Faculty of Science

Permanent URI for this communityhttp://localhost:4000/handle/20.500.12504/2

Browse

Now showing 1 - 20 of 246

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.
Genetic diversity in Trypanosoma (Trypanozoon) brucei isolates from mainland and Lake Victoria island populations in south-eastern Uganda: epidemiological and control implications
(Annals of Tropical Medicine & Parasitology ., 1997-11-15) Enyaru, J. C. K.; Matovu, E.; Odiit, M.; Okedi, L. A.; Rwendeire, A. J. J.; Stevens, J. R.
The Buvuma Islands, a collection of approximately 48 islands and islets, are situated off the northern shores of Lake Victoria, in Mukono District, Uganda. A mass evacuation of the islands' inhabitants was undertaken by the authorities in the 1940s because of an epidemic of sleeping sickness, the causative parasites being transmitted by Glossina palidipes (Mackichan, 1944).
Optical activity and faraday effect in some mineral and vegetable oils.
(Makerere University (unpublished work), 2000-03) Mucunguzi-Rugwebe.R.E.R
This Thesis presents results of a study of Optical Activity and Faraday Effect (OAFE) in some mineral and vegetable oils in the temperature range of 6°C to 45°C and magnetic field up to 140mT. Intrinsic birefringences responsible for Optical Activity were found in vegetable oils with impurities and all mineral oils. The results of Optical Activity in both types of oils obeyed the equation (0. 1) where Qw .,, is the angle at which minimum irradiance I min occurs in water and other substances which are optically inactive, is the rotation angle in the medium and A is a rotation due to impurity concentration. The results show that, the more the impurity concentration is in the vegetable oil, the greater the rotation angle. The rotation angle is almost directly proportional to impurity concentration. When static magnetic field was applied to mineral oils and vegetable oil with impurities, the rotation angle obeyed the equation = Ml
Effects of microstructure on mechanical strength of selected clays from Uganda
(Makerere University (unpublished work), 2004-04) Obwoya, Kinyera Sam
This thesis presents results of a study of the dependence of modulus of rupture (MOR), Young's modulus, {.E), and flexural rigidity,{ DJ, of sintered clay specimens on microstructure, average particle size and production variables. The production variables considered were sintering time, sintering temperature, and compaction pressure. The study shows that the MOR, Young's modulus and flexural rigidity of the clay product increase as compaction pressure, sintering temperature and sintering time are increased, but decrease as the particle size increases for all the processing conditions. The microstructure of clay specimens of higher strength are such that, the pores are well rounded and fewer in number. The grain boundaries are also thin and well defined with glassy phase being dominant as compared to liquid and pore phases. Higher strength of the clay specimens is also associated with formation of mullite which forms needle-shaped crystals with an interlocking network that gives high stability at elevated temperatures. The variation between MOR and sintering time, t, can be described by a relation of the form MOR = ot2 + /3t + 9 where a, /3 and 9 are constants with some of their mean values for samples compacted at 49.584MPa and sintered at 12oooc are: a = -0 .37±0.16MPas2, /3 =4.93x0.87MPas·1 and 9 = 21.05±7.26MPa
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.
The potential role of Ugandan indigenous chicken in poverty alleviation
(The Uganda Journal., 2004-12) Kyarisiima, C.C; Kugonza, D.R.; Twesigye, C.K.
This paper describes the existing production characteristics of the Ugandan indigenous chickens, highlights their potential, and suggests strategies for improvement and use in poverty alleviation programmes, emphasizing the involvement of the beneficiaries in ant-poverty initiatives. The predominance of the indigenous chickens long after the introduction of the exotic strains is presented as evidence that these chickens have the potential to form the basis for improved rural poultry production and can be transformed from subsistence to semi-commercial production systems in the poor rural households. As a way forward, a practical model is presented to demonstrate sustainability and economic viability of poultry farming based on Ugandan indigenous chicken.
An overview of significant influences and formative experiences on the development of adults’ environmental awareness in nine countries
(Taylor&Francis Online: Environmental Education Research, 2006-07-28) Palmer, Joy A.; Suggate, Jennifer; Bajd, Barbara; Ho, Roger K.P.; Ofwono‐Orecho, J.K.W.; Peries, Marjorie; Robottom, Ian; Tsaliki, Elissavet; Van Staden, Christie
This article, like the preceding one in this special issue of the journal, examines the relative importance of various categories of influence and formative life experiences on the development of environmental educators’ knowledge of and concern for the environment. It provides an overview of data deriving from nine countries (Australia, Canada, Greece, Hong Kong, Slovenia, South Africa, Sri Lanka, Uganda, UK) and highlights global similarities and differences.
