Research Articles

Permanent URI for this collection

https://dir.muni.ac.ug/handle/20.500.12260/320

Browse

Now showing 1 - 20 of 86

A Comparative study of photon radiation-shielding properties of different glass types for use in health facilities
(University of Warwick and Monash University, 2024-09-11) Nyangoma, Judith; Oryema, Bosco
The usage of X-ray generating devices and gamma-ray sources such as 60Co and 137Cs for medical diagnostic and therapeutic applications has increased globally. However, exposure to radiation from these sources can cause detrimental effects on biological tissues. Thus, to optimise radiation safety, effective radiation shields are required. This study used the photon shielding and dosimetry (PSD) software to simulate and compare the photon shielding properties of phosphate, bismuthate, tellurite, silicate and borate glass for use in medical facilities. The parameters investigated included mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value layer (HVL), mean-free path (MFP), and effective atomic number (Zeff). The results showed that bismuthate glass had the highest MAC and LAC values followed by tellurite, silicate, phosphate and borate glass respectively. It was also found that bismuthate glass had the lowest HVL and MFP values followed by tellurite, silicate, phosphate and borate glass. Since materials with high MAC and LAC and low HVL and MFP are associated with higher photon stoppage powers, bismuthate glass are better photon shielding materials compared to the rest of the glass examined in this study. Conversely, borate glass presented the least shielding potential compared to phosphate, silicate and tellurite glass.
Agronomic suitability for oil palm growing in Uganda
(Journal of Agricultural Science, 2024-03-15) Ddamulira, Gabriel; Asiimwe, Alex; Masika, Fred; Amugoli, Moses; Ddumba, Gerald; Maphosa, Mcebisi
The ever-increasing demand for vegetable oils with its products in Uganda, calls for new areas to be put under oil palm cultivation. A study was conducted to investigate the agronomic suitability of oil palm cultivation in six areas located within a 30 km radius off-shore, on the island and more than 30 km radius off-shore on the mainland. The experiment was superimposed on 45 × 45 m plots in oil palm adaptive trial plantations established in 2008 in Bugiri, Mayuge, Buvuma, Mukono, Kibaale and Masaka districts. The experiment was laid out in a randomized complete block design with three replications. Data on number of oil palm bunches, bunch weight and yield was collected while climatic data (rainfall, temperature, relative humidity and radiation) was acquired from meteorological stations near the experimental locations. Rainfall data analyzed and dry season duration suggested that Mayuge, Masaka, Mukono, Buvuma and Kibaale were moderately favorable for oil palm growing, while temperature and radiation data indicated that all study locations were suitable for oil palm growing. Furthermore, based on relative humidity, Buvuma, Mayuge and Bugiri were suitable for oil palm cultivation but Kibaale, Masaka and Mukono were moderately suitable. Oil palm yield varied significantly (P < 0.05) across locations. The yield was much greater in Mukono (17.7 t/ha/yr) followed by Buvuma (13.8 t/ha/yr) and Kibaale (12.9 t/ha/yr) then Mayuge (10.7 t/ha/yr), Bugiri (10.2 t/ha/yr), and Masaka (10.3 t/ha/yr). The significantly high yield of oil palm observed in Mukono was attributed to the high rainfall received in this location. Based on research findings, Mukono, Masaka, Bugiri, Buvuma, Kibaale and areas within the 30 km radius of Lake Victoria are agronomically suitable for oil palm cultivation.
An ethnobotanical survey of plant species used for medicinal purposes in Amuru district, northern Uganda
(Ilia State University, 2024-09-12) Gum, Bornfree; Opoke, Robert; Akwongo, Betty; Oloya, Benson; Omony, John Bosco; Opiro, Robert; Andama, Morgan; Anywar, Godwin; Malinga, Geoffrey Maxwell
Background: Medicinal plants provide health care to rural communities that have limited access to modern medicine in Uganda. Thus, documenting medicinal plants is important for their sustainable utilisation and conservation of medicinal plants and associated indigenous knowledge. Methods: A cross-sectional ethnobotanical survey was conducted in August 2021 to assess the knowledge and use of medicinal plants in Lamogi Sub-County, Amuru district. We randomly sampled and interviewed 334 household heads using semi-structured questionnaires. Data was analysed using descriptive statistics, familiarity index (FI), fidelity level (FL) and informant consensus factor (ICF). Results: Most of the respondents (90%) had knowledge of medicinal plants used for treating ailments in their community (high ICF values above 0.9). Plant with the highest FI value was Gymnanthemum amygdalinum (Delile) Sch.Bip. indicating its wide use in the community. Chi-square tests showed significant associations between the knowledge of medicinal plants and education level, occupation, age, marital status and monthly income of respondents (p < 0.05). Forty-nine medicinal plants from 30 families were documented, with Fabaceae and Asteraceae having the most species. Leaves were the most frequently used plant parts (65.4%), followed by roots (13.6%). Herbal remedies were mostly prepared by crushing and smearing on the body, infusion, decoction and administered orally. Conclusion: The people of Amuru district have rich indigenous knowledge of diverse medicinal plants used for treating ailments. Most medicinal plants are harvested from the wild, threatening their survival and this requires putting in place practical conservation measures.
