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Applicability of bio-adsorbents synthesized from maize/corn plant residues for heavy metals removal from aquatic environments:an insight review
Get PDFThis research article was published by the International Journal of Environmental Quality, 2023The underutilization of agricultural waste products in recent years has resulted in environmental issues owing to improper disposal. As a result, heavy metals removal from aqueous systems utilizing sorbent materials produced from agricultural wastes has received a lot of attention. The current study provides an insightful review of the use of bio-adsorbents synthesized from maize/corn residues to decontaminate various toxicants from wastewater. Although bio-adsorbents made from maize/corn residues have shown to be efficient in the sequestration of heavy metals from wastewater, no study has looked at hybrid bio-adsorbents made from various parts of the maize/corn plant. Moreover, all studies practically investigate the sorption processes using the one-factor design technique, which exceedingly consumes time and is expensive for a significant number of biosorption/adsorption factors. Besides, the majority of the studies used bio-adsorbents produced from maize/corn biomass to remove heavy metals from single sorption systems. Furthermore, very few studies have focussed on heavy metals desorption from the exhausted maize/corn bio-adsorbents following the adsorption process to recycle the spent bio-adsorbents for future usage, which would be more cost-effective. Based on the gaps revealed in this review, it is recommended that further investigations on the usefulness of bio-adsorbents derived from maize/corn biomass in cleansing different water toxicants should be carried out
Analysis of spatial and temporal trend of hydro‑climatic parameters in the Kilombero River Catchment, Tanzania
No full textThis research article was published by Springer Nature Limited in 2023Inadequate knowledge on actual water availability, have raised social-economic conficts that
necessitate proper water management. This requires a better understanding of spatial–temporal
trends of hydro-climatic variables as the main contributor to available water for use by sectors of
economy. The study has analysed the trend of hydro-climatic variables viz. precipitation, temperature,
evapotranspiration and river discharge. One downstream river gauge station was used for discharge
data whereas a total of 9 daily observed and 29 grided satellite stations were used for climate data.
Climate Hazards Group InfraRed Precipitation was used for precipitation data and Observational Reanalysis Hybrid was used for Temperature data. Mann–Kendall Statistical test, Sen’s slope estimator
and ArcMap Inverse Distance Weighted Interpolation functionality were employed for temporal,
magnitude and spatial trend analysis respectively. Results confrmed that, spatially, there are three
main climatic zones in the study area viz. Udzungwa escarpment, Kilombero valley and Mahenge
escarpment. On temporal analysis, with exception of the declining potential evapotranspiration
trend, all other variables are on increase. This is with catchment rates of 2.08 mm/year, 0.05 °C/year,
0.02 °C/year, 498.6 m3
/s/year and − 2.27 mm/year for precipitation, Tmax, Tmin, river discharge and
PET respectively. Furthermore, rainfalls start late by a month (November) while temperatures picks
earlier by September and October for Tmax and Tmin respectively. Water availability matches farming
season. However, it is recommended to improve water resources management practices to limit fow
impairment as expansions in sectors of economy are expected. Furthermore, landuse change analysis
is recommended to ascertain actual trend and hence future water uptake
Building Resilient Crop Production Systems for Drought-Prone Areas—A Case for Bambara Groundnut (Vigna subterranea L. Verdc) and Groundnut (Arachis hypogaea L.)
Get PDFThis research article was published by MDPI, in 2023Drought is a major crop production constraint worldwide. Some legume crops are known for their ability to resist water deficit stress. This study evaluated the responses of bambara groundnut (Vigna subterranea (L.) Verdc) and groundnut (Arachis hypogaea (L.) to soil water deficit stress. The experiment was set as a split-plot randomized complete block design. Three bambara groundnut landraces: viz DodR, NALBAM 4 and S19-3, and one groundnut variety, MNANJE, were assigned to subplots with three water regimes assigned to main plots (regime one: irrigated throughout the growing period, regime two: water deficit stress was imposed at the start of flowering to the end of first flush flowering, regime three: water was withheld during the pod development). Water deficit stress increased proline content by 123% in stressed plots. The highest (174%) and lowest (89%) proline increases were evident in the genotypes MNANJE and NALBAM 4, respectively. Water deficit decreased stomatal conductance, transpiration rate and photosynthetic rate, with MNANJE and S19-3 showing the smallest percentage decrease in most of the traits. This suggests that the two genotypes are drought resistant. The variations observed among landraces could be exploited to breed resilient varieties for cultivation in drought-prone areas, ultimately improving food security
Performance of Tuberculosis Molecular Bacterial Load Assay Compared to Alere TB-LAM in Urine of Pulmonary Tuberculosis Patients with HIV Co-Infections
Get PDFThis research article was published by MDPI in 2023Alternative tools are needed to improve the detection of M. tuberculosis (M. tb) in HIV co-infections. We evaluated the utility of Tuberculosis Molecular Bacterial Load Assay (TB-MBLA) compared to lipoarabinomannan (LAM) to detect M. tb in urine. Sputum Xpert MTB/RIF-positive patients were consented to provide urine at baseline, weeks 2, 8, 16, and 24 of treatment for TB-MBLA, culture, and LAM. Results were compared with sputum cultures and microscopy. Initial M. tb. H37Rv spiking experiments were performed to validate the tests. A total of 63 urine samples from 47 patients were analyzed. The median age (IQR) was 38 (30–41) years; 25 (53.2%) were male, 3 (6.5%) had urine for all visits, 45 (95.7%) were HIV positive, of whom 18 (40%) had CD4 cell counts below 200 cells/µL, and 33 (73.3%) were on ART at enrollment. Overall urine LAM positivity was 14.3% compared to 4.8% with TB-MBLA. Culture and microscopy of their sputum counterparts were positive in 20.6% and 12.7% of patients, respectively. Of the three patients with urine and sputum at baseline, one (33.33%) had urine TB-MBLA and LAM positive compared to 100% with sputum MGIT culture positive. Spearman’s rank correction coefficient (r) between TB-MBLA and MGIT was −0.85 and 0.89 with a solid culture, p > 0.05. TB-MBLA has the promising potential to improve M. tb detection in urine of HIV-co-infected patients and complement current TB diagnostics
