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3 - Advanced biopolymer-based green composites: their processing and damage mechanism
(ScienceDirect, 2021-09) Mwesigwa, Ronald; Nkomo, Nkosilathi Zinti; Mwasiagi, Josphat Igadwa; Wanyama, Aaron
Composites are constructions of lightweight bearing high toughness and custom-made properties for precise use, globally. In addition, bio-based composites are constructions made from natural and/or synthetic fibers and petroleum-based polymers and/or biodegradable polymers. Furthermore, green composites are constructions obtained from biopolymers and agricultural/natural or biofibers that are more environmentally friendly hence highly sought after worldwide. Currently, green composites are offering enormous benefits that are promoting them in the automotive, packaging, construction, electrical and insulation, furniture, consumer, and household industries among others. This chapter therefore presents advanced biopolymer-based green composites in relation to their processing and damage mechanism. Subtopics covered include processing and characterization of biopolymers, agricultural/natural fibers, and green composites. Various failure and damage mechanisms pertaining to green composites are also covered.
A dye-sensitized solar cell based on an in-situ hydrothermally grown hematite photo-anode
(Springer Nature Link, 2025-07-22) Nasejje, Stella; Mukhokosi, Emma Panzi; Mmantsae, Diale
Transition metal-oxides have gained research attention for applications in optoelectronics devices like dye-sensitized solar cells (DSSCs). This contribution presents an α-Fe2O3-Pt DSSC configuration. An in-situ hydrothermal technique was used to grow spherically shaped α-Fe2O3 thin films on an FTO substrate, forming the photo-anode. The surface morphology, structural, and optical properties were characterized by standard techniques, confirming the samples’ purity. Pt was drop-cast on the FTO substrate, forming the counter electrode. The photo-anode was soaked in N719 ruthenium dye for 24 h. The electrodes were assembled using crocodile clips, and the iodide electrolyte was injected into the space between them. At an intensity of 100 mW/cm2, the α-Fe2O3-Pt DSSC yielded a short-circuit photocurrent density, open-circuit voltage, fill factor, and efficiency of 0.098 mAcm−2, 0.410 V, 0.247, and 0.01%, respectively. These results provide a simple, cost-effective strategy for synthesizing spherical nanoporous α-Fe2O3 thin films for potential application as photo-anodes in n-DSSCs.
Acid production, growth kinetics and aroma profiles of lactobacillus flora from stilton cheese
(Elsevier: Food Chemistry., 2019-02-23) Mugampoza, Diriisa; Gkatzionis, Konstantinos; Linforth, Robert S.T.; Dodd, Christine E.R.
The effect of Lactobacillus plantarum isolates from Stilton cheese on aroma profiles of milk fermentation was examined. Representative Lb. plantarum isolates were cultured alone and in combination with acid-producing and non-acid producing Lactococcus lactis NCIMB 9918 in UHT milk at 30 & 18 °C for 48 h & 12 weeks, respectively in presence and absence of salt, simulating cheese production and ripening. During long-term ripening, Lb. plantarum grew faster when co-cultured with non-acid producing Lc. lactis in the presence of salt. One isolate of Lb. plantarum produced the highest concentration of alcohols, organic acids and acetoin. Co-culture of Lb. plantarum with acid-producing Lc. lactis enhanced acid and alcohol production, whereas co-inoculation with non-acid producing Lc. lactis increased acetoin synthesis. Lb. plantarum is an incidental organism in cheese and its presence is unpredictable. Occurrence of different genotypes of Lb. plantarum could contribute to batch to batch variation in the cheese aroma characteristics.