Antecedents of the theory of planned behaviour as correlates of math anxiety among students in rural Secondary Schools in Western Uganda.
(European Journal of Education Studies, 2020) Batiibwe, Marjorie Sarah Kabuye; Mwebesa, Edson; Tengi, Jacob
Mathematical abilities have been linked to positive outcomes and well-being in adults, although secondary school students in Western Uganda still exhibit math anxiety. Thus, the purpose of the study was to investigate the correlation between the antecedents of the theory of planned behavior (TPB) and math anxiety among students in rural secondary schools in Western Uganda, Ntungamo District, Ruhaama County. Using a quantitative approach, data were collected from a random sample of 578 students using a self-administered questionnaire. Data at the bivariate and multivariate levels were analyzed using Pearson’s Linear Correlation Coefficient and multiple regression analysis respectively. Considering the three antecedents of TPB namely perceived behavioral control, attitude and subjective norms, the study at the bivariate level found that all the three antecedents of TPB positively significantly correlated with math anxiety, thus supporting all the three study hypotheses. At the multivariate level, while all the three TPB antecedents correlated with math anxiety, the correlation between attitude and math anxiety was not statistically significant. Further, subjective norms were the strongest predictor of math anxiety in this particular context. The implication is that interventions with parental views and perceived usefulness of mathematics among students should be dealt with in order to lower the levels of math anxiety among students in rural secondary schools in Western Uganda.
Antimycobacterial Activity of the Extract and Isolated Compounds From the Stem Bark of Zanthoxylum leprieurii Guill. and Perr.
(SAGE Publications, 2021-08-24) Oloya, Benson; Namukobe, Jane; Heydenreich, Matthias; Ssengooba, Willy; Schmidt, Bernd; Byamukama, Robert
Zanthoxylum leprieurii Guill. and Perr. (Rutaceae) stem bark is used locally in Uganda for treating tuberculosis (TB) and cough-related infections. Lupeol (1), sesamin (2), trans-fagaramide (3), arnottianamide (4), (S)-marmesinin (5), and hesperidin (6) were isolated from the chloroform/methanol (1:1) extract of Z. leprieurii stem bark. Their structures were elucidated using spectroscopic techniques and by comparison with literature data. Furthermore, the extract and isolated compounds were subjected to antimycobacterial activity. The extract exhibited moderate activity against the susceptible (H37Rv) TB strain, but weak activity against the multidrug resistant (MDR)-TB strain with minimum inhibitory concentrations (MICs) of 586.0 and 1172.0 μg/mL, respectively. Compound 3 (trans-fagaramide) showed significant antimycobacterial activity against the susceptible (H37Rv) TB strain (MIC 6 μg/mL), but moderate activity against the MDR-TB strain (MIC 12.2 μg/mL). Compounds 2, 5, 6, and 1 showed moderate activities against the susceptible (H37Rv) strain (MIC 12.2-98.0 μg/mL) and moderate to weak activities against theMDR-TB strain (MIC 24.4-195.0 μg/mL). This study reports for the first time the isolation of compounds 1 to 6 from the stem bark of Z leprieurii. trans-Fagaramide (3) may present a vital template in pursuit of novel and highly effective TB drugs.
Apparent density, trypanosome infection rates and host preference of tsetse flies in the sleeping sickness endemic focus of Northwestern Uganda.
(Springer Nature, 2021-11-29) Opiro, Robert; Opoke, Robert; Angwech, Harriet; Nakafu, Esther; Oloya, Francis A; Openy, Geoffrey; Njahira, Moses; Macharia, Mercy; Echodu, Richard; Malinga, Geoffrey M.; Opiyo, Elizabeth A.
