77 research outputs found
Striding towards self sustainability using Aluminium from Tanzanian kaolin for combination Tanning system
Content:
Sustainability is a key factor which control future leather manufacture. Developing several new technologies is one of the primary agenda for sustainability. However, developing countries are facing
several challenges which not only limited to best practice technologies but also finding self sustainability in maximizing the available resources. In the present study, an attempt has been made to explore the
potential resource of aluminium from kaolin of Pugu hills, Tanzania for combination tanning. Though, extraction of aluminium from several resources are available, there is limited literature pertaining to
Tanzania resources. Moreover, the extracted aluminium is basified and studied for its tanning efficiency.
Diffraction and vibrational spectroscopic studies were carried out to assess the confirmation of extracted aluminium. Combination tanning has been carried out with vegetable tannins and dialdehyde starch
tanning chemicals, which are from natural resources. Leathers tanned with aluminum and wattle resulted with a shrinkage temperature of 118ºC as compared to Al-Dialdehyde starch leathers showed around
90-100ºC. Physical strength characteristics such as tensile, tear and grain crack strength met the standard norms. Grain surface of leathers are found to be smooth which has been confirmed through microscopic studies. The study provides a new insight on accomplishing self sustainability through available resources and manufacture of eco-friendly system.
Take-Away:
1. Tanzania is endowed with massive kaolin rich in aluminium, which is potential for application in leather industry for sustainable development of leather industry
2. The combination tanning system using aluminium from Tanzania kaolin with wattle tannins or Dialdehyde starch imparts leather with both physical and organoleptic properties that meet the stipulated norms
3. This new tanning system provides new insight on ecofriendly tanning system for the sustainability of leather industry
Genetic diversity study of Kenyan cassava germplasm using simple sequence repeats
Cassava (Manihot esculenta Cranzt) is an important food security crop for resource poor rural communities particularly in Africa. Little is however known about molecular diversity of Kenyan cassava germplasm. This led to a study whose objective was to identify genetic constitution of cassava accessions from different regions of Kenya using molecular tools. Seven pairs of micro satellite (SSR) primers previously developed from cassava were used to detect polymorphic 21 alleles in a sample of 69 accessions. The cluster analysis of similarity matrix obtained at 68% with SSR data showed that the 69 accessions were grouped into five marker based groups. This study proved that SSRs could be used to identify cassava accessions as well as in the assessment of level of genetic relatedness among accessions.Keywords: Cassava, simple sequence repeat (SSR) markers, genetic diversity
Estimating Conveyance Efficiency and Maize Productivity of Traditional Irrigation Systems in Usa River Catchment, Tanzania
This research article published by Hindawi, 2020Estimating the conveyance efficiency of traditional irrigation schemes systems is very important. It is because of understanding the
volume of water lost along with the transportation facility, enhancing water usage and productivity, hence making better decisions
about the utilization of water resources. (e objective of the study was to determine water abstraction permit compliances and
estimate conveyance efficiency and crop and water productivity of traditional irrigation systems in northern Tanzania. (e task
involved measurement of irrigation water flows to determine the amount of water abstraction, inflow (head) and outflow (tail)
between the canals to determine the conveyance efficiency of the main, secondary, and tertiary canals of the traditional irrigation
systems. Moreover, water and yield obtained at the farm level were determined. Results indicate that approximately 72% of water
transported reaches the destined farm which produced maize (Zea mays L) yields of 1054.5 kg/ha, 892.4 kg/ha, and 875.156 kg/ha
at downstream, midstream, and upstream which equals 0.41 kg/m3, 0.15 kg/m3, and 0.09 kg/m3, respectively, while about 28% of
water is lost along the canals through evaporation, seepage, and deep percolation and overtopping. Consequently, water measured
at furrow intakes in total was 3, 500 L/s, equal to 23% more than the permitted amount of 2856.14 L/s at Usa River Catchment.