Activity levels of gamma ray emitting radionuclides in food crop samples in selected tobacco farming areas in Aura and Maracha districts
(Kyambogo University (unpublished work), 2017-12) Anguani, Epiphany Mike
The farming activities, especially Tobacco production in Terego East and Terego West in Arua district and Maracha East County in Maracha district employ fertilizers such as NPK, DAP, CAN, TSP and UREA to enhance soil fertility property and to increase Tobacco production. Fertilizers are known to contain radionuclides such as uranium, radium, potassium etc., that originate from phosphate rocks; that could accumulate in the soil over the years and these may be absorbed by food crops grown on such soils. Humans who feed on these food crops may then absorb such radionuclides. As Human cells absorb radiation energy, molecules in them get damaged resulting into malfunction of cells through genetic mutation and this can then be a health risk. in this study the specific activity levels of gamma ray emitting radionuclides in selected food crop samples (maize, rice, sorghum, cassava, ground nuts, beans and simsim), grown in soils contaminated by fertilizers was determined using Gamma ray spectroscopy technique, that uses Nal(Tl) detector. The samples were obtained from the six Sub Counties of Omugo, Aii-vu, Odupi, Oriama, Katrini and Bileafe in Arua District and three Sub Counties of Tara, Yivu and Nyadri in Maracha District. The sampling technique used was purposive and simple random. In summary, the mean specific activity levels of radium, thorium, uranium and potassium were 64.0 Bqkg·1 , 6.0Bqkg·1, 3.5 Bqkg·1 and 185.1 Bqkg·1 respectively, in the crop samples considered. The mean specific activity levels for potassium was the highest, followed by radium, thorium ·and the least level shown by uranium. The mean absorbed dose rate was 40.9 nGy/h and the mean annual effective dose rate was 0.1 mSv/yr., for all the crop samples considered. The mean annual effective dose rate for all crop samples determined in this study were within the range recommended by the International Atomic Energy Agency as having no observable effects in the human body. Therefore it is recommended that consumption of the food crops investigated should continue as it poses no potential radiation hazard. It is further recommended that investigation should be performed on other crops which are not investigated in this study.
Advanced biopolymer-based green composites: their processing and damage mechanism
(Sustainable Biopolymer Composites : Woodhead Publishing, 2021-09-17) Mwesigwa, Ronald; Nkomo, Nkosilathi Zinti; Mwasiagi, Josphat Igadwa; Wanyama, Aaron
Composites are constructions of lightweight bearing high toughness and custom-made properties for precise use, globally. In addition, bio-based composites are constructions made from natural and/or synthetic fibers and petroleum-based polymers and/or biodegradable polymers. Furthermore, green composites are constructions obtained from biopolymers and agricultural/natural or biofibers that are more environmentally friendly hence highly sought after worldwide. Currently, green composites are offering enormous benefits that are promoting them in the automotive, packaging, construction, electrical and insulation, furniture, consumer, and household industries among others. This chapter therefore presents advanced biopolymer-based green composites in relation to their processing and damage mechanism. Subtopics covered include processing and characterization of biopolymers, agricultural/natural fibers, and green composites. Various failure and damage mechanisms pertaining to green composites are also covered.
Aerobic exercise protocol for people living with HIV : a logic model approach
(Turkish Journal of Kinesiology, 2025-06-30) Mwebaze, Nicholas; Nsibambi, Constance A. N.; Ojara, Ricky Richard; Chebet, Milton; Rukanga, Julius Ceasor; Opio, Paul; Nabaggala, Elyvania; Lumbuye, Linika; Nahwera, Loyce
There are many challenges that people living with HIV (PLHIV) often face including psychological health challenges such as muscle loss, fatigue, and mental health disorders. Regular physical activity, particularly aerobic exercise, has been shown to improve cardiovascular health, muscle strength, and mental well-being. However, there are not many clear exercise guides with evidence for practitioners and PLHIV to use as a reference while engaging in physical activities. Therefore, a structured and supervised exercise programs were designed tailored to the specific needs of PLHIV was tested and found effective. The study utilized a logic model to design, implement, and evaluate a supervised aerobic exercise program aimed at improving clinical outcomes among PLHIV. The logic model served as a framework to align inputs, activities, and expected outcomes, ensuring a systematic and evidence-based approach. A detailed exercise protocol for 6 days a week was designed for clients to engage in at least 3 days with not less than 2 days of rest in a week. A total of 135 participants were enrolled and randomly assigned 67 to experimental and 67 control group. The experimental group engaged in a five-phase aerobic exercise regimen, including warm-up, endurance training, cool-down, recovery, and flexibility exercises, performed three times per week with music set at 120–150 BPM to guide intensity. The control group was followed-up with weekly phone calls to ensure they don’t feel left out of the study. Clinical outcomes, including immunological markers (CD4 cell count), functional work capacity, and psychological well-being, were assessed before and after the intervention. Results indicated significant improvements with a p-value of < 0.01 in: aerobic capacity, muscle strength, mental health, and immune function among participants in the exercise group compared to controls. These findings suggest that this aerobic exercise protocol is a safe and effective complementary intervention for improving the quality of health in PLHIV. Incorporating supervised exercise programs using this protocol into routine HIV care could enhance long-term health outcomes and overall well-being in this population. This exercise protocol is therefore recommended for use in people living with HIV.