African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies. We deployed 109 biconical traps in 10 villages in two districts of northwestern Uganda to obtain information on the apparent density, trypanosome infection status and blood meal sources of tsetse flies. A subset (272) of the collected samples was analyzed for detection of trypanosomes species and sub-species using a nested PCR protocol based on primers amplifying the Internal Transcribed Spacer (ITS) region of ribosomal DNA. 34 blood-engorged adult tsetse midguts were analyzed for blood meal sources by sequencing of the mitochondrial cytochrome c oxidase 1 (COI) and cytochrome b (cytb) genes. We captured a total of 622 Glossina fuscipes fuscipes tsetse flies (269 males and 353 females) in the two districts with apparent density (AD) ranging from 0.6 to 3.7 flies/trap/day (FTD). 10.7% (29/272) of the flies were infected with one or more trypanosome species. Infection rate was not significantly associated with district of origin (Generalized linear model (GLM), χ2 = 0.018, P = 0.895, df = 1, n = 272) and sex of the fly (χ2 = 1.723, P = 0.189, df = 1, n = 272). However, trypanosome infection was highly significantly associated with the fly’s age based on wing fray category (χ2 = 22.374, P < 0.001, df = 1, n = 272), being higher among the very old than the young tsetse. Nested PCR revealed several species of trypanosomes: T. vivax (6.62%), T. congolense (2.57%), T. brucei and T. simiae each at 0.73%. Blood meal analyses revealed five principal vertebrate hosts, namely, cattle (Bos taurus), humans (Homo sapiens), Nile monitor lizard (Varanus niloticus), African mud turtle (Pelusios chapini) and the African Savanna elephant (Loxodonta africana). We found an infection rate of 10.8% in the tsetse sampled, with all infections attributed to trypanosome species that are causative agents for AAT. However, more verification of this finding using large-scale passive and active screening of human and tsetse samples should be done. Cattle and humans appear to be the most important tsetse hosts in the region and should be considered in the design of control interventions.
Application of a modified Poisson model in identifying factors associated with prevalence of pregnancy termination among women aged 15 – 49 years in Uganda
(African Journals Online (AJOL), 2022-10-27) Mwebesa, Edson; Nakafeero, Mary; Guwatudde, David; Tumwesigye, Nazarius Mbona
Abortion in Uganda is illegal, only permitted when it places the pregnant mother at risk. This study aimed to apply the modified Poisson model in identifying factors associated with the prevalence of pregnancy termination among women of reproductive age in Uganda. The 2016 Uganda Demographic Health Survey (UDHS) data were used in this study. More than 18,000 women of the age of 15 – 49 years participated in this study. A modified Poisson model that incorporated sampling weights was used to establish the factors associated with pregnancy termination. In Uganda, 18,506 (18.1%) had ever had a pregnancy terminated. The results revealed that, the woman’s age [APR = 3.15, 95% CI: 2.72-3.63], being married [APR = 1.55, 95% CI: 1.40-1.71], mass media exposure [APR = 1.18, 95% CI: 1.08-1.29], working status [APR = 1.21, 95% CI: 1.09-1.35], and having visited a health facility [APR = 1.20, 95% CI: 1.10-1.31] were positively significantly associated with likelihood of pregnancy termination. There exists a significant proportion of women who have had their pregnancies terminated in Uganda. It is observed that woman’s age, marital status, mass media exposure, having visited a health facility in the last 12 months and working status were main predictors. Based on these results, researchers concluded that the emphasis should be put on improving access to post-abortion care, contraceptive use and media exposure.
Application of Classical Kalman filtering technique in assimilation of multiple data types to NeQuick model
(EDP Sciences, 2022-03-03) Mungufeni, Patrick; Migoya-Orué, Yenca; Matamba, Tshimangadzo Merline; Omondi, George
This study attempts to improve estimation of ionospheric electron density profiles over Korea and adjacent areas by employing classical Kalman filtering technique to assimilate Total Electron Content (TEC) data from various sources into the NeQuick model. Successive corrections method was applied to spread the effect of TEC data assimilation at a given location to others that lacked TEC observations. In order to reveal that the assimilation results emulate the complex ionospheric changes during geomagnetic storms, the selected study days included both quiet (Kp ≤ 3) and disturbed geomagnetic conditions in the year 2015. The results showed that assimilation of TEC data derived from ground-based GPS receivers can improve the root mean squared error (RMSE) associated with the NeQuick model estimation of ionospheric parameters by ≥ 56 %. The improvement of RMSE achieved by assimilating TEC data that were measured using ionosondes was ~50 %. The assimilation of TEC observations made by the COSMIC radio occultation technique yielded results that depicted RMSE improvement of > 10 %. The assimilation of TEC data measured by GPS receiver onboard Low Earth Orbiting satellites yielded results that revealed 1 deterioration of RMSE. This outcome might be due to either the fact that the receivers are on moving platforms and these dynamics might have not been accounted for during TEC computation or limitation of the assimilation process. Validation of our assimilation results with global ionosphere TEC data maps as processed at the center for orbit determination in Europe (CODE) revealed that both depicted similar TEC changes, showing response to a geomagnetic storm.