Interventions to minimize water losses starting at the furrow’s intakes are urgently required in the current trend of the increasing
demand for water resources for food production and schemes performance. Subsequently, more effective conveyance technologies
and water management strategies other than canal lining are required
MALT QUALITY AND STEM RUST RESISTANCE OF SELECTED BARLEY GENOTYPES IN KENYA
ABSTRACT Stem rust, caused by (Puccinia graminis f.sp. tritici) is a major disease of wheat in Kenya. The disease was previously contained by the rpg1, sr31, 24 and 36 genes for resistance that were incorporated in the genotypes of barley and wheat grown in Kenya. In 1999, a new race Ug99 was detected in tritici. The germplasms showed varying levels of resistance to stem rust. At seedling stage, the infection levels ranged from 0 to 2, except in ICARDA-09 and ICARDA-11 that showed infection types 3 and 3,4 respectively. At adult plant stage, genotypes ICARDA-01, Nguzo and Karne were moderately resistant while the rest were susceptible or moderately susceptible. In the field, the new line 1512-5 showed the highest severity of 93% in season 1, with Sabini having the highest severity of 30% in the second season; Nguzo had the lowest disease severity of 16% and 5% in season 1 and 2 respectively. The highest reduction in percent germination (54.1% and 38.3%) was recorded in 1385-13 and ICARDA-10 in season 1and 2 respectively. The highest loss (9.00 %) in protein content was observed in Sabini in season 1 and a loss of 4.0 and 16.3% in zeleny content was noted in season 1 and 2 respectively. From the results in this experiment most of the Kenyan grown cultivars were susceptible to the new race of stem rust. This emphasizes the need for regular monitoring of the stem rust pathogen, in particular isolates in the variable Ug99 lineage, as well as continued resistance breeding. The study has demonstrated the pathogenicity of PgtUg99 to barley despite the fact that it poses a great threat to wheat production in the world
First report of Rice yellow mottle virus on rice in Burundi
International audienceFirst Report of Rice yellow mottle virus on Rice in Burund
Nutrients’ distribution and their impact on Pangani River Basin’s ecosystem – Tanzania
Research Articles published by Taylor & Francis GroupSurface and groundwater from Pangani River Basin (PRB) were sampled in dry and wet seasons,
analysed for dissolved organic and inorganic nutrients (N, P, Si and Urea). There was spatial and
seasonal nutrients’ variability, with enrichment of dissolved inorganic fractions accumulated from
natural and anthropogenic sources. Silicates increased in dry season, whereas nitrate,
ammonium, phosphate and urea increased in wet season; except for phosphate, other nutrients
increased from upstream to the river mouth. High rate of chemical weathering possibly due to
tropical climate and volcanic rocks has caused PRB to have higher concentration of silicates than
average freshwater African Rivers. Contribution of PRB to the coast of Indian Ocean was 2.6, 39.0,
45.2, 67.4 and 5444.8 (mol/km2/yr) for nitrite, phosphate, ammonium, nitrate and silicates,
respectively, which were lower than most of the tropical rivers in the world. Levels of nitrate and
phosphate for most of the stations were higher than recommended levels for aquatic ecosystem
health. Furthermore, observed hypoxia condition in some stations threatens aquatic life. This
study recommends the efficient use of fertilizers to reduce nutrients’ uptake into the lakes and
rivers so as to meet the recommended level for aquatic and human health
Seasonal water chemistry variability in the Pangani River basin, Tanzania
Research Article published by SpringerThe stable isotopes of δ18O, δ2H, and 87Sr/86Sr and
dissolved major ions were used to assess spatial and seasonal
water chemistry variability, chemical weathering, and hydrological
cycle in the Pangani River Basin (PRB), Tanzania.
Water in PRB was NaHCO3 type dominated by carbonate
weathering with moderate total dissolved solids. Major ions
varied greatly, increasing from upstream to downstream. In
some stations, content of fluoride and sodium was higher than
the recommended drinking water standards. Natural and anthropogenic
factors contributed to the lowering rate of
chemical weathering; the rate was lower than most of tropical
rivers. The rate of weathering was higher in Precambrian than
volcanic rocks. 87Sr/86Sr was lower than global average
whereas concentration of strontium was higher than global
average with mean annual flux of 0.13 × 106 mol year−1.
Evaporation and altitude effects have caused enrichment of
δ18O and δ2H in dry season and downstream of the river.
Higher d-excess value than global average suggests that most
of the stations were supplied by recycled moisture. Rainfall and groundwater were the major sources of surface flowing
water in PRB; nevertheless, glacier from Mt. Kilimanjaro has
insignificant contribution to the surface water.We recommend
measures to be taken to reduce the level of fluoride and sodium
before domestic use
In vitro antileishmanial activity and phytochemical analysis of Carissa edulis against Leishmania major
Background: However, there is need to carry out scientific studies in order to confirm the medicinal properties of many plants used traditionally. Carissa edulis Forskk. (Gentiales: Apocynaceae) used by local communities for the treatment of various diseases has showed antiviral, antibacterial and antiprotozoal properties although there are no studies demonstrating its antileishmanial activity. Objective: To investigate in vitro antileishmanial activity of extracts of Carissa edulis on promastigote and amastigote forms of Leishmania major. Methodology: Solvent extraction of the stem parts of C. edulis was performed using water, methanol, petroleum ether, dichloromethane and ethyl acetate. Minimum inhibitory concentration (MIC), anti-amastigote and nitric oxide production assays were carried out to demonstrate antileishmanial activity of C. edulis extracts against the two forms of L. major parasite species: promastigote and amastigote. The extracts were also screened for phytochemical constituents present. Cytotoxicity assay was then done to assess their safe use as herbal medicinal products. Results: The C. edulis petroleum ether extract showed the strongest antileishmanial activity against L. major promastigotes (MIC=625μg/ml) with the water, dichloromethane and ethyl acetate extracts recording the weakest activity (MIC=2500μg/ml). The successive methanol extract reduced the number L. major amastigotes by 88.29% compared to the negative control (RPMI). The water (13.37μM), petroleum ether (12.93μM) and successive methanol extracts (12.82μM) produced nitrite values lower than the standard drugs Pentostam® (14.35μM) and Amphotericin B (14.13μM). Discussion: All C. edulis extracts have potential antileishmanial activity against L. major. Preliminary phytochemical screening of these extracts showed presence of alkaloids, terpenoids, phenols, anthraquinones and saponins. These phytochemicals were previously reported to have antileishmanial activity. Therefore, the plant extracts could offer an opportunity to develop cheaper antileishmanial alternatives to the more expensive pentavalent antimonials. Key words: C. edulis, L. major, promastigote, amastigot
Association between footwear use and neglected tropical diseases: a systematic review and meta-analysis
BACKGROUND
The control of neglected tropical diseases (NTDs) has primarily focused on preventive chemotherapy and case management. Less attention has been placed on the role of ensuring access to adequate water, sanitation, and hygiene and personal preventive measures in reducing exposure to infection. Our aim was to assess whether footwear use was associated with a lower risk of selected NTDs.
