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Estimating the risk of aflatoxin-induced liver cancer in Tanzania based on biomarker data.
Get PDFThis research article published by PLOS ONE, 2021Evidence about the magnitude of the aflatoxin menace can help policy makers appreciate the importance of the problem and strengthen policies to support aflatoxin mitigation measures. In this study, we estimated aflatoxin-induced liver cancer risk in 2016 for Tanzania and used the information to estimate the health burden due to the aflatoxin exposure in the country. The burden of aflatoxin-induced liver cancer was assessed based on available aflatoxin biomarker data from a previous epidemiology study, hepatitis B virus infection prevalence and population size of Tanzania in 2016. The health burden due to aflatoxin-induced liver cancer was estimated using disability adjusted life years (DALYs). The aflatoxin exposures ranged from 15.0-10,926.0 ng/kg bw/day (median, 105.5 ng/kg bw/day). We estimated that in 2016 there were about 1,480 (2.95 per 100,000 persons) new cases of aflatoxin-induced liver cancer in Tanzania and assumed all of them would die within a year. These morbidity and mortality rates led to a total loss of about 56,247.63 DALYs. These results show, quantitatively, the cases of liver cancer and related deaths that could be avoided, and the healthy life years that could be saved, annually, by strengthening measures to control aflatoxin contamination in Tanzania
Effect of lactic acid fermentation of watermelon juice on its sensory acceptability and volatile compounds
Get PDFThis research article published by Elsevier Ltd., 2021Fermentation increases food shelf-life but is characterized by changes that affect product's perception. Watermelon juice was fermented with Lactobacillus plantarum (WJ-LP), L. rhamnosus (WJ-LR), L. casei (WJ-LC), L. brevis (WJ-LB) and Pediococcus pentosaceus (WJ-PP). Their sensory characteristics and volatile compounds were investigated by consumers and Headspace Solid Phase Microextraction integrated with Gas Chromatography-Mass Spectrometry, respectively. WJ-PP and WJ-LB were most liked and perceived with ‘watermelon-flavor’, ‘natural taste’, ‘sweet’ and ‘watermelon-color’ while WJ-LC, WJ-LP and WJ-LR were least liked and perceived as ‘sour’, ‘bitter’, ’off-flavor’, ‘aftertaste’ and ‘intense-flavor’. Fifty-four volatiles were identified. After fermentation, alcohols, ketones, monoterpenes, acids, and furans increased while aldehydes and alkanes decreased. Lactic acid fermentation introduced 4-decanone and 2,3-butanedione in WJ-LB, WJ-LC, WJ-LP and WJ-LR, however, heptanal, 2-heptenal, 2,6-nonadienal, 2-decenal, and 2,4-decadienal in WJ-LC, heptanal, 2-hexenal, 2-heptenal, 2,6-nonadienal, 2-decenal and octanal in WJ-LR and 2,6-dimethyl-2,6-octadiene in WJ-LP disappeared. Juice sensory profiles were associated with their volatile compounds
Fatty Acid Contents and Stability of Oyster Nut Oil (Telfairia pedata) Compared to Flaxseed and Sunflower Oil
Get PDFThis research article was published by Hindawi, 2021The selection of healthy fats for consumption is important. Linoleic acid (LA) (omega-6) and alpha-linolenic acid (ALA) (omega-3) are essential polyunsaturated fatty acids required for the maintenance of good health; however, LA derivatives such as arachidonic acid (AA) are associated with the onset of inflammatory diseases, and both are prone to oxidation and deterioration. This study compared the fatty acid contents, peroxide value (PV), p-anisidine value (p-AV), and free fatty acids (FFA) of the oyster nut oil with refined sunflower, nonrefined sunflower, and flaxseed oil stored at 27°C for 40 days. Flaxseed oil had significantly high ALA content (59.8%) compared to 0.1-0.5% for oyster nut and sunflower oil brands. The LA content was high in sunflower brands (50.3-52.8%) compared to the oyster nut (48%) and flaxseed oil 14.7%. Oleic acid was lower in oyster nut oil (8.6%) and flaxseed oil 15.8% compared to sunflower brands (35.7-38.2%). As a consequence, oyster nut and flaxseed recorded higher PV of 4.35-2.88 mEq O2/kg and FFA 0.26-0.47% compared to sunflower brands. The p-AV recorded small values which were not significantly different in all samples. Although oyster nut is widely consumed by pregnant and lactating women across Africa, its keeping quality in nonrefined form is low compared to flaxseed and sunflower oil as shown in this study. Hence, the fatty acid contents in oyster nuts should be consumed in other alternative forms such as flour and roasted kernels rather than its oil when in nonrefined form. This study will enable the consumption balance of omega-6/omega-3 fatty acids and the keeping quality of oils which is key to health
Ethical Considerations of the Trial to Establish a Causal Linkage Between Mycotoxin Exposure and Child Stunting
Get PDFThis research article was published by Elsevier, 2021Objectives
Aflatoxins are fungal metabolites that commonly contaminate staple crops in tropical regions. Aflatoxin is a carcinogen and consumption at high-levels can lead to acute liver failure and aflatoxicosis. Multiple epidemiologic studies have shown an association between aflatoxin exposure in infants and young children and growth failure, but strong experimental evidence is lacking. The Trial to Establish a Causal Linkage Between Mycotoxin Exposure and Child Stunting being conducted in Tanzania is a cluster-randomized trial to assess the effect of reduced aflatoxin exposure on linear growth.