Aerobic-exercise training effects on immunological markers in individuals on highly active antiretroviral therapy in Uganda
(Nurtekin ERKMEN, 2024-06-30) Mwebaze, N.,; Nsibambi, C. A. N.,; Ojuka, E.,; Maghanga, M.,
There is critical relevance in understanding the multidisciplinary management of HIV/AIDs among individuals obtaining health services in Uganda. The purpose of the study was therefore to assess the effects of aerobic exercise training on immunological markers as a clinical outcome of Human Immunodeficiency Virus positive clients attending a chronic HIV clinic at a General Military HospitalBombo. A pre-post experimental design was used to understand differences between the experimental and control groups. Participants were Human Immunodeficiency Virus positive clients who had been on treatment that is, Highly Active Antiretroviral Therapy for at least 12 months. They were randomly assigned to either a control group (Group 1): who did not participate in the aerobic exercise, or an experimental group (Group 2): where a 12-week moderate intensity aerobic exercise, for not less than 3 times a week, and for at least 45 minutes per session was administered. Both groups were assessed using a physical activity readiness questionnaire. Thereafter, assessment of the clinical outcomes that is, immunological measures using Clusters of differentiation 4 were assessed. While the experimental group participated in the exercise, the control group members were followed up during the 12 weeks to ensure that they remained in the study. After the 12 weeks post-test was done. The findings of this study revealed that aerobic exercises significantly increased Clusters of differentiation 4 count in both males and females by 29.7% on average (p<0.001). Aerobic exercise is therefore likely to increase quality of life, reduce mobility and mortality rates in Human Immunodeficiency Virus positive clients on highly active antiretroviral therapy.
Aflatoxins in Uganda: an encyclopedic review of the etiology, epidemiology, detection, quantification, exposure assessment, reduction, and control
(International Journal of Microbiology, 2020-01-08) Timothy, Omara; Winfred, Nassazi; Tom, Omute; Aburu, Awath; Fortunate, Laker; Raymond, Kalukusu; Bashir, Musau; Brenda, Victoria Nakabuye; Sarah, Kagoya; George, Otim; Eddie, Adupa
Uganda is an agrarian country where farming employs more than 60% of the population. Aflatoxins remain a scourge in the country, unprecedentedly reducing the nutritional and economic value of agricultural foods. This review was sought to synthetize the country’s major findings in relation to the mycotoxins’ etiology, epidemiology, detection, quantification, exposure assessment, control, and reduction in different matrices. Electronic results indicate that aflatoxins in Uganda are produced by Aspergillus flavus and A. parasiticus and have been reported in maize, sorghum, sesame, beans, sunflower, millet, peanuts, and cassava. The causes and proliferation of aflatoxigenic contamination of Ugandan foods have been largely due to poor pre-, peri-, and postharvest activities, poor government legislation, lack of awareness, and low levels of education among farmers, entrepreneurs, and consumers on this plague. Little diet diversity has exacerbated the risk of exposure to aflatoxins in Uganda because most of the staple foods are aflatoxin-prone. On the detection and control, these are still marginal, though some devoted scholars have devised and validated a sensitive portable device for on-site aflatoxin detection in maize and shown that starter cultures used for making some cereal-based beverages have the potential to bind aflatoxins. More efforts should be geared towards awareness creation and vaccination against hepatitis B and hepatitis A to reduce the risk of development of liver cancer among the populace.
Agri-waste valorization: pathways to sustainable bioenergy and biochemical innovation
(Springer Nature Link, 2025-08-08) Mohammad, Mehdizadeh; Anahita Omidi; Rumbidzai Matindike; Zegeyesh Getachew Nigussie; Theophilus M. Ikegwu; Helen O. Agu; Patrick Onen; Ivan Gumula; Shahira M. Ezzat; Rana M. Merghany
This systematic review examines the potential of agri-waste valorization as a sustainable solution for bioenergy and biochemical production, addressing global energy demands and waste management challenges. Agri-waste, including crop residues, livestock manure, and agro-industrial byproducts, represents a critical yet underutilized resource, with over 5 billion metric tons generated annually. Current disposal practices, such as open-field burning, contribute to environmental degradation, underscoring the urgency of circular bioeconomy strategies. The review evaluates 20 peer-reviewed studies (2015–2025), highlighting thermochemical (pyrolysis, gasification) and biochemical (anaerobic digestion, dark fermentation) technologies for converting heterogeneous feedstocks into biofuels, biogas, and high-value biochemicals. Key findings reveal significant regional disparities: developing nations prioritize decentralized systems for rural energy access, while industrialized regions focus on large-scale biorefineries. Environmental benefits include greenhouse gas (GHG) emission reductions of up to 90% per kWh output when displacing specific fossil fuels (coal), though scalability is hindered by feedstock variability, high pretreatment costs, and policy gaps. Economic viability remains contentious, with profitability dependent on subsidies and market incentives. The review advocates for integrated approaches including combining machine learning-optimized processes, circular design principles, and participatory policy frameworks, to harmonize technological innovation, ecological resilience, and socio-economic equity. By redefining agri-waste as a foundation of sustainable resource systems, this work aligns with sustainable development goals, offering a roadmap for transitioning to climate-resilient, resource-efficient economies.