METHODOLOGY
We conducted a systematic review and meta-analysis to assess the association between footwear use and infection or disease for those NTDs for which the route of transmission or occurrence may be through the feet. We included Buruli ulcer, cutaneous larva migrans (CLM), leptospirosis, mycetoma, myiasis, podoconiosis, snakebite, tungiasis, and soil-transmitted helminth (STH) infections, particularly hookworm infection and strongyloidiasis. We searched Medline, Embase, Cochrane, Web of Science, CINAHL Plus, and Popline databases, contacted experts, and hand-searched reference lists for eligible studies. The search was conducted in English without language, publication status, or date restrictions up to January 2014. Studies were eligible for inclusion if they reported a measure of the association between footwear use and the risk of each NTD. Publication bias was assessed using funnel plots. Descriptive study characteristics and methodological quality of the included studies were summarized. For each study outcome, both outcome and exposure data were abstracted and crude and adjusted effect estimates presented. Individual and summary odds ratio (OR) estimates and corresponding 95% confidence intervals (CIs) were calculated as a measure of intervention effect, using random effects meta-analyses.
PRINCIPAL FINDINGS
Among the 427 studies screened, 53 met our inclusion criteria. Footwear use was significantly associated with a lower odds of infection of Buruli ulcer (OR=0.15; 95% CI: 0.08-0.29), CLM (OR=0.24; 95% CI: 0.06-0.96), tungiasis (OR=0.42; 95% CI: 0.26-0.70), hookworm infection (OR=0.48; 95% CI: 0.37-0.61), any STH infection (OR=0.57; 95% CI: 0.39-0.84), strongyloidiasis (OR=0.56; 95% CI: 0.38-0.83), and leptospirosis (OR=0.59; 95% CI: 0.37-0.94). No significant association between footwear use and podoconiosis (OR=0.63; 95% CI: 0.38-1.05) was found and no data were available for mycetoma, myiasis, and snakebite. The main limitations were evidence of heterogeneity and poor study quality inherent to the observational studies included.
CONCLUSIONS/SIGNIFICANCE
Our results show that footwear use was associated with a lower odds of several different NTDs. Access to footwear should be prioritized alongside existing NTD interventions to ensure a lasting reduction of multiple NTDs and to accelerate their control and elimination.
PROTOCOL REGISTRATION
PROSPERO International prospective register of systematic reviews CRD42012003338
Interpreting malaria age-prevalence and incidence curves: a simulation study of the effects of different types of heterogeneity
ABSTRACT: BACKGROUND: Individuals in a malaria endemic community differ from one another. Many of these differences, such as heterogeneities in transmission or treatment-seeking behaviour, affect malaria epidemiology. The different kinds of heterogeneity are likely to be correlated. Little is known about their impact on the shape of age-prevalence and incidence curves. In this study, the effects of heterogeneity in transmission, treatment-seeking and risk of co-morbidity were simulated. METHODS: Simple patterns of heterogeneity were incorporated into a comprehensive individual-based model of Plasmodium falciparum malaria epidemiology. The different types of heterogeneity were systematically simulated individually, and in independent and co-varying pairs. The effects on age-curves for parasite prevalence, uncomplicated and severe episodes, direct and indirect mortality and first-line treatments and hospital admissions were examined. RESULTS: Different heterogeneities affected different outcomes with large effects reserved for outcomes which are directly affected by the action of the heterogeneity rather than via feedback on acquired immunity or fever thresholds. Transmission heterogeneity affected the age-curves for all outcomes. The peak parasite prevalence was reduced and all age-incidence curves crossed those of the reference scenario with a lower incidence in younger children and higher in older age-groups. Heterogeneity in the probability of seeking treatment reduced the peak incidence of first-line treatment and hospital admissions. Heterogeneity in co-morbidity risk showed little overall effect, but high and low values cancelled out for outcomes directly affected by its action. Independently varying pairs of heterogeneities produced additive effects. More variable results were produced for co-varying heterogeneities, with striking differences compared to independent pairs for some outcomes which were affected by both heterogeneities individually. CONCLUSIONS: Different kinds of heterogeneity both have different effects and affect different outcomes. Patterns of co-variation are also important. Alongside the absolute levels of different factors affecting age-curves, patterns of heterogeneity should be considered when parameterizing or validating models, interpreting data and inferring from one outcome to anothe
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