Methods
Prior to its design and launch, the multi-disciplinary research team conducted a critical review to determine the most salient ethical questions and dilemmas in the potential conduct of such a study and debated if and how this study could be designed to meet human subject ethical criteria. This critical review included trial protocols, methodologies and historical controversies in the areas of bio-medical, public health and environmental health research.
Results
This critical review identified three major questions: 1) Given what is already known about aflatoxin, should a question about the effect of this toxin on child growth be studied further in human subjects? 2) If the relationship between aflatoxin and stunting can be studied in humans, what is the most ethical study design to employ? 3)What is the most ethical intervention to randomly allocate?
Conclusions
Based on the critical review and in alignment with human subject principles and guidelines, we concluded that it was possible to conduct such a study. The trial and intervention were designed to advance scientific knowledge, maintain a favorable risk/benefit ratio, and respect participants, among other ethical principles
Isotopic and hydrogeochemical characterization of groundwater and surface water from a mine site in Tanzania
Get PDFThis research article published by IWA publishing, 2021This study used the hydrochemical properties of water to reveal the causes of water quality degradation. The results showed that most samples located downstream of the mine tailings dam were slightly acidic with pH as low as 4.6. Samples with high levels of Na+, Cl−, and could not be isotopically linked to the local geochemistry, but the anthropogenic activities and evaporation were probably responsible for the observed water chemistry. The Piper diagram indicated cations were dominated by Ca and Mg, while anions were dominated by bicarbonates and sulphates. Pb and Hg levels (mean 70.29 and 17.95 μg/L, respectively) were all higher than the World Health Organization (WHO) and Tanzanian drinking water guidelines. Mining activities probably contributed to the observed low pH values and elevated concentration of cyanides, heavy metals, and metalloids. Stable isotope results indicated a vulnerability of the water to recent contamination that could be attributed to anthropogenic activities. Moreover, isotopic studies indicated a flow pattern from the eastern to the western side of the mine study site. Lowland samples were more 3H-enriched than highland ones. The present study concludes that groundwater recharge from recent local precipitation may have an impact on the sources studied
Health Benefits of Antioxidative Peptides Derived from Legume Proteins with a High Amino Acid Score
Get PDFThis research article published by MDPI, 2021Legumes such as soybean, chickpea, lentil, cowpea, and mung bean, are valuable sources
of protein with a high amino acid score and can provide bioactive peptides. This manuscript presents
a review on legume-derived peptides, focusing on in vitro and in vivo studies on the potential
antioxidative activities of protein hydrolysates and their characterization, amino acid sequences,
or purified/novel peptides. The health implications of legume-derived antioxidative peptides in
reducing the risks of cancer and cardiovascular diseases are linked with their potent action against
oxidation and inflammation. The molecular weight profiles and amino acid sequences of purified
and characterized legume-derived antioxidant peptides are not well established. Therefore, further
exploration of legume protein hydrolysates is necessary for assessing the potential applications of
antioxidant-derived peptides in the functional food industry
Use of lay vaccinators in animal vaccination programmes: A scoping review
Get PDFThis research article was published in PLoS, Volume 2, 2021.Background
The human resource gap in veterinary sectors, particularly in low-income countries, imposes limitations on the delivery of animal healthcare in hard-to-reach populations. Lay animal health workers have been deployed in these settings to fill the gap though there are mixed views about the benefits of doing this and whether they can deliver services safely. We mapped evidence on the nature and extent of roles assigned to lay animal vaccinators, and identified lessons useful for their future deployment.
Methodology/Principal findings
Following the PRISMA Extension for Scoping Reviews guidelines, we searched seven bibliographic databases for articles published between 1980 and 2021, with the search terms lay OR community-based OR volunteer AND "animal health worker" OR vaccinator*, and applied an a priori exclusion criteria to select studies. From 30 identified studies, lay vaccinators were used by non-government developmental (n = 12, 40%), research (n = 10, 33%) and government (n = 5, 17%) programmes to vaccinate domestic animals. The main reason for using lay vaccinators was to provide access to animal vaccination in the absence of professional veterinarians (n = 12, 40%). Reported positive outcomes of programmes included increased flock and herd sizes and farmer knowledge of best practice (n = 13, 43%); decreased disease transmission, outbreaks and mortality (n = 11, 37%); higher vaccination coverage (10, 33%); non-inferior seroconversion and birth rates among vaccinated herds (n = 3, 10%). The most frequently reported facilitating factor of lay vaccinator programmes was community participation (n = 14, 47%), whilst opposition from professional veterinarians (n = 8, 27%), stakeholders seeking financial gains to detriment of programmes goals (n = 8, 27%) and programming issues (n = 8, 27%) were the most frequently reported barriers. No study reported on cost-effectiveness and we found no record from a low and middle-income country of lay vaccinator programmes being integrated into national veterinary services.