Analysis of fitness trends among urban dwellers in Kampala: the case of selected health clubs and fitness studios
(Kyambogo University (un published work), 2004-11) Soita, W. Paschal
Physical fitness is important in its general contribution to one s health. For effectiveness programme delivery has to be handled professionally and ethically to meet specific minimum standards. These include safety state-of-the-art equipment and trained practitioners. When well harnessed, some of societal health problems traditionally associated with hypokinetic conditions and sedentary work practices may be prevented, reduced or even eliminated. This study therefore assessed the extent to which personnel facilities and programmes within health clubs in Kampala City meet the minimum professional standards as required. To elicit the data a number of research tools were employed, including Questionnaires, Observation and Interviews with consumers and providers of products and services. A random sample of 144 (23% of the target population) subjects was selected from 12 purposively selected health clubs out of 35 considered for the study. The data collected \ as mainly subjected to qualitative treatment although at some point Chi-square, x 2,was used to establish if there existed correlation between age and gender with participation. The major findings of the study included: • Fitness as a fast-growing industry in Kampala but embroild with weaknesses in membership admission, low practitioner education levels and to a large extent obsolete equipment they use.
Analysis of injuries incurred by amateur female rugby players: A case of selected clubs in Kampala district, Uganda
(Kyambogo University[unpublished work], 2013-10) Atukei, Harriet Proscovia
Rugby players are exposed to injuries which are most especially on the upper and lower limbs since the game involves a lot of collisions. The purpose of the study was to analyse the injuries incurred by 25 amateur female rugby players in two selected clubs in Kampala District, Uganda. The objectives of the study were to establish the injuries incurred by female rugby players during rugby playing, to identify the factors that lead to injuries incurred by the female players during the game and to establish relationship between causes and injuries during training and competition. It was hypothesized that: there was no significant relationship between the occurrence of injuries and the time of the day of occurrence; and that there was no significant relationship between the occurrence of injuries and the phase of play; and finally there was no significant relationship between the occurrence of injuries and the site of the body at which the injury occurred. Questionnaires for players, coaches and medical personnel as well as an observation checklist were used to collect data. Finally, an interview guide was used to collect the information that could not be obtained using the other tools. The study was mainly quantitative in which descriptive statistics was used and data__was_analyzed using SPSS. The hypotheses were tested using Chi-square and Pearson's correlation at P < 0.05. Both frequency and cross-tables were used for data presentation. The results indicated that most injuries (92%) were bruises caused by collision with other players and many injuries (56%) were sustained during the middle phase of the games. Participants experienced most injuries around the knee and the treatment given to most injured participants (47%) was pain killers. Occurrence of injuries had no significant relationship to the time of occurrence of the injury, phase within which the injury occurred and the degree of the injury. Based on the findings, the study recommended consideration of time of the day, necessary protective gear and presence of qualified and full time medical personnel during the competitions in addition to sensitization of the teams administration and players about the usefulness of injury prevention in relation to retention and performance of the players. More research should be carried out to find out about injury management and rehabilitation of injured athletes.
