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Hypoglycemic Effects of Cymbopogon citratus Ethanol Leaves' Extract and Its Fractions in Alloxan-Induced Diabetic Mice 2020
Get PDFThis research article was published by International Journal of TROPICAL DISEASE & Health Volume 41, 2020Varieties of plants, including Cymbopogon citratus, are traditionally used in controlling hyperglycemia by either stimulating insulin secretion, inhibition α- Glucosidase or α-amylase activity. This study evaluated hypoglycemic effects of Cymbopogon citratus ethanol leaves' extract and its fractions in alloxan-induced diabetic mice. Cymbopogon citratus leaves were shade dried, grinded into fine powder and then extracted by cold maceration using ethanol. Fractionation was done by VLC using dichloromethane, ethyl acetate and ethanol. OGTT was performed for both crude extract and fractions. Diabetes was induced in mice by intraperitoneal injection of freshly prepared alloxan monohydrate (170 mg/kilogram body weight). The mice were treated with ethyl acetate fraction once daily at 400 mg/kilogram body weight dose for the period of 20 days.FBG and weight were then recorded in days 1, 5, 10, 15 and 20 after six hours of fasting. Safety of crude water extract and ethyl acetate fractions were evaluated in mice by using Lorke’s method, followed by 5 days observation for their mortality and behavioral changes. Comparisons of results among groups were analyzed using One-way ANOVA. The difference between the means of the two population groups (each against negative control) was considered significant at p< 0.05. Results were expressed as mean ± SD. Both crude and ethyl acetate fractions from C. citratus showed significant hypoglycemic activity. Moreover, higher hypoglycemic activity was shown by ethyl acetate fraction (p = 0.004). No mortality was observed at 5000 mg/kilogram body weight dose but sleeping and tremor were observed at a 1000 -5000 mg/kilogram body weight dose. Good hypoglycemic and safety results from ethyl acetate fraction highly suggest that Cymbopogon citratus extracts are effective against insulin-dependent hyperglycemia, which may be contributed by the action of screened alkaloids, saponins, antraquinone, phenol and tannins. Isolation and testing of the active ingredients from the C. citratus extract are thus warranted for use in developing pharmaceutical anti-hyperglycemic drugs from this herbal plant
Dolichos Lablab-an underutilized crop with future potentials for food and nutrition security: a review.
Get PDFThis research article published by Taylor & Francis Online, 2020Achieving the Sustainable Development Goals (SDGs) particularly goal number two in developing countries by 2030 is challenging. The State of Food Security and Nutrition (2019) in the World show prevalence of undernourishment which has practically remained unchanged for the last three years. This calls for sustainable synergies between food and nutrition in addressing the challenge. Exploring the potential of underutilized legumes such as Dolichos Lablab () in improving food and nutrition security is of importance. Lablab is known among nutritious underutilized diversified legumes, which is drought tolerant relative to other legumes. However, it is less popular as human food. This review focuses on providing details on the nutritional potential of underutilized Lablab varieties for food availability, accessibility and satisfactorily utilization for improved livelihood. So far research attention has been focusing on good agronomic performance with less information on their nutritional quality and its contribution to the wellbeing of people. Both wild and cultivated Lablab accessions do differ morphologically and across diverse habitat environments. This may make them less known, untapped and underutilized despite its promising potential as a food resource in developing countries where malnutrition still exists. Efforts are needed to popularize high-quality nutritional accessions, enhancing their consumption and commercialization for feeding the ever-increasing population in the future
Oxidative stree management is essential for anopheles mosquito survival post plasmodium infected blood meal ingestion
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of
Doctor of Philosophy in Life Sciences of the Nelson Mandela African Institution of Science
and TechnologyAnopheles mosquitoes like other dipterans lack the flavoenzyme glutathione reductase (GR) of the
GSH pathway and instead utilize the Thioredoxin (Trx) system for management of oxidative stress.
Anopheles gambiae (An. gambiae) and Anopheles stephensi (An. stephensi) mosquitoes have been
shown to regulate genes and proteins of the Trx system to protect midgut epithelial cells against
reactive oxygen/nitrogen species (ROS/RNS) associated with Plasmodium berghei (P. berghei)
infection. However, this mosquito vector-parasite combination is not natural and may not
necessarily reflect human malaria transmission biology in the field. Despite its importance, a
complete understanding of the Trx pathway at the molecular level is missing.