Assessing the quality of drinking water from selected water sources in Mbarara city, Southwestern Uganda
(Plos one, 2024-03-28) Abaasa, Catherine N.; Ayesiga, Savino; Lejju, Julius B.; Andama, Morgan; Tamwesigire, Imelda K.; Bazira, Joel; Byarugaba, Frederick
This study assessed the physical, chemical, and microbiological quality with emphasis on risk score, source apportionment, geochemistry, feacal coliforms and water quality index of drinking water from selected water sources. A cross-sectional study was conducted in six villages in Mbarara city, south-western Uganda. Each selected source was inspected using a WHO-adopted sanitary inspection questionnaire. Each source’s risk score was calculated. Thirty-seven samples were taken from one borehole, nine open dug wells, four rain harvest tanks, and twenty-three taps. The values for apparent color and phosphate were higher than the permissible level as set by the World Health Organization and Ugandan standards (US EAS 12). The isolated organisms were Klebsiella spp. (8.11%), Citrobacter divergens (62.16%), Citrobacter fluendii (2.7%), E. coli (35.14%), Enterobacter aerogenes (8.11%), Enterobacter agglomerus (5.4%), Proteus spp. (2.7%), Enterobacter cloacae (13.5%), and Proteus mirabilis (2.7%). Twelve water sources (32.4%) had water that was unfit for human consumption that was unfit for human consumption (Grade E), Five sources (13.5%) had water that had a very poor index (Grade D), nine (24.3%) had water of poor index (Grade C), eight (21.6%) had water of good water index (Grade B), and only three (8.1%) had water of excellent water quality index (Grade A). The piper trilinear revealed that the dominant water type of the area were Mgso4 and Caso4 type. Gibbs plot represents precipitation dominance. PCA for source apportionment showed that well, tap and borehole water account for the highest variations in the quality of drinking water. These results suggest that drinking water from sources in Mbarara city is not suitable for direct human consumption without treatment. We recommend necessary improvements in water treatment, distribution, and maintenance of all the available water sources in Mbarara City, South Western Uganda.
Assessment of Cadmium and Lead in dried sewage sludge from Lubigi feacal sludge and wastewater treatment plant in Uganda
(Journal of Water Resource and Protection, 2019) Kyayesimira, Juliet; Ssemaganda, Abbey; Muhwezi, Godfrey; Andama, Morgan
Sludge contains organic and inorganic compounds including traces of heavy metals such as lead (Pb), cadmium (Cd), copper (Cu), nickel (Ni), chromium (Cr) and others. These metals restrict the use of sludge in agriculture because their accumulation is harmful to the environment and particularly the food chain. Cadmium and lead are among the most common heavy metals found in municipal wastewater treatment plant sludge. They are capable of bioaccumulation in plant tissues like roots and leaves and are non-biodegradable and therefore they remain in the sludge which is disposed on land or used as fertilizers on farms. The presence of heavy metal pollutants serves as a great threat to soils and also makes plants grown on such soils unfit for animal and human consumption as they may have detrimental effects to animal and human life. For instance, Pb and Cd are known to be human carcinogens. This study therefore aimed to investigate the levels of Cd and Pb in the treated dry sludge from Lubigi Feacal Sludge and Wastewater treatment plant located in Kawempe division, Kampala city, Uganda so as to ascertain its safety for use on agricultural lands. Two batches of samples were collected and analyzed at Government Analytical laboratory in Wandegeya, Uganda. The acid digested sludge samples were analyzed using Atomic Absorption Spectroscopy (AAS) method. The average concentrations of Pb found in collected sludge samples, batch 1 (11.912 mg/kg dm) and batch 2 (5.304 mg/kg dm) were far below the Environment Protection Agency (EPA) maximum permissible concentration (840 mg/kg) for any land application. Cadmium was not detected in all the sludge samples collected; there is an implication that it is either completely absent in the sludge generated by the plant or present but far below detectable levels. The sludge generated from Lubigi fecal sludge and wastewater treatment plant is therefore safe for application on agricultural lands as far as Pb and Cd concentrations are concerned.