Understanding farmer knowledge and site factors in relation to soil-borne pests and pathogens to support agroecological intensification of smallholder bean production systems
Get PDFThis research article was published by Frontiers in Sustainable Food Systems in 2023Introduction: Pests and diseases limit common bean (Phaseolus vulgaris) production in intensifying smallholder farming systems of sub-Saharan Africa. Soil-borne pests and diseases (SPD) are particularly challenging for farmers to distinguish and manage in cropping systems that vary in terms of soils, farmer knowledge, and management factors. Few studies have examined soil drivers of SPD in smallholder systems, integrated with farmers' perceptions and management practices.
Methods: In Kilimanjaro, Tanzania, we assessed farmer knowledge and SPD management for common bean alongside soil type and soil quality. Focus group discussions and field survey findings including farmer observations and soil nutrient balances were integrated with soil analyses of farmers' fields. Multiple correspondence analysis (MCA) and principal component analysis (PCA) assessed relationships among farmer demographics, pests and diseases, soil characteristics, and management practices.
Results and discussion: Surveys revealed that 100% of farmers knew of the bean foliage beetle (Ootheca bennigseni) but few recognized the soilborne pest Ophiomyia spp. or bean fly despite it being more destructive. About a third of farmers knew of root rot diseases caused by Pythium spp. and Fusarium spp. Synthetic pesticides were used by 72% of farmers to control pests, while about half that (37%) used pesticidal plants, particularly Tephrosia vogelii extracts sprayed on foliage. Regarding SPD, 90% of farmers reported that their management practices were ineffective. Meanwhile, synthetic fertilizers were used by nearly all farmers in beans intercropped with maize (Zea mays), whilst very few farmers used manure or compost. Soil available phosphorus was lowbut showed a balance between inputs and outputs regardless of whether fields were owned. Field nitrogen balances were more negative when fields were owned by farmers. An MCA showed that older farmers employed a greater number of pest control practices. The PCA showed that field variability was dominated by soil organic matter, elevation, and soil pH. Higher organic matter levels were also associated with less stunting and wilting of beans observed by farmers. Our results suggest that research and farmer learning about SPD ecology are key gaps, alongside recycling of organic residues to soils. Cost-effective and sustainable practices to manage bean SPDs for smallholders are also needed
Development of Railway Information System to Improve Railway Data Aggregation and Analysis in Tanzania
Get PDFThis research article was published by Hindawi in 2023For more than three decades, railway transportation in Tanzania has been in an on-and-off state even though a railway network exists. This is due to damaged tracks, a lack of proper management, and railway operational information. Recently, the Tanzanian government made efforts to revive railway transportation by reopening a few train routes and constructing a new and improved railway network. Even with revived operations, the digitalization process of railway data is still at a low pace as most data is populated in excel sheets for analysis; the major source of data being paper-based. With the use of a mixed research method, this paper provides an information system in the form of mobile and web applications, which provide a platform for populating railway data through the web application accessible to the railway corporation and disseminating railway information to the public through the mobile application. With these platforms, data aggregation and analysis have been made easier and more understandable than the use of excel sheets alone. The results show great possibilities for increased use of digital techniques such as web mapping, which contribute to higher data accuracy and better visualization of railway information that can be disseminated to the public
Experimental Investigation of Soapstone and Granite Rocks as Energy-Storage Materials for Concentrated Solar Power Generation and Solar Drying Technology
Get PDFThis research articles was published in Journals American Chemical Society , 2023The intermittence of solar energy resource in concentrated solar power (CSP) generation and solar drying applications can be mitigated by employing thermal energy storage materials. Natural rocks are well recommended thermal energy storage materials as they are efficient for CSP generation. This study explores the potential of soapstone rock and also the influence of the sites’ geo-tectonic setting to soapstone and granite rocks as thermal energy storage materials. Experimental characterization was done to investigate the thermo-chemical properties (thermal stability (TGA), crystalline phases (XRD), petrographic imaging and chemical composition (XRF), and high temperature test); the thermo-physical properties (density, porosity, specific and thermal capacity (DSC), thermal diffusivity, and conductivities (LFA)); and the thermo-mechanical properties (Young’s modulus) of the rocks. Consequently, the rock with the most desired properties for thermal energy storage was the soapstone rock from the Craton geo-tectonic setting and it had a Young’s modulus of 135 GPa at room temperature. At solar drying and CSP temperatures it had thermal capacities of 3.28 MJ/(m3·K) and 4.65 MJ/(m3·K); densities of 2.785 g/cm3 and 2.77 g/cm3; and conductivities of 2.56 W/(m·K) and 2.43 W/(m·K) respectively, and had weight loss of 0.75% at 900 °C. At high temperatures, only granite from Craton had visible cracks while the other 3 rocks did not show visible signs of fracture. Conclusively, soapstone and granite from Craton in the Dodoma region and Usagaran in the Iringa geo-tectonic settings exhibit significant differences in most thermo-properties
The mtego® trap: a potential tool for monitoring and control of malaria and arbovirus vectors
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 TechnologyOdour-baited traps are valuable for vector surveillance and control; however, they often exhibit
varying recapture rates among mosquito species due to the limited range of host cues they provide.