Analysis of Kigelia africana (Lam.) Benth for anti-microbial activities
(Kyambogo University (Unpublished work), 2024-10) Achiro, Mary
Fungal infections and bacterial infections, including tuberculosis, are among the illnesses that have plagued humanity for a very long time. Numerous medications have been utilized to treat these infections thus far. However, there has been a challenge of microbial resistance which puts much of the population to be vulnerable to diseases and infections. There is, therefore, a need for research to overcome the existing health challenge. Throughout Africa, traditional medicine practitioners have utilized Kigelia africana as a plant remedy for persistent cough and other infectious disorders. In this research, the stem bark of Kigelia africana was analyzed for anti-tuberculosis, antibacterial and antifungal activities. 1000 g was extracted from the ground powder of stembark using dichloromethane: methanol, 1:1 for 24 h at room temperature. The extract was subjected to column chromatographic separations to obtain different fractions which were further purified and four compounds were isolated; Stigmasterol (1), a long aliphatic chain ester; 4-Hydroxyphenethyl butyrate (2), a coumarin derivative; 6- demethylkigelin (3) and Stearic acid (4). The structures were established using nuclear magnetic resonance (NMR) Spectroscopic techniques. Compounds 2 is hereby isolated for the first time from the plant whereas compound 3 is hereby reported for the first time from the stem bark of K. Africana, but previously isolated from the roots of the tree. Anti-tuberculosis activities for the plant extract and four isolated compounds were expressed as MIC values (μg/mL). Antibacterial and antifungal activities were expressed as mean zones of inhibition (mm). The crude extract was moderately active against M. tuberculosis with MIC of 44.2 ±0.5 (μg/mL). Compounds 1-3 exhibited strong activity against M. tuberculosis (33.5±0.4, 31.2±0.4 and 34.5±0.7, respectively) whereas compound 4 was moderately active (43.3±0.1) against M. tuberculosis. All the four compounds were weakly active in the antibacterial tests (7.0±0.4, 7.0±0.3, 9.5±0.7 and 7.5±0.4, respectively) and antifungal tests (8.0±0.5, 7.0±0.4, 7.5±0.4 and 7.5±0.7, respectively). There was a noticeable moderate antibacterial activity (10.0±0.3) against Staphylococcus aureus and antifungal activity (11.3±0.5) against Candida albicans exhibited by the crude extract. The findings show that K. africana stem bark has potential for treating bacterial and fungal-related diseases in addition to aiding in the fight against tuberculosis.
Analysis of the 24-h microfilarial periodicity of Mansonella perstans
(Springerlink: Parasitology Research, 2008-12-24) Asio, Santa Maria; Simonsen, Paul E.; Onapa, Ambrose W.
The Mansonella perstans microfilarial (mf) periodicity in peripheral blood was analysed in a group of 32 healthy individuals from an endemic community in Uganda. The majority of individuals had maximum mf intensity during the first and minimum during the last 12 h of the day. Mean mf ratios (i.e. time-specific counts in relation to mean count for the individual) indicated a weak but significant diurnal periodicity with peak intensity around 0800 h. Trigonometric analysis of the ratios, assuming a harmonic wave pattern of periodicity, gave a periodicity index of 11.1 and a peak time of 0645 h. The higher mf intensities in the early morning appeared to coincide with the preferred biting hour of the vectors. The observed weak pattern of mf periodicity indicates that the sampling time of blood specimens for diagnosis will have only minor effect on diagnostic sensitivity.
Analysis of the model on the effect of seasonal factors on malaria transmission dynamics
(Hindawi Journal of Applied Mathematics, 202-08) Yiga, Victor; Nampala, Hasifa; Tumwiine, Julius
Malaria is one of the world’s most prevalent epidemics. Current control and eradication efforts are being frustrated by rapid changes in climatic factors such as temperature and rainfall. This study is aimed at assessing the impact of temperature and rainfall abundance on the intensity of malaria transmission. A human host-mosquito vector deterministic model which incorporates temperature and rainfall dependent parameters is formulated. The model is analysed for steady states and their stability. The basic reproduction number is obtained using the next-generation method. It was established that the mosquito population depends on a threshold value θ, defined as the number of mosquitoes produced by a female Anopheles mosquito throughout its lifetime, which is governed by temperature and rainfall. The conditions for the stability of the equilibrium points are investigated, and it is shown that there exists a unique endemic equilibrium which is locally and globally asymptotically stable whenever the basic reproduction number exceeds unity. Numerical simulations show that both temperature and rainfall affect the transmission dynamics of malaria; however, temperature has more influence.