Association between atherogenic index of plasma and prehypertension or hypertension among normoglycemia subjects in a Japan population: a cross-sectional study
(Springer Nature, 2023-06-29) Tan, Mingjuan; Zhang, Yongliang; Jin, Ling; Wang, Youli; Cui, Weiwei; Lubanga, Nasifu; He, Bangshun
The atherogenic index of plasma (AIP), consisting of triglycerides and high-density lipoprotein cholesterol, is applied to estimate the cardiovascular disease risk. The evidence regarding the association between AIP and prehypertension or hypertension remains inconclusive. This study was conducted to investigate the association of AIP and prehypertension or hypertension in normoglycemic subjects in Japan. In the present cross-sectional study, 15,453 normoglycemic participants aged 18 years or older in Gifu, Japan, were evaluated. The selected participants were separated into four groups in the light of AIP quartiles, ranging from the lowest quartile (Q1) to the highest quartile (Q4). And the association between AIP and prehypertension or hypertension was explored with multivariate logistic regression by gradually adjusting model. Among the 15,453 participants, aged of 43.7 ± 8.9 years, and of whom 45.5% were females, the prevalence rates of prehypertension or hypertension were 27.68% (4,278) and 6.23% (962) respectively. In multivariate logistic regression analyses, participants in the highest AIP quartile had an increase risk in prehypertension and hypertension, compared with participants the lowest one, the odds ratios (OR) were 1.15 (95%CI: 1.00–1.13, P = 0.045) for prehypertension and 1.54 (95%CI:1.16–2.04, P = 0.003) for hypertension after adjusting confounders. In subgroup analyses, the high risk of hypertension was also observed for female participants in the highest AIP quartile (Q4) (OR = 2.19, 95%CI: 1.37–3.49, P = 0.001), especially between the ages of 40 and 60 years (OR = 2.20, 95%CI: 1.24–3.88, P = 0.007). Conclusions Higher AIP is significantly and positively associated with the risk of prehypertension or hypertension in normoglycemic subjects in Gifu, Japan, which was more pronounced in the female population, especially between the years of 40 and 60.
Atomistic simulation of primary radiation damage profiles in fluorine-doped tin oxide thin film target using SRIM code
(University of South Africa (Unisa), 2024-11-12) Oryema, Bosco; Mtshali, Christopher B.; Madiba, Itani G.
In this study, we investigated the discrepancy between the numbers of atomic displacements obtained from the Vac.txt method and those obtained from the Vac.dam method using SRIM-2013 operated in full cascade mode. The SRIM simulations also calculated energy partitioning, damage dose and distribution profiles of the implanted He, C and O ions at three different ion energies of 10 keV, 100 keV and 1 MeV. In all the simulations and at each ion energy value, the target thickness was increased until the entire ion beam was absorbed within the target. The simulated fluorine-doped tin oxide (FTO) thin film target stoichiometrically comprised 78.6% Sn, 16.4% O and 5.0% F, and a 6.013 g/cm3 bulk density. To achieve relatively good statistics with compromised computational time, each run followed 10 000 ion histories. The results indicated that, with increasing ion energies, the peaks of vacancy concentrations moved deeper into the material. For He ions, the vacancy profiles have peaks at ∼0.04, ~0.45 and ~2.9 µm at 10 keV, 100 keV and 1 MeV, respectively. Meanwhile, for C and O ions, the peaks were at ∼0.012, ~0.15 and ~1.23 µm for C ions and ∼0.01, 0.12 and 1.2 µm for O ions at 10 keV, 100 keV and 1 MeV, respectively. We also observed that for all the ions and at all ion energies considered, the Vac.txt method predicted more vacancies than the Vac.dam method, and the discrepancies generally increased with increasing Z by an average value of ∼1.21, ∼1.45 and 1.48 for He, C and O ions respectively. In addition, the electronic and nuclear partitioning profiles revealed that most of the energies of the ions were lost in collision with atomic electrons due to ionisation and excitations, and little to nuclear events. The simulations also revealed that nuclear stopping powers increase at low ion energies. This study also indicated that damage dose profiles strongly depend on the type of incident particle and its energy. A comparison of SRIM and iradina calculated vacancies and incident ion distribution profiles generally indicated perfect agreements between the two codes. FTO thin film remains a promising material for thermal control applications in future spacecraft. However, further analyses are still necessary to comprehensively understand its evolution under intense radiation environments comprising various ions and at different energies.
