Technical College
(ATC). The current desalination unit at ATC has two suction fans and a water pump in the
condensation unit where significant amount of energy is consumed. So, it will be impractical
to implement such a type of desalination system in remote areas where there is limited access
to electricity. The study aims to come up with a suitable model for the replacement of the
current condensation unit due to high energy consumption. The heat transfer phenomena have
been analyzed to understand the effect of mass flow rate, tube length and diameter in a shelland-tube
heat exchanger (STHX). A Math CAD model was developed using the Delaware
method to obtain the mentioned parameters. The results show that the pressure drop is very
low from all STHX configurations, while the heat transfer coefficient seems to be maximum
in the smallest diameter within the largest tube length heat exchanger. The maximum possible
energy will be extracted by the STHX from the steam while it condenses. According to the
results, as long as over-design is considered the proposed system can be implemented with the
minimum effect of 5.968 to 10.688 kWh energy consumption. The energy-saving of the
proposed system is about 8.856 kWh as the replacement of the STHX from the existing
condensation unit. While the current system energy is consumed about 14.824 to 19.544 kWh
in a single day of operation. Also, the proposed system will improve the system workability to
the remote communities in future implementation
Assessment of the status of African Baobab populations and fatty acids composition of its crude oil in semi arid areas of Tanzania
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Philosophy in Life Sciences of the Nelson Mandela African Institution of Science and
TechnologyBaobab (Adansonia digitata L.) is a deciduous non-timber tree species that is facing severe
threats from both anthropogenic and climatic pressures across its range states. Additionally,
baobab seed oil has been used for many years by local populations as medicine to treat
different diseases, beauty, and food purposes. However, consumption of baobab seed oil has
been reported to cause health effects emanating from the presence of carcinogenic ingredients
known as Cyclopropenoid Fatty Acids (CFPAs). Ecological survey and laboratory analysis
were carried out to asses the status of Baobab populations and characterize their fatty acid of
seeds clued oil respectively. In ecological survey, stratified random sampling design
composed of the three land-use types: strictly protected areas, non-strictly protected areas,
and unprotected areas were used to select the grids for the study. Baobabs were sampled in
belt transect of 1 km long and a 50 m wide, which were carried out in 337 grids located in
three different land-uses types. In the laboratory analysis, the physico-chemical properties
were determined according to Official Methods of Analysis of the Association of Official
Analytical Chemists. The quantification of fatty acid before and after heating was done by the
analysis of derivative fatty acid methyl-esters by using Gas-Liquid Chromatography. Baobab
density was found to be highest in strictly protected areas (2.45 ± 1.29) and the lowest in
unprotected areas (1.52 ± 1.00). The density of adult, sub-adult and juvenile populations were
1.53 ± 0.105, 0.82 ± 0.149 and 0.33 ± 0.253 plants/ha respectively. Furthermore, the results
show bell shaped and inverse J-shaped distributions in the unprotected areas and strictly
protected areas, respectively. The number of baobabs damaged was higher than undamaged
in all land-use types. There were no significant differences in terms of physico-chemical
properties in three different regions. It was found that the baobab crude oil contains mainly
twelve essential fatty acids and two different CFPAs. The most abundant fatty acids were
Palmitic acid, Oleic acid and Linoleic acid in all the three regions. The major breakdown of
CPFAs started at 200 °C that would be the best temperature in the refining process of the
baobab oil. The findings from this study are important in understanding the status of baobab
populations and CPFAs of their crude oil in different land uses and serve to inform decision akers towards sustainable management of this species. Furthermore, the information from this
study is vital in understanding the role of biophysical conditions and land uses in shaping the
population persistence of the species in its range areas in Tanzania
Comparison of the effects of a broad-spectrum herbicide and a bio-herbicide on insect flower visitation in the Serengeti ecosystem, Tanzania
Get PDFThis research article published by Elsevier, 2021The functional role of insect visitors on flowering plants is crucial to both natural and agricultural ecosystems. While, few studies have addressed the impact of invasive plant species on insect visitors, even less is known about how management practices against invasive plants may affect plant-pollinator interactions. We assessed how natural versus chemical-based management against the invasive plant Gutenbergia cordifolia affected insect visitors in Mwiba area, Tanzania. We compared the number of insect visitors, diversity and richness, the number of inflorescences visited, inflorescences abundance and flower diversity across treatments of Desmodium uncinatum crude leaves extract (DUL), the chemical glyphosate (GLY), and none /control (CON). We found that more than half (55%) of the insect visitors observed were found visiting flowering plants in DUL plots, followed by CON with 26% and GLY plots with 19%. Further, DUL plots had almost twice as many inflorescences visited compared to CON and GLY plots. Inflorescence’s abundance and flower diversity were significantly higher in DUL plots compared to CON and GLY plots. Our study revealed that DUL treatment did not disrupt insect flower visitation but rather attracted more insects. We conclude that using the natural plant extract treatment is highly preferable to the chemical management of invasive plants such as G. cordifolia, as the DUL treatment maintained and even enhanced flower diversity while suppressing G. cordifolia and fostering insect visitors
Assessment of groundwater pollution in Singida urban and Manyoni districts
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Doctor of Philosophy in Environmental Sciences and Engineering of the Nelson Mandela
African Institution of Science and TechnologyThe quality of groundwater in Tanzania has over the years remained poorly understood, hence
posing risks to human health and the environment. In this study, the quality of groundwater
sources used for drinking purpose in Singida Urban and Manyoni districts were investigated with
a view to explore how the end users could be safeguarded from water borne diseases. Water
samples from 30 boreholes and 28 shallow wells were randomly collected during dry and wet
seasons. Water quality assessments were conducted following recommended guidelines by
Tanzania Bureau of Standards (TBS) and international standards (WHO) for drinking water.
