East African Journal Of Science, Technology and Innovation
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Characterization of Provitamin A Status and Distribution in Commercial Grown Maize Varieties in Tanzania
Get PDFProvitamin A carotenoids are important as precursors for vitamin A, essential for stronger immune system and eyesight. Consumption of a plant-based diet rich in provitamin A such as provitamin A maize is an easy and affordable source of vitamin A. The majority of the commercially grown maize varieties in Tanzania are white whose provitamin A status is uncertain and undocumented. The existing current information suggests that white maize varieties have low provitamin A, an active form of vitamin A, thus putting maize consumers at risk of vitamin A deficiency (VAD). Characterization of provitamin A status in commercial maize varieties grown and consumed in Tanzania is important to provide baseline information required for vitamin A rich-maize improvement programs. Therefore, this study was conducted to map the status of provitamin A in commercial maize varieties to accrue the information needed to improve maize nutrition quality toward controlling VAD in the country. The study involved 14 maize varieties including commercial yellow and white pigmented maize from 3 regions of Tanzania. From maize samples, carotenoid extraction was conducted based on a protocol adapted from Kurilich and Juvik (1999). The concentration of beta carotene (BC), beta-cryptoxanthin (BCX), alpha-carotene (AC) were determined by an ultraviolet spectrophotometer and provitamin A computed for the individual carotenoids components. The study found that the concentration of provitamin A and associated carotenoids significantly differed (p<0.001) among varieties studied. The mean concentration (in μg/g) for provitamin A and its components in range as provitamin A (2.64-6.50), BC (1.91-4.66), BCX (0.649-1.21), and AC (0.819-1.46). The concentrations of provitamin A in the studied maize varieties were below the recommended levels (15 μg/g). The low concentrations of provitamin A among commercial maize varieties signify th
Assessing community perceptions and response to climate change in nyando catchment using geospatial technology
Get PDFThe world is experiencing climate crisis that is threatening lives. Those in low lands are displaced by floods loosing possessions and food crops; while those in hilly areas experience land degradation and vegetation loss leading to poverty. Monitoring such occurrence through time is inevitable as it enables governments to make critical decisions for environmental conservation, enhanced resilience and minimize risks of food insecurity. This study explored the use of geospatial technology to investigate climate risk indicators within Nyando catchment. Geospatial technology provides a platform to monitor occurrences of extreme weather conditions, facilitates the understanding of end to end temporal changes of the environment and provides an environment for modelling future scenarios. We derived indicators of climate change within Nyando catchment over the period 2013 to 2021 and inferred their impact on livelihoods. We collected data on rainfall, vegetation cover and land use from Landsat 8 30m satellite images and in situ data using the Mobile mapper global positioning system (GPS) within Nyando catchment. We overlaid these data, characterized them and performed change detection using Erdas Imagine software. Results showed 9.9% reduction in forest cover, 54.1% sedimentation of water areas, 3.9% loss of agricultural land and 2.5% increase in built up areas. The main land use in Nyando catchment is agriculture followed with settlement. We inferred that loss of forest cover is the reason for sedimentation of the water areas, subjecting lowlands to flooding. Moreover, conversion of forest land to agricultural land and settlement were fund to be the main drivers for climate crisis. Indeed agro-ecological approaches to farming will increase forest area while maximizing on vertical farming for increased productivity to meet the ever growing demand for food. We recommend adoption of geospatial technology in monitoring of the landscape for informed decision making to avert risks of climate change
Socio-Economic Factors Affecting Water Use in Lower Thiba Sub-Catchment, Kirinyaga County, Kenya
Get PDFHuman related activities affect how water is used. However, there is limited information on the effect of socio-economic factors on water use. This study was to establish the socio-economic factors that affect water resource use in Lower Thiba Sub-Catchment using a descriptive survey design. Qualitative as well as quantitative data was collected from 361 households and 5 focus group discussions (n=366) across the Sub-catchment. The sub-catchment was sub-divided into three zones namely; upper zone, middle zone and lower zone, from where each zone, 120 respondents were randomly sampled and issued with a questionnaire. Data was analysed with the help of Statistical Package for Social Sciences (SPSS) at a statistical significance of 5% probability level. Data was then presented using descriptive statistics such as tables, graphs and test for significance was done using Chi-square. The results