The biological integrity of streams and channels draining into the Rwizi River system in Western Uganda
(East African Journal of Science, Technology and Innovation, 2019) Atwebembeire, Jeninah; Andama, Morgan; Bazira, Joel; Bunny, Julius Lejju; Tumusiime, Julius; Wangalwa, Rapheal; Yatuha, Jane
Rwizi River, often called the life-line river, supports over five million people in Western Uganda and is a major contributor of freshwater to Lake Victoria. Surrounded by a large and rapidly growing population, the river has suffered anthropogenic disturbances whose impact on the integrity of the system is a subject of concern. Aquatic macroinvertebrates, used globally to monitor both short- and long-term environmental conditions, were thus used to assess the biological integrity of streams and channels draining into the river system. Macroinvertebrates were sampled for six months in 2017 encompassing the wet and dry seasons using the kick net sampling method. The macroinvertebrates were identified morphologically using peer reviewed identification keys and their pollution sensitivity scored using the Tanzanian River Scoring System (TARISS). The Shannon diversity index was computed per site and related to average score per taxon (ASPT). We collected a total of 5442 macroinvertebrates belonging to 54 families dominated by Chironomidae (29.1%). Macroinvertebrate diversity increased with ASPT (r = 0.57; N = 131; P = 0.000). The water quality was generally poor and was not affected by the season (t = 1.03; df = 64; P = 0.303) though sites had different water quality (F = 11.32; df = 20; P = 0.000) attributed the degree of anthropogenic disturbance. We concluded that river Rwizi system is highly degraded and thus recommend restoration of the entire catchment. Aquatic macroinvertebrates are good indicators of long-term conditions but less sensitive to short-term changes. Multiple approaches, biological and chemical, are encouraged during the restoration process.
Causes of losses and the economic loss estimates at post-harvest handling points along the beef value chain in Uganda
(Journal of Agricultural Extension and Rural Development, 2019) Kyayesimira, Juliet; Wangalwa, Rapheal; Kagoro-Rugunda, Grace; Lejju, Julius Bunny; Matofari, Joseph W.; Andama, Morgan
Uganda’s beef industry has been growing slowly and requires sustained monitoring of actors at postharvest handling points in order to decrease public health risks and losses. This study documented causes of losses and estimated economic values at post-harvest handling points along the beef value chain. It was carried out at slaughter houses, transporters and butcher shops in the districts of Western, Central and Eastern Uganda. A cross sectional study was conducted among meat handlers who were interviewed to find out the losses incurred in the value chain. Microbial load from carcass swabs were collected and evaluated using standard microbiological methods to determine microbial contamination of beef. The causes of losses varied at different handling points. The actors at slaughter houses indicated the major losses were due to low beef demand (15.3%), insecurity (13.4%) and poor weight estimation methods (11.03%). Losses at the butchery included, beef waste (22.4%), drip loss (19.7%) and beef spoilage (18.4%). Microbial analysis showed the highest microbial prevalence at the butchery (70-100%) followed by slaughter (50-80%) and lastly transport (30-50%). Microbial contamination on carcass leads to spoilage and hence market loss because exportation does not admit contaminated foods. Actors reported beef waste and drip loss as the major causes of losses at the butchery. To reduce losses, public health care education for meat handlers and adherence to strict standard operating procedures (SOPs) are a key.
The challenges of reconstructing tropical biodiversity with sedimentary ancient DNA: a 2200-year-long metagenomic record from Bwindi impenetrable forest, Uganda
(Frontiers in Ecology and Evolution, 2020-07-10) Dommain, René; Andama, Morgan; McDonough, Molly M.; Prado, Natalia A.; Goldhammer, Tobias; Potts, Richard; Maldonado, Jesús E.; Nkurunungi, John Bosco; Campana, Michael G.
Sedimentary ancient DNA has been proposed as a key methodology for reconstructing biodiversity over time. Yet, despite the concentration of Earth’s biodiversity in the tropics, this method has rarely been applied in this region. Moreover, the taphonomy of sedimentary DNA, especially in tropical environments, is poorly understood. This study elucidates challenges and opportunities of sedimentary ancient DNA approaches for reconstructing tropical biodiversity. We present shotgun-sequenced metagenomic profiles and DNA degradation patterns from multiple sediment cores from Mubwindi Swamp, located in Bwindi Impenetrable Forest (Uganda), one of the most diverse forests in Africa. We describe the taxonomic composition of the sediments covering the past 2200 years and compare the sedimentary DNA data with a comprehensive set of environmental and sedimentological parameters to unravel the conditions of DNA degradation. Consistent with the preservation of authentic ancient DNA in tropical swamp sediments, DNA concentration and mean fragment length declined exponentially with age and depth, while terminal deamination increased with age. DNA preservation patterns cannot be explained by any environmental parameter alone, but age seems to be the primary driver of DNA degradation in the swamp. Besides degradation, the presence of living microbial communities in the sediment also affects DNA quantity. Critically, 92.3% of our metagenomic data of a total 81.8 million unique, merged reads cannot be taxonomically identified due to the absence of genomic references in public databases. Of the remaining 7.7%, most of the data (93.0%) derive from Bacteria and Archaea, whereas only 0–5.8% are from Metazoa and 0–6.9% from Viridiplantae, in part due to unbalanced taxa representation in the reference data. The plant DNA record at ordinal level agrees well with local pollen data but resolves less diversity. Our animal DNA record reveals the presence of 41 native taxa (16 orders) including Afrotheria, Carnivora, and Ruminantia at Bwindi during the past 2200 years. Overall, we observe no decline in taxonomic richness with increasing age suggesting that several-thousand-year-old information on past biodiversity can be retrieved from tropical sediments. However, comprehensive genomic surveys of tropical biota need prioritization for sedimentary DNA to be a viable methodology for future tropical biodiversity studies.