Fatty acid profile and stability of oil from the belly flaps of Nile perch (Lates niloticus)
(Elsevier: Food Chemistry., 2008-05-01) Ogwok, P.; Muyonga, J.H.; Sserunjogi, M.L.
Oil extracted from the belly flaps of Lake Victoria Nile perch (Lates niloticus) was evaluated for fatty acid composition, contents of vitamin A, β-carotene and α-tocopherol, and oxidative stability. The oil was found to contain substantial amount of palmitic, palmitoleic, stearic, oleic, docosapentaenoic and docosahexaenoic fatty acids (FAs) and had high vitamin A content (3.94 ± 0.02 to 5.90 ± 0.02 mg/100 g of oil). Docosahexaenoic acid (10.45 ± 0.38%), docosapentaenoic acid (5.30 ± 0.60%) and eicosapentaenoic acid (3.63 ± 0.05%) were the most dominant polyunsaturated fatty acids (PUFAs). Ratios of PUFAs to saturated FAs were in the range 0.68 ± 0.02 to 0.74 ± 0.03, while the ratio of total ω-3 FAs to total ω-6 FAs was 0.85 ± 0.02 to 0.95 ± 0.08. The oils showed exceptional resistance to accelerated oxidation at 65 °C probably because of its high content of β-carotene (2.93 ± 0.03 to 4.69 ± 0.01 mg/100 g of oil) and α-tocopherol (2.11 ± 0.03 to 11.4 ± 0.92 mg/100 g of oil). From the results, it can be concluded that Nile perch oil is a rich source of essential fatty acids and vitamin A.
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.
Risk assessment for the occurrence of escherichia coli 0157:H7 in indigenous fermented milk (lee naga a agbora) produced in Uganda
(AJOL: Animal Production Research Advances., 2009) Wawa, SA; Sserunjogi, ML; Ogwok, P; Mugampoza, D
Different types of indigenous fermented milks are widely consumed in pastoralist communities of Africa, including Uganda. Local processing of milk generally takes place under uncontrolled hygienic conditions. Lee naga a agbora, a locally fermented milk product in northern Uganda, was evaluated for microbial contamination. The changes in pH, Total Plate Counts (TPC), Total Coliforms (TC), yeasts and moulds, and Escherichia coli 0157:H7, particularly its survival during different stages of fermentation were studied. The pH was found to decrease with fermentation time (6.54 to 4.54). E. coli was detected in most samples of Lee naga a agbora and its occurrence was observed throughout the fermentation period. The mean value of TPC (6.60± 0.10 log cfu ml-1) at the start of fermentation was significantly different (p<0.05) from that at 144 hours (7.91± 0.10 log cfu ml-1). The TPC was not significantly different (p>0.05) between 48 and 72 hours. The rate of decrease in TC counts in the initial fermentation period (0 to 48 hours) was lower than the later stages of fermentation (48 to 144 hours). Yeast and mould counts increased with fermentation time (6.20 to 7.42 log cfu ml-1). On the whole, there is risk associated with consumption of Lee naga a agbora given the occurrence of E. Coli.
A randomised, double-blind field trial of ivermectin alone and in combination with albendazole for the treatment of Mansonella perstans infections in Uganda
(Oxford Academic: Transactions of The Royal Society of Tropical Medicine and Hygiene, 2009-03-01) Asio, Santa Maria; Simonsen, Paul E.; Onapa, Ambrose W.
The effect of a single dose of ivermectin alone (150–200 μg/kg body weight) or in combination with albendazole (total of 400 mg) in Mansonella perstans infection was assessed in a randomised, double-blind field trial in two endemic communities in Mukono and Luwero districts of Uganda. No side effects were observed or reported during the first 7 days after treatment. The effect on microfilaraemia was analysed among individuals with ≥20 microfilariae (mf) per 100 μl of blood at baseline, who took the treatment and who attended follow-up examinations at 6 months and 12 months after treatment (48 and 46 in Mukono and 48 and 40 in Luwero for the ivermectin and combination treatment, respectively). In both communities, the combination treatment appeared slightly more effective than ivermectin alone, but the difference was not statistically significant. Both drug regimens were more effective in Luwero than in Mukono, probably owing to different diets in the two areas. However, in general both treatment regimens in both communities had limited effect on microfilarial intensities, and only one individual (given combination treatment in Luwero) was mf-negative at 6 months and 12 months after treatment. [ClinicalTrials.gov identifier
Mansonella perstans filariasis in Uganda: patterns of microfilaraemia and clinical manifestations in two endemic communities
(Oxford Academic: Transactions of The Royal Society of Tropical Medicine and Hygiene, 2009-03-01) Asio, Santa Maria; Simonsen, Paul E.; Onapa, Ambrose W.