showed that men were more likely to do irrigation farming than women, with 81%, as compared to their female counterparts who had 68%. Most of the respondents (82%) earned between Kshs. 10,000 (87) from different occupations; however, 4% of respondents, all of who were farmers earned over kshs 70,000(609$) a month, compared to other types of occupation, indicating it as the main economic activity in the area. The results showed that 57.9% of respondents who had tertiary education preferred formal employment over farming with only 9.9% of them choosing to be farmers. The results also showed 75% of the respondents who owned land were male, with only 25% of the female respondents owning land. Further, respondents in formal employment had a higher ownership (83.9%) of water harvesting facilities compared to those doing irrigation farming at 73%. The results indicate that the community socioeconomic factors within the LTS should be considered by policy makers, as they clearly affect water use within the sub-catchment
Effect of precipitation on abundance and molecular diversity of potential vectors for Rift Valley fever virus in Nyandarua County, Kenya
Get PDFRift Valley fever (RVF) is a mosquito-borne viral zoonotic disease that causes significant economic and public health impacts in Kenya. Currently, there is inadequate information on rainfall patterns and mosquito diversity, including the dominant species in Nyandarua. Therefore, this study aimed to determine the rainfall patterns, relative abundance, and diversity of mosquito species that can transmit the RVF virus (RVFV) in Nyandarua. Mosquitoes were purposively collected from all the homesteads with suspect RVF cases in 10 villages using the CDC light trap during the dry (January 2021), long (July 2020), and short (November 2021) rainy seasons. Rainfall data was derived from the Climate-SERV satellite database. The mosquitoes were identified morphologically using a dissecting microscope and their identities, as well as genetic diversity, were determined using sequencing and phylogenetic analysis of the CO1 gene. A total of 97, 328, and 366 mosquitoes were trapped during the dry, long and short rainy seasons, respectively. There was variation in the average daily rainfall between 2015 and 2021 during the three seasons. Of the mosquitoes trapped, 71 (9%) were males while 720 (91%) were females with 26 (4%) mosquitoes being blood-fed. During the three seasons, various species of mosquitoes including Culex pipiens (58%), Culex theileri (16%), Culex vansomereni (3%), Culex rima (2%), and Culex perexiguus (3%) were identified (Simpson index = 0.4). Culex pipiens was the most dominant species in this ecosystem (Shannon index = 1.2). We conclude that the anomalous variations in rainfall patterns may be correlated with the emergence of diverse species of mosquitoes that have the potential to transmit RVFV to animals in Nyandarua
An An inverse artificial neural network algorithm for retrieval of sunshine hours from ground-based global solar irradiation measurements
No full textAvailability of meteorological parameter values is important in applications that require solar irradiation. Meteorological parameters such as sunshine hours are best provided by measuring equipment mainly stationed at weather stations. The cost of purchasing the measuring equipment, and setting up and maintaining weather stations is enormous and cannot be easily afforded by many developing countries like Uganda. Furthermore, in Uganda, we have some weather stations which have been measuring global horizontal solar irradiation for quite some time but lacked sunshine duration sensors, and at some others, the sunshine measuring equipment malfunctioned. In this work we present an inverse artificial neural network algorithm that predicts sunshine hours based on horizontal global solar irradiation, the algorithm caters to cases where global horizontal solar irradiation is present but sunshine hour measuring equipment is missing or malfunctioned. A radial basis function neural network (RBF-NN) was trained for forward computation of global horizontal solar irradiation from sunshine hour values. The inverse modelling algorithm employs multidimensional unconstrained non-linear optimization to retrieve sunshine hours. The correlation coefficient (r) between the measured sunshine hour values and those predicted by the inverse artificial neural network algorithm was found to be 0.924. The average value of the ratios of the inverse artificial neural network algorithm computed values to the sunshine duration sensor measurements was 1.043. The algorithm predicted sunshine hour values with a mean bias and relative root mean square error of 0.043 and 0.394, respectively. The algorithm developed provides an affordable, fast and reliable method for determining sunshine hour values based on global horizontal solar irradiation. However, sunshine hour values prediction for low values of global horizontal solar irradiation was less precise, and this could be attributed to high levels of cloudiness. It is recommended that an inverse algorithm that retrieves sunshine hours under cloudy conditions be constructe
Nuclear polaritons: Mössbauer source and resonant absorber investigated using the coherent paths model