Characterizations of regular modules
(International Electronic Journal of Algebra, 2022-12-14) Kimuli, Philly Ivan; Ssevviiri, David
Different and distinct notions of regularity for modules exist in the literature. When these notions are restricted to commutative rings, they all coincide with the well-known von-Neumann regularity for rings. We give new characterizations of these distinct notions for modules in terms of both (weakly-)morphic modules and reduced modules. Furthermore, module theoretic settings are established where these in general distinct notions turn out to be indistinguishable.
Cloning of gonadotropin Gph-alpha, FSH-beta and LH-beta subunits and seasonal profiles of steroid hormones in wild-caught Nile perch, Lates niloticus
(Elsevier, 2022-04-05) Omony, John Bosco; Biran, Jakob; Kahwa, David; Aizen, Joseph; Golan, Matan; Nyatia, Edward; Levavi-Sivan, Berta; Rutaisire, Justus
The Nile perch (np; Lates niloticus) is a freshwater teleost species with a potential for aquaculture in freshwater surroundings. However, wild-caught breeders have persistently failed to spawn spontaneously in captivity. Cloning of the gonadotropin subunits and analysing seasonal variation in reproductive hormone levels for a 1-year period were done to gain knowledge on the physiological basis underlying the reproductive biology of np. The β-follicle-stimulating hormone (FSH-β) and β-luteinizing hormone (LH-β) subunits and their common α-glycoprotein (Gph-α) subunit were cloned using 3′ and 5′ RACE-PCR. The nucleotide sequences of the npgph-α, npfsh-β, and nplh-β subunits were 664, 580 and 675 nucleotides in length, encoding peptides of 124, 120 and 148 amino acids, respectively. The deduced amino acid sequence of each mature subunit showed high similarity with its counterparts in other teleost. Sequence analysis showed that npFSH-β is more similar to higher vertebrate FSH-βs than to higher vertebrate LH-βs. Heterologous immunoassay was calibrated to analyse pituitary LH levels. While the LH immunoassay showed parallelism of npLH with that of tilapia (ta), no parallelism for FSH was found. Levels of pituitary LH were higher in females at gonadal stages of vitellogenic oocytes, mature secondary oocytes and mature tertiary oocytes with migrating nucleus than in pre-vitellogenic oocytes and early and late perinucleolus oocytes. Using competitive steroid ELISA, variations in the levels of the steroid hormones 11-ketotestosterone (11-KT) in males and E2 in females were characterized in relation to month and reproductive index of Nile perch. Our findings show that in females, gonadosomatic index and plasma E2 were highly correlated (R2 = 0.699, n = 172) and peaked from September to November while in males, the gonadosomatic index and plasma 11-KT peaked from October to November. In female fish, both steroid hormones were detected in the plasma but greatly varied in concentrations. E2 in particular, increased with the developmental stage of the gonads. The levels of steroid hormones, E2 and 11-KT in females and males respectively increased with fish size (total lengths) and suggest that females mature at a body length of 40–59 cm than their counter part males that mature at a total length of 60–70 cm. Taken together, we describe seasonal endocrine differences in wild-caught adult Nile perch which could potentially be exploited to manipulate the reproductive axis in cultured breeders.