Surveys for Mansonella perstans infection and potentially related clinical manifestations were undertaken in two endemic communities in Mukono and Luwero districts of Uganda where no other human filarial infections are transmitted. A sensitive and accurate counting chamber method was used for quantifying microfilaraemia in 100 μl of finger-prick blood. Among 575 and 991 examined individuals aged ≥1 year in the two communities, the overall microfilariae (mf) prevalence was significantly higher in Mukono (76.5%) than in Luwero (57.7%). As early as age 1–4 years, 40.6% and 20.5% of the children were mf-positive. Prevalences increased rapidly with increasing age to reach 89.2% and 81.4% in the 15–19 years age group and then remained high in subsequent age groups. The geometric mean mf intensity among mf-positive individuals was slightly higher in the Mukono community (32.4 mf/100 μl) than in the Luwero community (29.9 mf/100 μl), and this parameter increased with age in both communities. No obvious associations were observed between various clinical parameters and M. perstans microfilaraemia in any of the study communities. The observed patterns of microfilaraemia and the lack of obvious visible clinical manifestations suggest that the host's regulatory responses are downregulated in M. perstans infections. [ClinicalTrials.gov identifier:
Pesticide residues and heavy metals in lake Victoria nile perch, lates niloticus, belly flap oil
(Springer Link: Bulletin of Environmental Contamination and Toxicology., 2009-03-05) Ogwok, P.; Muyonga, J. H.; Sserunjogi, M. L.
Oil was extracted from the belly flaps of varied sizes of Nile perch caught from Lake Victoria (Uganda). The oil was analyzed for pesticide residues and heavy metals. Total residual concentration of dichlorodiphenyltrichloroethane, endosulfan, hexachlorocyclohexane, hexachlorobenzene, heptachlor, chlordane, endrin, aldrin and chlorofenvinphos increased significantly (p < 0.05) with fish size. Mercury and lead were detected in most samples while arsenic and cadmium were below detection limits. Nile perch may, therefore, accumulate significant amount of chemical contaminants. Levels of contaminants in Nile perch oil were, in general, within limits considered acceptable by the stringent German Food Law for human consumption.
Assessment of selected health related fitness components of the Uganda Police Force from the Central region of Uganda
(Kyambogo University(Unpublished work), 2009-08) Balagana, Charles G. M.
This study was conducted in the Police force from the central region of Uganda. The objectives of the study were: to establish the fitness levels of the Uganda Police force with regard to selected fitness variables and to ascertain the relationship between duty performance and the selected fitness variables in the police force. Four (4) health related physical fitness components were assessed and these are: Aerobic endurance, Flexibility, Strength endurance and Percent body fat. The sample comprised of 60 subjects split equally between the Traffic police and the Riot police departments. A pre-experimental research design was used in this study. Purposive sampling procedure was employed in selecting the Police Departments. Stratified random sampling procedure was used in selecting the subjects and simple random sampling technique was used to choose the subjects per their duty stations, within the same department and of the same gender. The results were then compared to the already established norms as published by the American Alliance for Health, Physical Education, Recreation and Dance (AAHPERD 1985). Fitness tests for each of the selected fitness components were carried out and the data obtained was compared with the norms as established by AAHPERD (1985). There after, the data was analyzed using the analysis of variance (ANOV A) method in order to test the research hypotheses. For the aerobic condition, 73.3% from the traffic police department and 53.3% from the riot police department showed bad aerobic condition. For strength endurance levels; 60% of the subjects from the traffic police department scored strength endurance levels below average while 50% of the subjects from the riot police department scored above average. On the side of flexibility scores; 66.6% of the total sample from the riot police department had flexibility scores above the average mark while 50% of the total sample from the traffic police had their flexibility scores above the average mark. The flexibility scores from both the riot and traffic police departments therefore put all the subjects within the acceptable range. Body composition results revealed that there was no subject that was over fat from both the riot and traffic police department. It was recommended that regular fitness test programmes should be initiated in the Uganda police force.