Mosquito feeding assays were used to examine the Trx response pathway following midgut
exposure to ROS/RNS, by measuring first the protein expression level of Thioredoxin-1 (AgTrx1)
post
exposure to tert-Butyl hydroperoxide (tBHP) by quantitative immunoblot analysis. This
was followed by measuring the global proteomic response to Paraquat (Pqt) and tBHP exposure.
The proteomic response was then compared to a spectrum of Trx- and GSH-dependant transcripts
24 hours post-infected bloodmeal ingestion in the more natural vector-parasite combination of An.
gambiae-Plasmodium falciparum (P. falciparum) to assess for: (a) concordance between protein
and transcript under different oxidative conditions and (b) similarity to the unnatural vectorparasite
(An. gambiae/An. stephensi-P. berghei). It was observed that protein levels of AgTrx-1
remained unchanged in midgut epithelial cells exposed to different concentrations of tBHP.
Moreover, proteomics profiles of midgut epithelial cells under tBHP-and Pqt-induced oxidative
stress showed cells that are undergoing redox regulation through ribosomal/nucleolar and ERstress
responses, respectively. This response is contrary to the canonical antioxidant response
previously described. Furthermore, transcript data showed an absence of significant upregulation
in the Trx- and GSH-dependent genes. This is consistent with the concept that P. falciparum does
not induce marked midgut destruction in An. gambiae, therefore its invasion process is associated
with reduced oxidative stress.
The ribosomal/nucleolar and ER stress responses to oxidative stress suggest additional response
mechanisms to the canonical antioxidant responses. These additional responses could be translated
to develop strategies that could lead to unmanageable levels of ROS/RNS exposure to the parasite in the midgut, yet still allowing the mosquito to survive the dysregulation. This would lead to a
stop in parasite development leading to blocking of transmission
Assessing soil fertility status and pest infestation levels in selected banana growing regions of Tanzania
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of
Master’s in Life Sciences at the Nelson Mandela African Institution of Science and
TechnologyZanthoxylum chalybeum (Rutaceae) is subject to heavy exploitation throughout its areas of
occurrence in Sub-Saharan Africa. Despite being a common medicinal plant utilized by a large
population, little has been documented regarding the constraints which hinder its promotion and
conservation concerns within the country. This study was conducted to determine distribution and
conservation challenges facing medicinal plant Zanthoxylum chalybeum on different land uses
types surveyed at Simanjiro area. The most available roads were used as line transects to observe Z.
chalybeum distribution in the study area. Plots were established for data collection whereby GPS
coordinates (tree presence- absent), tree numbers and anthropogenic threats were the collected
information. In addition, open-ended, semi-structured questionnaires and focused group
discussions (FGD) were used to capture information on the uses, availability, conservation
challenges and management of the plant in the study area. Results indicated that the distribution
of Z. chalybeum in the area differ significantly across the land-use types surveyed in this study by
having many trees in hunting blocks within game-controlled areas and open areas (49 and 40
respectively). Anthropogenic threats signs observed included debarking (51%), branch cut
(20.6%) and root digging (15.8%). It was observed that the majority of the households use Z.
chalybeum for gynecological diseases (such as blood loss after labor, menstrual pain, early
pregnancy complications) (86.4%). The main conservation challenges included unsustainable
change in land use (99.9%) and inadequate conservation education and awareness. This study
recommends more conservation efforts such as active planting of the species, regulated utilization
of the Z. chalybeum species and increased education and awareness to be implemented by
authorities in game-controlled areas and open areas and also conservation education should be
provided to members of the community
Identification of multiple unknown point sources occurring in the 2D transport equation: application to groundwater pollution source identification
Get PDFThis research article published by the Journal of Mathematical and Computational Science, 2020Water loss in the water distribution systems (WDS) is a challenge to many
water authorities in the world but the problem is crucial in the less developed countries.