Compliance to riverbank regulation guidelines and its impact on the quality of River Enyau in Arua Municipality, Uganda
(International Journal of Agriculture, Environment and Bioresearch, 2019) Oloya, Geofrey; Andama, Morgan
This study documented the human activities carried out in the protected zones of river Enyau (within 30 m of river’s bank) and their influence on the quality of the river. Human activities in the protected bank of river Enyau and the quality of the river were ascertained during a field survey in March-May, 2019.The diversity of macrozoobenthic invertebrates per site and water pollution levels were determined using Shannon-Weiner (Hʹ) and Biological Monitoring Working Party (BMWP) indices respectively. Fourteen different human activities dominated by housing units (27%) were observed in river Enyau protected zones under study in Arua Municipality. Ozu-Ediofe zone corresponding directly to Arua urban center recorded the highest occurrence of the human activities (65.3%) which greatly reduced the macrozoobenthic invertebrate diversity (Hʹ=1.2) and caused pollution of river Enyau (BMWP=26.0) along that zone. The downstream zones, Onduparaka (Hʹ =2.24, BMWP=68.6) and Onduparaka-Ozu (Hʹ=1.57, BMWP=46.9) sites were both moderately polluted. On the other hand, the upstream zones i.e. Ediofe-Pajulu Bridge (Hʹ=2.52, BMWP=132.9) and Ragem Technical Institute (Hʹ=2.48, BMWP=96.2) were unpolluted and slightly polluted respectively. Hence, the implementation of the existing river bank management guidelines should be strengthened in Arua Municipality to ensure good quality of river Enyau and its sustainability.
The correlation between equatorial electrojet and equatorial ionisation anomaly over the East African region during the solar minimum period 2008-2009
(East African Journal Of Science, Technology and Innovation, 2023-09-29) Xiong, Mengqiu; Milimu, Hannington; Omondi, George; Mungufeni, Patrick
This study analyzed the correlation between the equatorial electrojet (EEJ) and the occurrence of equatorial ionisation anomaly (EIA) over the East African region. The study was carried out during both geomagnetically quiet and disturbed conditions when Kp index values were < 2+ and > 5+, respectively. The EEJ data were obtained using a pair of magnetometers located at Adis Ababa (geographic 9.04°N, 38.77°E, geomagnetic 0.17°N, 110.47°E) and Adigrat (geographic 14.281°N, 39.46°E, geomagnetic 6.0°N, 111.06°E), both in Ethiopia while the EIA data were derived from the total electron content (TEC) data that were obtained using a set of Global Navigation Satellite System (GNSS) receivers within the East African region. The data used were for the years 2008 and 2009. The TEC data over the crest of EIA were divided by those over the trough to quantify EIA strength over the region. The EEJ intensity was estimated from the difference in the horizontal component of the geomagnetic field observed by the pair of magnetometers. The results during quiet geomagnetic conditions showed that peak values of EEJ which range from 48nT - 110nT occurred between 10:00 and 14:00 LT. The EIA’s peak which varies from 1.20 to 1.45 occurs between 20:00 to 22:00 LT. The correlation coefficients were found to vary from moderate (0.58) to strongest (0.74). During geomagnetically disturbed conditions, the correlation coefficient ranges from 0.28 to 0.45. The increased eastward electric field and photo-ionization on TEC are responsible for the strong link between EEJ and EIA. This study reveals the trend in the variation of the strength of EEJ and EIA over the East African region which can be used as a basis for developing regional models to forecast or nowcast scintillations and the ionospheric space weather prediction over this region.
Cyanogenic potential of selected cassava varieties in Zombo District, Uganda
(International Journal of Nutrition and Food Sciences, 2017) Oloya, Benson; Adaku, Christopher; Ntambi, Emmanuel; Andama, Morgan
Both improved and local cassava varieties are widely grown and also, consumed in Zombo district as well as West Nile Sub region and Uganda as a whole. However, all cassava varieties contain cyanogenic glycosides which are toxic, although the amounts in each cultivar may vary considerably. Consumption of such toxins in sufficient quantities poses a health risk since they can cause acute cyanide poisoning and death in humans and animals. As such, information concerning the cyanogenic glycosides content in cassava cultivars is indispensable in averting health risks linked with cassava consumption. In this study, the cyanogenic content of the most common local cassava varieties (Bisimwenge, Nyar-anderiano, Nya-matia, Nya-pamitu, Nya-papoga and Nyar-udota) grown in Zombo district and six improved cassava varieties (NASE 3, NASE 9, NASE 14, NASE 19, TME 14 and TME 204) were investigated. Generally, the improved cassava varieties revealed lower levels (mean value was 108.75 mg/kg) of cyanogens than the local varieties (mean value was 201.65 mg/kg). The concentrations of the cyanogen in all the cultivars investigated were far above the FAO/WHO recommended value (<10mg/kg). Hence, adequate detoxification and reduced frequency of consumption of these cassava cultivars are necessary in order to limit the ingestion of toxic levels of cyanide.

Browse

Browsing Research Articles by Title

Results Per Page

Sort Options