Speciation of heavy metals in water from the Uganda side of Lake Victoria
(International Journal of Environmental Studies, 2010-02) Jolocam, Mbabazi; H., Twinomuhwezi; J., Wasswa; M., Ntale; G., Mulongo; J., Kwetegyeka; K.H., SchrǾder
Different forms of copper Cu, zinc Zn, lead Pb and cadmium Cd in water from the Uganda side ofLake Victoria (25°C, pH 6.75–7.18), the second largest inland freshwater lake in the world, havebeen studied using ion-exchange, dialysis and atomic absorption spectrophotometry. The resultsindicate that heavy metals Cu, Zn, Pb and Cd are present mainly in the cationic form (80–83%).Small quantities of anionic (13–22%), non-ionic, dialyzable (4–8%), and non-ionic, non-dialyzable(< 1.3–4.4%) forms were also detected for all metals except Cd. The corresponding concentrationslay in the ranges: cationic, 0.06–0.99; anionic, < 0.001–0.25; non-ionic, dialyzable, < 0.001–0.08;non-ionic, non-dialyzable, < 0.001–0.06 μg ml−1. The existence of the metals in non-ionic and non-dialyzable forms is attributable to metal associations with high relative molecular mass (RMM)organic matters.
Speciation of heavy metals in water from the Uganda side of Lake Victoria
(International Journal of Environmental Studies., 2010-02-15) Mbabazi, Jolocam; Twinomuhwezi, H.; Wasswa, J.; Ntale, M.; Mulongo, G.; Kwetegyeka, J.; SchrǾder, K.H.
Different forms of copper Cu, zinc Zn, lead Pb and cadmium Cd in water from the Uganda side of Lake Victoria (25°C, pH 6.75–7.18), the second largest inland freshwater lake in the world, have been studied using ion‐exchange, dialysis and atomic absorption spectrophotometry. The results indicate that heavy metals Cu, Zn, Pb and Cd are present mainly in the cationic form (80–83%). Small quantities of anionic (13–22%), non‐ionic, dialyzable (4–8%), and non‐ionic, non‐dialyzable (< 1.3–4.4%) forms were also detected for all metals except Cd. The corresponding concentrations lay in the ranges: cationic, 0.06–0.99; anionic, < 0.001–0.25; non‐ionic, dialyzable, < 0.001–0.08; non‐ionic, non‐dialyzable, < 0.001–0.06 µg ml−1. The existence of the metals in non‐ionic and non‐dialyzable forms is attributable to metal associations with high relative molecular mass (RMM) organic matters.
Heavy metal contamination in vegetables cultivated on a major urban wetland inlet drainage system of Lake Victoria, Uganda
(International Journal of Environmental Studies, 2010-06) Jolocam, Mbabazi; J., Wasswa; J., Kwetegyeka; G.K., Bakyaita
The population of the Ugandan capital, Kampala, located close to Lake Victoria, appears to be exposed to risk of ingesting the heavy metals Cadmium (Cd) and Lead (Pb) through vegetables in their diet. Lake Victoria is responsible for frequent torrential polluted runoffs in the city. The Nakivubo channel, the city’s major wetland drainage system, empties directly into the lake. Vegetables are grown on the urban wetland soils. Heavy metal content in vegetables from the wetland cultivation sites was determined by wet acid digestion, with 87–92% recovery. The results showed that although the heavy metal levels of manganese (Mn), zinc (Zn), cadmium (Cd) and lead (Pb) were significantly higher than those in similar food crops from rural control sites, only Cd and Pb exceeded the World Health Organisation (WHO) maximum permissible levels. Cd and Pb pose serious human health risks. Early pollution control measures are advisable.