Twelve physicochemical parameters were assessed using standard methods for water and
wastewater from American Public and Health Association (APHA). Microbial water quality (TC,
FC, and E.coli) were examined using membrane filtration technique while toxic metals were
determined using Inductively Coupled Plasma Optical Emission Spectrometer. Nitrate source
identifications were done using Elemental Analyzer/ isotope ratio mass spectrometry techniques.
Results showed that shallow wells recorded significant higher turbidity (p<0.0001) compared to
boreholes. The water samples collected during wet season had significantly higher microbial
contamination compared to those collected during dry season. Additionally, the wells were
buckets are used to draw water had significantly higher TC, FC and E.coli (n=11, p≤ 0.01), also
wells without covers (n=15, p≤0.01) had significantly higher feacal coliform bacteria than those
which motor or hand pump were used in both seasons. Concentration of toxic metals was
significantly higher (p<0.05) during the dry season than in the wet season and 40- 66% of all
samples had an elevated level of Mn, Cr, Pb, and Al above the recommended standards by World
Health Organization (WHO) and Tanzania Bureau of Standards (TBS), hence unsafe for
drinking. Nitrate sources identification revealed that, most nitrate contamination were originated
from sewage effluents and/or organic wastes such as manure. The study recommends that water
from shallow wells should be treated either by boiling, chlorination, or use of low cost
technologies such as sand filter before consumption. In addition, the proper sitting of the wells
based on the recommended standards by TBS has to be enforced in order to prevent further
contamination from human activities
Big data analytics framework for childhood infectious disease surveillance system using modified mapreduce algorithm: a case study of Tanzania
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Master’s in Information and Communication Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyTanzania has been affected with a potential emerging and re-emerging of infectious diseases such
as diarrhea, acute respiratory infections, pneumonia, hepatitis, and measles. There is an
increasing trend for the occurrences of new emerging pandemic diseases such as the coronavirus
(Covid-19) in 2020 as well as re-occurrence of old infectious diseases such as cholera epidemic
in 2015-2017, chikungunya and dengue fever outbreak in 2010, 2012, 2014, 2018, and 2019
which affected different regions in Tanzania. These diseases by far are the main causes of the
high mortality rate for women and children of 0-5 years of age. The traditional disease
surveillance system as the foundation of the public healthcare practices has been facing
challenges in data collection and analysis using health big data sources to prevent and control
infectious diseases. Health big data sources on infectious diseases have been recognized as the
potential supplement for the provision of evidence-based decision-making worldwide. Tanzania
as one of the resource-limited setting countries has lagged because of the challenges in
information technology infrastructure and public healthcare resources. The traditional disease
surveillance system is still paper-based, semi-automated, and limited in scope which relies on
clinical-oriented patient data sources and leaving out nontraditional and pre-diagnostic
unstructured big data sources. This research study aimed to improve the traditional infectious
disease surveillance system to employ big data analytics technology in healthcare data collection
and analysis to improve decision-making. Big data analytics framework for the childhood
infectious disease surveillance system was developed which guides healthcare professionals to
streamline the collection and analysis of health big data for infectious disease surveillance. The
framework was then fairly compared with the existing framework in its performance using
infrastructures, data size and transformation, and running-time execution of the systems. The
experimental results indicate the efficiency of the framework system performance with the
highest running time execution of about 56% quicker over the traditional system. Also, it has the
best performance in processing multiple data structures using additional processing units. In
particular, the proposed framework can be adopted to improve the prenatal and postnatal
healthcare system in Tanzania
A Deep Learning-based Mobile Application for Segmenting Tuta Absoluta’s Damage on Tomato Plants
Get PDFThis research article was published by Engineering, Technology & Applied Science Research, Volume: 11, Issue: 5, October 2021With the advances in technology, computer vision applications using deep learning methods like Convolutional Neural Networks (CNNs) have been extensively applied in agriculture. Deploying these CNN models on mobile phones is beneficial in making them accessible to everyone, especially farmers and agricultural extension officers. This paper aims to automate the detection of damages caused by a devastating tomato pest known as Tuta Absoluta. To accomplish this objective, a CNN segmentation model trained on a tomato leaf image dataset is deployed on a smartphone application for early and real-time diagnosis of the pest and effective management at early tomato growth stages. The application can precisely detect and segment the shapes of Tuta Absoluta-infected areas on tomato leaves with a minimum confidence of 70% in 5 seconds only