Anthropometric characterisation of male soccer players in northern Uganda
(Kyambogo University, 2021-08) Opiyo, Washington
The study purpose was to assess anthropometric characterisation of male soccer players in Northern Uganda. One hundred ninety-two players aged between 16 and 36years were sampled taking into account their playing positions as goalkeepers (GK), defenders (DF), midfielders (MF) and forwards (FW). Descriptive cross- sectional design was employed. The ISAK protocol was considered to measure anthropometric variables: weight; height; circumferences; n_/10; skinfolds, n_/2; and breadths, n_/6. BMI n-1, %BF, and somatotype were determined. The data was analyzed by STATA version 14C, Bartlett’s test for hypothesis done and level of significance was set at (p<0.05). The results showed that GK (71.3kg ± 4.5; 177.5 cm ± 6.7) were the heaviest and tallest compared to others and MF (67.2 kg ± 6.6; 171.6 cm ± 5.9) were the lightest and shortest.Majority (82.8%) of the players had normal BMI, with higher mean %BF (16.3%) than the recommended fat percentage(6-13%) and they showed dominancy in mesomorphic somatotype.There was no significant difference (p ≤ 0.05) in; BMI (p=0.30, F=1.22), %BF (p=0.22, F=1.49), endomorph (p=0.20, F=1.57), and ectomorph (p=0.56, F=0.68) with exception of mesomorph (p=0.01, F=3.65) that showed significant difference among players in different playing positions. The study concluded that players in Northern Uganda were generally heavier and taller with most of them having higher body fat percentage than the recommended fat percentage for soccer players. Therefore, this study recommended that coaches should design training that cater for the anthropometric requirements of each playing position to improve soccer performance. Keywords: Anthropometry, body composition, soccer performance.
Antibacterial and anticancer activities of green-synthesized silver nanoparticles using Photinia glabra fruit extract
(Nanomedicine, 2023-08) Tabbisa, Namulinda; Lei-Lei, Bao; Justus, Kwetegyeka; Ivan, Gumula; Yi-Jia, Yan; Zhi-Long, Chen
Aims: We prepared Photinia glabra (PG) aqueous fruit extract, utilized it to synthesize silver nanoparticles (PG-Ag NPs) and evaluated the antibacterial and anticancer activities of the nanoparticles (NPs). Materials & methods: Silver nitrate aqueous solution was reduced to PG-Ag NPs using aqueous PG fruit extract. NP shape, size, composition and functionalization were determined using transmission electron microscopy, x-ray photoelectron spectroscopy, Fourier transform infrared and x-ray diffraction. Results & conclusions: PG-Ag NPs were spherical, approximately 39–77 nm-sized, functionalized surfaces with notable antibacterial activity against both Escherichia coli and Staphylococcus aureus, with an MIC <30 ug/ml and cytotoxicity toward esophageal cancer cells, with IC50 values less than 20 ug/ml. PG-Ag@rt NPs have been shown to be a potent antibacterial and anticancer agent, and their enriched particle surfaces can be conjugated with other compounds for multibiomedical applications.
Antibacterial properties of phytochemicals isolated from leaves of alstonia boonei and aerial parts of ipomoea cairica
(Natural Product Communications, 2024-09-26) Gumula, Ivan; Kyarimpa, Christine; Nanyonga, Sarah Kiwanuka; Kwesiga, George; Busulwa, George; Opio, Boniface; Heydenreich, Mathias; Omara, Timothy
Objective: The leaves of Alstonia boonei and aerial parts of Ipomoea cairica are used for treatment of microbial infections among other ailments in African traditional medicine. The aim of this study was to investigate the antimicrobial phytochemicals in A. boonei leaves and Ipomoea cairica aerial parts to validate their traditional use in Ugandan herbal medicine. Methods: The plant materials were separately extracted using a dichloromethane/methanol (1:1) solvent system and subjected to repeated chromatographic separation to isolate pure compounds. The chemical structures of the isolated compounds were determined through 1H NMR, 13C NMR and 2D NMR(COSY, HSQC and HMBC). The antibacterial activity of the extracts and pure compounds were assessed using the agar well diffusion method. Results: Chromatographic fractionation of the extracts yielded trans-fagaramide and a pentacyclic lupane-type triterpenoid, lupeol, from A. boonei, and friedelin from I. cairica. Trans-fagaramide was identified for the first time in the Alstonia genus while friedelin was identified for the first time in I. cairica. The isolated compounds demonstrated antibacterial activity, with trans-fagaramide showing a minimum inhibitory concentration (MIC) of 125 μg/mL against Pseudomonas aeruginosa and 250 μg/mL against Staphylococcus aureus, Salmonella typhi and Escherichia coli. Friedelin exhibited a MIC of 125 μg/mL against Escherichia coli and 250 μg/mL against Pseudomonas aeruginosa, Staphylococcus aureus and Salmonella typhi. Conclusion: The antibacterial activities observed in this study support the traditional use of A. boonei and I. cairica by indigenous communities in Uganda for treating microbial infections.