The effect of water losses in the WDS includes the reduction in the revenue and
availability of water, interruption in the quality of water, and inflation of the operation
and maintenance cost of the water authorities. Using data from the Moshi Urban Water
Supply and Sanitation Authority (MUWSA) Tanzania, an assessment of strategies used
for water loss management (WLM) was carried out through an integrated model of MultiCriteria Decision Making (MCDM) and Integer Linear Programming (ILP) which is an
optimisation technique. The family of MCDM methods, Multi-Attribute Value Theory
(MAVT), Simple Multi-Attribute Rating Technique Exploiting Ranks (SMARTER), and
Simple Additive Weighting (SAW) were employed to assess and prioritise the strategies
while the ILP was used to formulate a decision model. The model was used to select a
portfolio of the best strategies. Sixteen strategies were identified. The results show that
the comparison between the bulk meter and customers’ meter on detecting the physical or
apparent losses was ranked as the best strategy in managing the loss while the network
zoning was ranked as the worst strategy. The model selected thirteen out of sixteen
strategies to form the portfolio of the best strategies to be employed by the MUWSA for
water loss management. Furthermore, the model was found to be robust as the selected
portfolio of strategies remained the same even when the weights of the criteria were
changed. The developed model in this study will assist the decision-makers to assess,
prioritise and choose the best strategies for reducing or controlling water loss in the
distribution system
A retrospective study on the epidemiology and trends of road traffic accidents, fatalities and injuries in three Municipalities of Dar es Salaam Region, Tanzania between 2014-2018
Get PDFThis research article published by Pan African Medical Journal, 2020Introduction: Over 90% of injuries and deaths still occur in low and middle-income countries like Tanzania due to Road traffic accidents. Available literature indicates that Tanzania suffers massive human and economic losses every year from RTAs despite several interventions that have been made to curb this scourge. To gain an insight into the current state of RTAs we examined the pre- historical case fatality rates from RTAs in Ilala and two other municipalities (Kinondoni and Temeke) in Dar es Salaam Region, Tanzania.
Methods: We conducted a retrospective study using the secondary data on road accidents from Road Accident Information System (RAIS) for the period 2014 to 2018.
Results: A total of 6,772 road traffic injuries were reported between 2014 and 2018 and the study recorded the highest RTAs in the year 2014 as compared to the other years within the study period. The death rate from RTAs in Ilala Municipality alone was 36.4 per 100,000 population. About 28% of the total fatalities were recorded among the pedestrians, and there was a significant difference (P < 0.05) in the RTAs among the other road users.
Conclusion: The study recommends the improvement of road transport infrastructure to ensure safety for all the road users by implementing the existing policies, strengthening the enforcement of existing legislation and introducing express penalties on a real-time basis. We encourage the use of this data to develop strategies in Tanzania that protect pedestrians and other vulnerable road users from RTAs
Removal of hydrogen sulfide from biogas using red rock materials
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Master’s in Materials Science and Engineering of the Nelson Mandela African
Institution of Science and TechnologyIn this study, the potential of red rock materials for the removal of hydrogen sulfide from biogas
was studied. The rock samples were collected, sieved and organized in various particle size
ranges such as 0.32 - 250 µm, 250 - 500 µm, 500 - 750 µm, 750 µm – 1.0 mm and 1.0 - 1.5
mm. These samples were calcined at temperatures of, 500 °C, 750 °C and 1000 °C and then
characterized for phase composition by Energy Dispersive X-ray Fluorescent, for surface area
by the Brunauer-Emmett-Teller method and surface morphology by Zeiss Ultra Plus Field
Emission Scanning Electron Microscopy. The calcined red rock was filled in the bed reactor,
and biogas was allowed to pass through the adsorbent while recording the inlet and exit
concentration of hydrogen sulfide. The results show that particle size, calcination temperature,
adsorbent mass and biogas flow rate influence the removal efficiency and adsorption capacity
of red rock. The sample sieved at 0.32 - 250 µm, and calcined at temperature 1000 °C showed
high removal efficiency 95% and adsorption capacity of 0.37 g/100 g of the sorbent.
Regeneration of spent materials when exposed to air, followed by reuse in the column,
appeared to have nearly similar removal efficiency as the original calcined sample. Thus, the
overall performance of the materials is promising, which is due to the presence of metals like
iron. Therefore, proving the red rock is available material it can be considered as a suitable
adsorbent for biogas purification.