Get PDFResonant nuclei of a Mössbauer absorber, interacting with the recoil free emitted radiation from a Mössbauer source, can re-emit it without recoil, leading to nuclear-resonant scattering. During the nuclear resonance scattering in the Mössbauer absorber, intermediate states which are combinations of nuclear excited states and electromagnetic radiation (gamma radiation) states are produced. These states are called nuclear polaritons. In this paper, a description of the nuclear polariton inside a Mössbauer absorber is presented by adapting the quantum model previously developed by Heitler, Harris and Hoy, called “the coherent paths model”. This model allows the calculation of all spatial and temporal properties of the nuclear excited states as well as the electromagnetic radiation present inside a resonant absorber. The thickness of the absorber is modeled using a parameter N. The nuclear polariton results then from the magnetic dipole interaction between the quantified electromagnetic radiation and the resonant nuclei of the absorber. It is an entangled state, composed by the excitation of the nuclei (exciton) and the electromagnetic field. The evolution of the nuclear exciton, both as a function of time and as a function of the position of the resonant nuclei in the absorber, is studied. This constitutes the nuclear part of the polariton. The field associated with the gamma radiation inside the absorber is studied also as a function of position in the absorber and as a function of time, which is the field part of the polariton. Using the purely quantum coherent paths model, we find out that the energy of the polariton inside the absorber oscillates between the nuclear excitation and the field of electromagnetic radiation. Nuclear polariton study is then a potential method for probing matter at the subatomic scale
Barriers and Enablers of adoption of Rain Water Harvesting Technologies at County Levels: A Case of Matungulu Sub-County, Machakos County Kenya
Get PDFRainwater harvesting technology is among the oldest methods of fetching water among households. The demand for water use has grown globally outpacing population growth, and increasingly, many regions are currently reaching levels which water services are unsustainable, especially in Arid and Semi-Arid Lands (ASAL) regions. Inadequate water for domestic and agricultural use has had negative impacts on households in ASAL areas. There has been however introduction of rainwater harvesting technologies that seeks to solve the effects of water scarcity in these areas. Adoption of these technologies depend on factors that hinder/encourage households to adopt them. Matungulu Sub-County is such area that requires adoption of these technologies. Focus group discussions, interviews with key informants, and structured questionnaires were used to collect data. Descriptive and inferential statistics were used in data analysis. This involved calculation of arithmetic mean, standard deviation, percentages, frequencies and Analysis of Variance. The study identified 5 rainwater harvesting methods; Surface rainwater harvesting, Rooftop rainwater harvesting, Catchments, First flush and Filter. Findings indicated that overall, a composite mean of 4.04 and a standard deviation of 0.699 of the respondents agreed that incentives from the county government significantly promoted water-harvesting technologies. This was confirmed by a positively strong and significant correlation between integration of Rainwater Harvesting Technologies in the county development agenda. Results of this survey indicate that mostly household heads finance rainwater technologies and County Government initiatives have not been adequately felt. The study findings indicate that the major barriers to adopting rainwater technologies are costs and a lack of expertise on the adoption of these technologies. To ensure the sustainability of rainwater harvesting technologies, the study recommends the development of clear monitoring systems on water collection in the County. Additionally, there is a need to strengthen funding and sensitization on the best technologies to enhance water harvesting
Ethnobotanical study of pesticidal plants against human harmful insects in Central Burundi
Get PDFHuman harmful insects include mosquitoes, lice, fleas, flea-biters, bedbugs, flies and fire ants. Developing countries, such as Burundi; are challenged in the access of chemical products to control these insects. The present study aims to control human harmful insects with pesticidal plants based on ethnobotanical knowledge of Burundians. A survey on pesticidal plants was carried out using a questionnaire on 250 participants in Gitega province, Central Burundi. The consensus index (CIs) was used to analyse the credibility of the information collected. Seventy five percent of participants recognized at least one pesticidal plant. The present study reveals 69 plant species divided into 35 families. The Asteraceae (8 species) and Euphorbiaceae (6 species) families were the most represented. Of all the plant species recorded, the most exploited part is the leaf (47% of species) and 50% of species are used without prior preparation, while 22% are roasted before use or administration. The