Antimicrobial screening and characterisation of phytochemical compounds from the stem bark of Butyrospermum paradoxum
(Kyambogo Unioversity (Unpublished work), 2024-10) Eruut, David
There is a growing risk in bacterial and fungal infections as a result of increased resistance of the disease causing bacteria and fungi to the existing medicines. A lot of scientific research has therefore been directed to finding reliable alternatives to the synthetic antimicrobial agents and this has led to studies on natural products. In this study, the antimicrobial activity of the stem bark crude extracts and the pure compounds of Butyrospermum paradoxum was investigated. Extraction from the air dried powdered plant material was done sequentially using n-hexane, DCM, ethyl acetate and methanol respectively to obtain four crude extracts. The crude extracts obtained were subjected to silica gel column chromatography and further purification of different fractions was done using sephadex LH-20 to obtain pure compounds. Using various NMR techniques like 1HNMR, 13CNMR, COSY, HSQC and HMBC, the isolated bioactive compounds were characterized i.e. α-amyrin cinnamate (48), butyrospermol cinnamate (49), lupeol acetate (50) and lupeol cinnamate (51). The antimicrobial activity of the crude extracts against Salmonella typhi, Escherichia coli, Candida albicans, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus was determined using the agar well diffusion assay procedure while the MIC and MBC was determined by using the broth dilution method. All the four crude extracts were found to be active against most of the selected microbial organisms. The hexane extract was most active against C. albicans with average diameter of zone of inhibition of 14.3 mm and least active against P. aeruginosa giving a diameter of zone of inhibition of 11 mm. The DCM extract was most active against S. aureus with average diameter of zone of inhibition of 16.3 mm and was also least active against P. aeruginosa giving a diameter of zone of inhibition of 13.7 mm. . Meanwhile the ethyl acetate and methanol extracts were most active against S. typhi with average diameter of zone of inhibition of 18.0 mm and 22.0 mm respectively. The MIC and MBC values of all the crude extracts ranged between 12.5 and 50 mg/mL. The methanol extract gave the least antibacterial activity with an average diameter of zone of inhibition of 9.7 mm against K. pneumoniae. The antimicrobial activity of isolated compounds 48 and 51 against S. typhi, E. coli, C. albicans, and S. aureus was also investigated. Compound 51 gave the highest activity against C. albicans with average diameter of zone of inhibition of 22 mm and with MIC and MBC values of 0.125 and 0.50 mg/ mL respectively. Meanwhile the least activity was noted on compound 48 against S. aureus with an average diameter of zone of inhibition of 17.0 mm and with similar MIC and MBC values of 0.25 and 0.50 mg/ mL respectively. The study showed that both crude extracts and isolated pure compounds from the stem bark of B. paradoxum have significant antimicrobial activity and therefore may be used as alternative antimicrobial agents in place of the synthetic agents.
Antimicrobial, Growth, Acid and Aroma Properties of the Dominant Microflora Isolated at Different Stages of Gouda Cheese Production
(Kyambogo University [unpublished work], 2023-10) Namiiro, Josephine
The microflora of Gouda cheese is dominated by starter culture lactic acid bacteria (SLAB) and non-starter organisms, which are not deliberately added. Both of these groups of microorganisms are responsible for development of the cheese flavor and organoleptic properties during ripening. This study generally aimed to characterize the dominant microbial species at different stages of Gouda cheese production in order to identify non-starter bacterial strains with positive effects for possible application as starter culture adjuncts in fermented dairy matrices. Ten (10) independent samples from the Gouda cheese production line at Sanatos Dairies (U) Limited were collected at each of the following stages of production: raw milk, pasteurized milk, non-spiced Gouda cheese of one week, non-spiced Gouda cheese of one month, and spiced Gouda cheese of one month. The samples were enumerated within 8 h, for total viable counts (TVC), yeast and molds, total Lactococci, Staphylococcus spp., total coliforms/E. coli and total LAB using standard protocols. After enumeration of plates, colonies with different morphologies were purified (isolated) and examined for cell morphologies, Gram reaction and biochemical characteristics for presumptive identification and subsequently speciated the bacterial isolates using 16S rDNA sequence analysis. The dominant species were examined for genetic diversity using Unweighted Pair Group Method with Arithmetic Mean (UPGMA) clustering. Selected isolates from each of the major clusters were evaluated for antimicrobial activity, growth, acid and aroma production capacity in Ultra High Temperature (UHT) milk in order to prospect their possible application as starter culture adjuncts in fermented milk. LAB (2.34 - 7.77 log CFU/g) dominated the microflora of raw milk and cheese samples. TVC in respective samples corresponded with LAB counts implying that LAB were the major organisms in different samples examined. Of the 125 microbial isolates, 121 (96.8%) were found to be bacteria and were presumptively identified as Staphylococcus spp. (26.5%), Streptococcus, or Enterococcus (23.9%), Klebsiella, Enterobacter, Eschericia coli, Salmonella, Proteus, Serratia, or Yersinia (19%), Bacillus, Streptomyces, Listeria or Corynebacterium (9.9%) and Lactobacillus or Clostridium were 14.1%. 