Therefore, it is crucial to develop more effective traps capable of capturing a variety of mosquito
species. One potential alternative is the MTego trap, which incorporates thermal stimuli as
additional cues. This study aimed to evaluate the efficacy of the MTego trap for sampling different
mosquito species in a semi-field system. To conduct the experiments, fully balanced Latin square
design experiments were conducted in semi-field chambers using laboratory-reared female
Anopheles gambiae, Anopheles funestus, Anopheles arabiensis, Culex quinquefasciatus, and
Aedes aegypti mosquitoes. Fifty mosquitoes of each species were released in each chamber for 16
days. The evaluated traps included the MTego trap baited with PM6 (MT-PM6), the MTego trap
baited with BG-Lure (MT-BGL), and the BGP trap baited with BG-Lure (BGP-BGL). In addition,
the performance of the traps was compared to the human landing catch (HLC). The MTego traps
(MT-PM6 and MT-BGL) captured a similar proportion of Anopheles gambiae and Anopheles
funestus, and Aedes aegypti as the BGP-BGL. However, the traps did not match the performance
of HLC against all mosquito species. The study underscores the promising application of the
MTego trap as a monitoring and control tool for malaria and arbovirus vectors
Fish Diversity in Relation to Littoral Habitats in Three Basins of Lake Kivu (East Africa)
Get PDFThis research article was published in Diversity Journal, Volume 15, 2023.In total, 28 of the 29 fish species reported from the Lake Kivu basin occur in the littoral zone of the lake, but information about their structure, occurrence, and the habitats affecting their distribution is largely lacking. The lake’s inshore area is poorly heterogenous, with rock and macrophyte habitats representing the major habitats. The lack of heterogeneity in the habitats is probably an important factor influencing species richness, abundance, and the association between the species and habitats. We evaluated the fish diversity, abundance, and habitat parameters across 14 sites representing the major habitats of the lake, using data collected between April 2018 and October 2019. We calculated Hull and Jaccard indices and applied uni- and multivariate statistical approaches to the collected data. We identified 18 fish species in the lake. In the north, 17 species were found, with high abundance in rocky sites but low abundance in sandy habitats. In the south, 15 species were reported. We identified 12 species in the Ishungu Basin where the site with rock substrate had high abundance and 13 species in the Bukavu Basin with weak species richness and low abundance across degraded sites. Lamprichthys tanganicanus, a non-native species, was abundant in rocky (north) and macrophyte sites (south). Sand, rock, conductivity, depth, dissolved oxygen, and water transparency were significant parameters that could explain the fish distribution in the north while dissolved oxygen, vegetation cover, depth, and conductivity were significant in the south. A monitoring programme of the fish fauna in Lake Kivu is needed
Sensor-Based River Monitoring System: A Case for Kikuletwa River Floods in Tanzania
Get PDFA research was submitted to computer science and mathematics volume 2, 2023Reliable and accurate flood prediction is a challenging task in poorly gauged basins due 1 to data scarcity. Data is an essential component of any AI/ML model today, and the performance 2 of such models hugely depends on the availability of sufficient amount of trusted, representative 3 data. However, unlike a few well-studied rivers, most of the rivers in developing countries are still 4 insufficiently monitored, which significantly hinges the design and development of advanced flood 5 prediction models and early warning systems. This paper presents a multi-modal, sensor-based and 6near-real time river monitoring system to produce a mul ti-feature data set for the Kikuletwa river in 7 Northern Tanzania, an area that heavily suffers from frequent floods. Our deployed system, which 8 gather information about river depth levels and weather at several locations, aims at widening the 9
ground truth of the river characteristics and eventually improve the accuracy of flood predictions. We 10 provide details on the monitoring system used to gather the data as well as report on the methodology 11 and the nature of the data. Finally, we present the relevance of the data set in the context of flood 12 prediction, discussing the most suitable AI/ML-based forecasting approaches, while also highlighting 13 some applications of the data set beyond flood warning systems