Keywords: Red rock, Nadosoito, H2S removal, calcination, flowrate and particle siz
Low-cost far-field wireless electrical load monitoring system applied in an off-grid rural area of Tanzania
Get PDFThis research article published by Elsevier Ltd., 2020Despite the rapid development of Internet of Things (IoT) technology, there is still a lack of practical wireless energy monitoring methods that can be implemented directly in rural areas with undeveloped infrastructure. To address this gap, this paper presents a novel far-field wireless electrical load monitoring system. By taking advantage of radio frequency (RF) technology, the system realizes one-point-to-multipoint and multichannel communication, thereby extending the effective communication distance of the system and improving its sustainability to the influence of the external environment. The design proposed in this study includes standby equipment to effectively ensure the normal operation of the system in the case of hardware malfunction. The proposed method can be implemented in most geographical regions, neither confined to specific geographic locations nor limited by the level of development of the local infrastructure. Moreover, the hardware of the proposed system is based on Arduino boards, resulting in a low-cost manufacturing process. This system has been applied in a rural area of Tanzania, with 46 households. This paper reports a 238 % increase in power consumption by the residents between the time of initial system deployment, when they had little access to electricity, and the time when accessibility became easy
Modeling the transmission dynamics of bovine tuberculosis with control parameters
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Master’s in Mathematical and Computer Sciences and Engineering of the Nelson
Mandela African Institution of Science and TechnologyBovine tuberculosis (bTB) is a bacterial and zoonotic disease which is transmitted through;
consumption of unpasteurized milk, raw meat and inhalation of aerosols. This study used a
deterministic mathematical model to assess the impact of each parameter in the transmission
of bTB. The basic reproduction number R
computed to determine the behaviour of the disease.
The disease-free equilibrium exists and is locally asymptotically stable when R
0
< 1,
and it is unstable otherwise. However, there is a possibility for the diseases free equilibrium to
coexist with endemic equilibrium when R
= 1. The parameters which drive the dynamics of
bTB computed and sensitivity analysis performed. The analysis shows that the basic reproduction
number R
0
0
increases proportionally as the most positive sensitive parameters are increases.
However, the rate of animal deaths due to the disease mortality, the rate of natural animal deaths
and the rate of leaking for unused dairy products are conversely proportional to the basic reproduction
number R
. Numerical analysis performed to analyse how sensitive each parameter is
to the disease. Results show that bTB will increase when we increase rates of consuming dairy
products and contacts with infected humans and animals, respectively. The basic model then
extended by including control parameters to reduce bTB transmission. The effective reproduction
number R
e
0
decreases as we increase treatment of infected humans, quarantine of infected
animals and inspection of the dairy product. However, the standard requirement of effective
reproduction number Re to be less than a unit for the disease to clear is not enough because the
model undergoes backward bifurcation when R
= 1. Numerical analysis carried out to study
the long term behaviour of bTB. Simulations show that when control parameters increase, the
number of susceptible humans and animals increases, while the number of infected humans and
animals decreases. To contained Bovine tuberculosis, there should be the treatment of infected
humans, are quarantine of infected animals and dairy products should be inspected
Development of electronic fiscal device stock tracking module to monitor tax evasion in 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 TechnologyThe Electronic Fiscal Device (EFD) Machines have been operating in Tanzania since the year
2010 for the purpose of helping the Tanzania Revenue Authority (TRA) to increase revenues
from tax collection. Regardless of years of its existence, there are still reported cases of tax
evasion and this study was conducted to review the current tax collection system and analyze
requirements for the development of Stock Tracking Module (STM) to be embedded in the
current tax collection system. Data collection was done in Kilimanjaro and Arusha the two
regions of Tanzania involving tax officers and Information Technology (IT) personnel from
TRA regional offices. This study opted pharmaceutical business as case study due to its
sensitivity to human health and the fact that, its regulatory authority’s database can be linked
with the developed system to track expired and fake drugs in the market. Data collection
process involved quantitative and qualitative methods to gather information for the
development of the system’s Stock Tracking Module (STM) such as interview, questionnaire,
role-playing and observation. The study earmarked some problems relating to Electronic Fiscal
Device Machine Management System (EFDMS) and EFD machine. The major problems
encountered by TRA are; under declaration of sales by traders, non-usage of EFD machines,
usage of fake EFD, overestimate of expenses, division of business and conducting business in
unknown areas. The main outcomes of the study: The efficiency of the EFDMS was at average,
thus, needed some improvements. Therefore, this study developed an enhanced EFD system
by introducing stock tracking capabilities to monitor traders’ actions that translate to tax
evasion in such ways as; underpricing of sales value, avoid using the EFD machine and use of
fake EFD system which consequently increase government revenues