16S rDNA sequence analysis delineated 28 species with Lactococcus lactis (12.5%), Streptococcus lutetiensis (8.8%) and Lactobacillus plantarum (5%) being the major LAB species detected in all cheese samples; the rest of the isolates were either spoilage or pathogenic bacteria that could have found their way into the cheese post production. UPGMA clustering of these organisms associated them according to their different species and source of isolation; L. lactis from non-spiced Gouda cheese matured for one week were clustered together with L. lactis from spiced Gouda cheese matured for one month implying similar genetic relatedness. Each of the S. lutetiensis and L. plantarum clusters were only obtained from spiced Gouda cheese matured for one month. Thus, Lactococcus lactis and Lactobacillus plantarum were evaluated further for growth, antimicrobial activity against selected pathogenic bacterial strains, acid and aroma production properties. Single and mixed cultures of these organisms had similar growth patterns. All isolates inhibited E. coli, Salmonella and S. aureus on solid media assays but only one isolate of Lc. lactis (Gw-05) inhibited E. coli and Salmonella in the cell-free supernatant assay. In single culture, Lc. lactis had better acid production properties than Lb. plantarum. Mixed of these organisms enhanced acid production. During short term ripening, L. plantarum synthesized more organic acids, ketones, esters and aldehydes (13.7%, 2.3%, 9.3%, and 0.8%, respectively) than L. lactis which mostly produced organic acids and esters (38.7%, 6.6%, respectively). Co-culture of these organisms inhibited aroma production; only three organic acids and one ester were produced. During long term ripening, each of L. lactis and L. plantarum only produced organic acids and esters. However, L. plantarum produced more esters than L. lactis. Co-culture of the organisms enhanced aroma production resulting from synthesis of organic acids, esters and one ketone. It was therefore concluded that LAB dominate the microflora of Gouda cheese production. L. lactis has better prospects for application as primary starter culture in dairy products because they promote rapid acidification of milk, which is desirable for curd formation. Short-term fermentation of milk by single culture of L. lactis and L. plantarum enhance aroma production, while long term ripening enhances aroma production in mixed culture. Single cultures of these organisms could therefore enhance aroma formation in yoghurt, which requires short-term fermentation, whereas mixed culture could be applied in cheese, which requires long-term ripening.
Assessing games teachers' competence in training kids athletics events in primary schools in soroti city, Uganda
(Kyambogo University [unpublished work], 2023-09) Opio, Nicholas
This study assessed games teachers' competence in training kids' athletics events in primary schools in Soroti City, Uganda. The study looked at the competence of games teachers in relation to the selection and use of appropriate materials in training kid's athletics events, establish the games teachers' competence to organize and demonstrate kids' athletics events, assess challenges that affect games teachers in training kids' athletics and suggest way of mitigating the challenges that affect games teachers' competence in training kids' athletics events in Soroti City. The study was carried out to 36 Games Teachers and two hundred sixteen (216) pupils throughout eighteen (18) chosen primary schools in Soroti City, Uganda. The schools were purposefully selected and the participants were games teachers and Pupils between (7 to 14) years, this mixed methods study employed a descriptive cross-sectional design. Interviews, questionnaires, and observations were used to gather data. Statistical Packages for Social Scientists (SPSS) software was used to conduct a descriptive analysis of the data. Frequency distributions, percentages and mean tables, were used to illustrate the findings. The study results showed that game teachers knew how to choose materials and other supplies for Kids' Athletics. The teachers were competent in organizing and demonstrating shot-put (M=2.94 ±SE= 0.18), event compared to other selected activities. The major challenges observed in the study were lack of training courses and equipment that affect the training of kid's athletics programme. The study recommends that the best way to address the issues mentioned is to provide equipment and refresher courses.

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