Ineffectiveness of Nakivubo wetland in filtering out heavy metals from untreated Kampala urban effluent prior to discharge into Lake Victoria, Uganda
(African Journal of Agricultural Research, 2010-12) Jolocam, Mbabazi; J., Kwetegyeka; M., Ntale; J., Wasswa
The population of the Ugandan capital city of Kampala has dramatically increased since the political turmoil of the 1970s and with it a considerable rise in industrialisation. Few manufacturing plants, however, have pretreatment installations in place for their polluted effluent prior to discharge into the surrounding ecosystems. Kampala’s main drainage system is the Nakivubo channel which empties directly into the neighbouring Lake Victoria, the second largest inland freshwater lake in the world. Increased urban effluent load coupled with reclamation for crop farming have considerably reduced the effectiveness of the wetland to filter out major pollutants, in particular heavy metals. Using atomic absorption spectrophotometry, this study showed that the efficiency in sieving out zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) has shrunk from 89.7 – 98.3% in December 2006 to 79.4 – 92.1% in December 2008, over a period of three consecutive years. This is indicative of the growing ineffectiveness of the wetland to absorb heavy metals. Levels of the same metals in the lake water some two kilometres away from the mouth of the wetland have correspondingly increased from 23 - 31% to 35 - 47% in the same period. This poses a serious threat to the quality of the fish and to the over two million urban population that directly depend on the lake water for domestic and industrial use. The remedy lies in the relevant authorities to enforce pretreatment at each factory site, increased factory management sensitisation on environmental concerns and more stringent measures against wetland encroachment.
Nitrification in modified sewerage stabilisation ponds prior to discharge into the Ugandan side of Lake Victoria
(International Journal of Environmental Studies., 2010-12-08) Mbabazi, Jolocam; Wanasolo, W.; Gava, J.; Kwetegyeka, J.
Large volumes of wastewater in the Ugandan capital Kampala have seriously polluted Lake Victoria, from which the city draws its freshwater. Untreated effluent drains directly into this lake. In tropical temperatures, oxidation ponds are used for wastewater treatment, especially for organic matter. This technology should be the focus of work to improve its efficacy, and thus to secure the sustainability of the lake and its freshwater fish which are marketed worldwide. A pilot scale plant was set up comprising an anaerobic tank, a facultative pond and four fibre‐glass maturation tanks. The total nitrification rates in the tanks T1–T4 were 5.5, 7.5, 10.1 and 6.4 (±0.4) mg‐N/l/day, respectively. For more efficient wastewater treatment stabilisation pond systems, a modification similar to that in T3 should be considered. T3 was constructed with biofilm attachment surfaces in a manner which allowed effluent to be channelled round them, contrary to direct T1 flow which is currently in use.
Occurrence of listeria monocytogenes in bulked raw milk and traditionally fermented dairy products in Uganda
(African Journal of Food, Agriculture, Nutrition and Development., 2011) Mugampoza, D; Muyanja, CMBK; Ogwok, P; Serunjogi, ML; Nasinyama, GW
Bulked raw milk, locally processed yoghurt (LPY) and Bongo, a traditionally fermented dairy product sold at most informal milk cooling points in Uganda, were assessed for occurrence of Listeria spp. and Listeria monocytogenes. Total plate counts (TPC), holding temperature, pH and titratable acidity were also determined in all the milk products at the point of collection using standard methods. A total of 40 samples of bulked raw milk and 30 for each of LPY and Bongo were examined. Listeria spp. was higher in bulked raw milk than in fermented milk. Listeria spp. were detected in 60% of bulked raw milk, 30% of LPY and 15% of Bongo samples. Bulked raw milk had significantly higher (p<0.05) mean Listeria counts (3.10±0.06 log10 cfu mL-1) than LPY and Bongo, 0.82±0.18 and 0.32±0.18 log10 cfu mL-1, respectively. L. monocytogenes was isolated from 13 % of bulked raw milk, 3.0% of LPY but was not detectable in Bongo. Total plate count was significantly different (p<0.05) among the different milk types studied. Bongo had higher TPC (9.00±0.13 log10 cfu mL-1) than bulked raw milk (8.40±0.11 log10 cfu mL-1) and LPY (7.40±0.13 log10 cfu mL-1). The mean total plate counts (4.90 to 9.00±0.13 log10 cfu mL-1) of the fermented dairy products were within the acceptable limits for human consumption. The TPC for bulked raw milk (8.40±0.11 log10 cfu mL-1) was higher than the recommended values of national and international standards. Temperature, pH and titratable acidity were significantly different (p<0.05) among the different milk types. Holding temperature ranged from 5.40 to 8.60oC, pH was 4.20±0.04 to 6.10±0.04 whereas titratable acidity ranged from 0.22±0.01 to 089±0.01%. Listeria counts were not statistically predictable (p>0.05) from variation in the combined effect of pH, percent titratable acidity and temperature. Results of this study demonstrate a high risk associated with consumption of bulked raw milk and fermented dairy products in due to occurrence of Listeria spp.

Browse

Browsing Faculty of Science by Issue Date