Conclusion
Although the majority of included studies reported more benefits and positive perceptions of lay vaccinator programmes than problems and challenges, regularization will ensure the programmes can be designed and implemented to meet the needs of all stakeholder
Mathematical modeling of COVID-19 transmission dynamics between healthcare workers and community
No full textA research article was submitted to Results in Physics Volume 29, October 2021Corona-virus disease 2019 (COVID-19) is an infectious disease that has affected different groups of humankind
such as farmers, soldiers, drivers, educators, students, healthcare workers and many others. The transmission
rate of the disease varies from one group to another depending on the contact rate. Healthcare workers are
at a high risk of contracting the disease due to the high contact rate with patients. So far, there exists no
mathematical model which combines both public control measures (as a parameter) and healthcare workers
(as an independent compartment). Combining these two in a given mathematical model is very important
because healthcare workers are protected through effective use of personal protective equipment, and control
measures help to minimize the spread of COVID-19 in the community. This paper presents a mathematical
model named SWE
HR; susceptible individuals (S), healthcare workers (W), exposed (E), symptomatic
infectious (
), asymptomatic infectious (
), hospitalized (H), recovered (R). The value of basic reproduction
number 0
for all parameters in this study is 2.8540. In the absence of personal protective equipment and
control measure in the public , the value of 0 ≈ 4.6047 which implies the presence of the disease. When
and were introduced in the model, basic reproduction number is reduced to 0.4606, indicating the absence
of disease in the community. Numerical solutions are simulated by using Runge–Kutta fourth-order method.
Sensitivity analysis is performed to presents the most significant parameter. Furthermore, identifiability of
model parameters is done using the least square method. The results indicated that protection of healthcare
workers can be achieved through effective use of personal protective equipment by healthcare workers and
minimization of transmission of COVID-19 in the general public by the implementation of control measures.
Generally, this paper emphasizes the importance of using protective measures
Effect of mixing ratios of natural inorganic additives in removing ammonia and sulfide in the liquid phase during anaerobic digestion of slaughterhouse waste
Get PDFThis research article was published in Materials Today Chemistry, Volume 20, 2021.In this study, the efficacy of inorganic additives in the removal of total ammonia nitrogen (TAN) and sulfide in the aqueous phase of slaughterhouse waste undergoing anaerobic digestion in the batch reactor was investigated. A mixture of natural inorganic additives processed from the anthill and red rock soil samples collected from Arusha, Tanzania were used as adsorbents in different ratios. These materials were chosen in regard to their abundance in the local environment, surface properties, and elemental composition. Before analysis, the materials were pulverized and calcined at 700 and 900 °C for 2 h in a furnace and then sieved to 250 μm fine particle size. XRD analysis revealed that the anthill soil sample is endowed with major mineral phases of quartz and hematite while red rock soil contains albite, pyroxene, and quartz as predominant phases. The anthill and red rock soil samples calcined at 900 °C displayed higher BET surface areas of 815.35 and 852.35 m2/g, respectively. The mixture of anthill soil and red rock soil in a ratio of 3:1 had a higher TAN removal efficiency of 92% at a contact time of 30 min compared to other ratios. On the other hand, a ratio of 1:2 showed a higher sulfide removal efficiency of 79% at a contact time of 60 min. Adsorption isotherm studies revealed that the Jovanovich model fitted better to the experimental data than the Langmuir and Freundlich models. The results demonstrated further that inorganic additives have a synergistic effect on stimulating methanogenesis as well as eliminating ammonia and sulfide during anaerobic digestion of slaughterhouse waste. Our findings demonstrate that anthill and red rock soils can be exploited as affordable, ecofriendly, and efficient adsorbents for mitigation of TAN and sulfide from the liquid phase and sustenance of methanogenesis
Solvent effects on host-guest residence time and kinetics: further insights from metadynamics simulation of Toussaintine-A unbiding from chitosan nanoparticle
Get PDFThis research article was published in the Journal of Molecular Modeling Volume 27, 2021Solvents play an important role in host-guest intermolecular interactions. The kinetics and residence time of Toussaintine-A (TouA) unbinding from chitosan was investigated by means of well-tempered metadynamics and thermodynamic integration using two solvents, polar aprotic (DMSO), and polar protic (water). The kinetic rates were found to be strongly dependent on the solvent polarity; hence, the unbinding rate proceeded much faster in DMSO compared to water. DMSO tends to participate less in a chemical reaction by weakening the intermolecular interaction between chitosan and TouA due to lack of acidic hydrogen resulting in a reduction of the transition state. On the other hand, water, which ought to donate hydrogen atoms, sustains a strong interaction and hence large barrier heights. Consequently, this reduces the unbinding rate and increases the residence time. Binding free energy from thermodynamic integration suggests a thermodynamic stable chitosan-TouA complex in water than in DMSO