local application is most used (for 46% of species). The most cited species are Tetradenia urticifolia (ICs: 0.60), Euphorbia tirucalli L (ICs: 0.10) and Tagetes minuta L (ICs: 0.06) repelling fire ants, Solanum incanum (ICs: 0.60) and Gymnanthemum amygdalinum (ICs: 0.12) treating the flea-bites. The present study showed a large number of pesticidal plants, some of them having a considerable potential in the control and treatment of these insects and their bites. The preferred use of the leaves leads to a promising valorisation with less impact on sustainable conservation of the reported plant species. The present study revealed the importance of pesticidal plants knowledge with an emphasis on plants against flea-bites and fire ants (31 and 23 species respectively). The results suggest that there is need for phytochemical studies aimed at the production of effective and affordable plant-based pesticides
Performance of African catfish Clarias gariepinus larvae fed on formulated diets containing Spirulina platensis and Eisenia fetida
Get PDFProfitable aquaculture depends on quality seed and fish feed used. The need to use significant amount of aquatic resource proteins in aquafeed presents economic and environmental challenges. Therefore, it is necessary to develop sustainable, cheaper, renewable and ecofriendly protein alternatives to replace aquatic resource proteins, hoping for their eventual elimination from larviculture. The current study evaluated Spirulina platensis and Eisenia fetida as dietary protein sources for Clarias gariepinus larvae (0.002g±0.04). Hundred percent Caridina nilotica in the control diet was partially replaced by either Spirulina platensis or Eisenia fetida at 25%, 50% and 75% to formulate six approximately isonitrogenous and isocaloric Clarias gariepinus larval diets (T1, 25%S. platensis +75%C. nilotica; T2, 50%S. platensis + 50%C. nilotica; T3,75%S. platensis +25%C. nilotica; T4,25%E. fetida + 75%C. nilotica; T5,50%E. fetida +50%C. nilotica; T6 ,75%E. fetida +25%C. nilotica). Diets were randomly assigned to 21 glass aquaria in triplicate. Twenty-five larvae per liter were randomly distributed into each aquarium, 48 hours after hatching. The larvae were fed at 20% body weight decreasing to 10% by fourth week of the experimental period, five times a day for eight weeks. Growth performance, nutrient utilization and survival response were evaluated in controlled culture conditions. Each diet formulation cost was also estimated. A combination of 50% Eisenia fetida and 50% Caridina nilotica performed significantly (p<0.05) better in growth, nutrient utilization and survival at a relatively low formulation cost. Possibly because of higher levels of methionine, lysine, isoleucine, leucine, valine, arginine, glutamic and phenylamine which are responsible for enhanced growth and survival. However, these parameters reduced in larvae fed on 50% Spirulina platensis and 50% Caridina nilotica due to higher crude fiber. Caridina nilotica can be replaced with either Eisenia fetida up to 75% or 25% of Spirulina platensis without negative effect on growth, nutrient utilization and survival
Indigenous versus exotic tree species used in silviculture and agroforestry: An overview from Burundi Seed Centre data
Get PDFIn Burundi, natural ecosystems are found mainly in protected areas and indigenous species seem to be scarce in silvicultural and agroforestry programs. The indisputable enthusiasm of the population to use Eucalyptus has already completely transformed the Burundian landscape. The present study aims at analyzing the extent of the exotic species use versus indigenous by different stakeholders, among them the Government of Burundi. Sales statistics (2012-2021) from the Burundian Office for the Protection of the Environment seed bank were analyzed. The study reveals that out of 23 species, seeds of only three indigenous tree species are sold. The latter corresponds to 27% of the total seed weight, representing only 0.11% of the total seed number. Eucalyptus div. sp. are the most dedicated to silvicultural programs with 99.63% of total seeds; no indigenous tree species is known for silviculture in Burundi. Concerning agroferestry, indigenous species are represented by Maesopsis emenii, Markhamia lutea and Polycias fulva totaling 29.03 % of total seed weight, equivalent to only 1.17 % of the total seed number. The most used species are exotic, namely Grevillea robusta, Calliandra calothyrsus and Cedrella serrulata, representing 57%, 25.43% and 11.36% of total seed number respectively. Likewise, the Government programs as well as other stakeholders are choosing seed species in the same way. This study showed the exclusive use of exotic species in silvicultural where Eucalyptus div.sp. have won over foresters and the general population due to their rapid growth, high productivity and regeneration regardless soil quality. The present study confirms the quasi-exclusive use of exotic tree species in silvicultural and agroforestry programs by different actors. Our findings suggest the need to seek for alternative indigenous tree species to promote. Relevant policies should be revised and implemented accordingly for the soil conservation and ecosystem restoration as well as reforestation