School of Biosciences (Biosciences)

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Assessing the impact of biological control in the Rivers Kagera, Mara, Pangani and Sigi.

(Makerere University, 2007-07) Katagira, F.

Water hyacinth Eichhornia crassipes (Martius) Solms-Laubach, is considered to be the worst aquatic weed worldwide. Biological control using Neochetina weevils was initiated in Tanzania in1995; however this control mechanism was successful in Lake Victoria where water hyacinth was reduced by 80%, but failed in some water bodies (Rajabu et al., 2000; LVEMP, 2001). Studies were conducted during 2003 to 2005 to assess the impact of biological control in the rivers Kagera, Mara, Pangani and Sigi and to evaluate potential effect of nitrogen, phosphorus and silt on weevil establishment in greenhouse conditions at Kyaka near Kagera river in Kagera region, Tanzania. The objectives were achieved by studying the following aspects: (i) The status of water hyacinth and Neochetina weevils in fresh water rivers (Kagera, Mara, Pangani and Sigi rivers) of Tanzania; (ii) Effect of nitrogen and phosphorus on weevil establishment and damage on water hyacinth; (iii) Effect of silt on establishment and performance of Neochetina weevils on water hyacinth; and (iv) Effect of water quality on weevil establishment and damage on water hyacinth. The study on rivers involved sampling of water hyacinth and determination of population densities and growth. Weevil densities, stages of development and feeding scars were also determined. Results showed that Kagera river had the highest water hyacinth densities (44.2 plants m-2) followed by Mara (32.8 plants m-2), Pangani (27.2 plants m-2 ) and least in Sigi (22.8 plants m-2). Plant height was highest in Mara (51.04 cm), followed by Kagera, Pangani and the least height in Sigi (28.6 cm). Other plant parameters namely, leaf length and width and root length followed the same trend. Kagera river had the highest number of ramets per plant (1.13) followed by Mara, Sigi and Pangani (0.69). The number of adult weevils per plant was highest in Sigi (1.93) and Pangani (1.78) and lowest in Kagera and Mara (0). The number of weevil feeding scars per plant was highest in Pangani (22.1) and Sigi (17.81). Overall Mara (1.4) and Kagera (0.21) had the lowest. Water hyacinth growth suppression and population reduction was only evident in Pangani and Sigi rivers and was associated with abundance and feeding by weevils. On the other hand, the weed continued to proliferate in Kagera and Mara rivers in Lake Victoria basin despite monthly weevil releases. The effect of N and P on water hyacinth growth and Neochetina weevil establishment and efficacy was conducted under greenhouse conditions. It consisted of 0 (control), 50 mg N L-l , 100 mg N L-l, 42.5 mg P L-l and 85 mg P L-l and their combinations. Weevil damage was suppressed at higher N (100 mg N L-l) but not high P application rates. Plants fed with high levels of N had low counts of adult weevils and pupae. On the other hand, growth of water hyacinth was limited in low N by 40%, yet weevil numbers, eggs, larvae and pupae per plant as well as weevil damage, increased at low N. Similarly, the number of adult weevil feeding scars per plant was higher (P<0.01) in lower N than at high levels. However, P concentration had no significant effect on number of weevil feeding scars per plant. Total plant N and P varied among nutrient application rates and N uptake depended on P availability; and plant N content increased with increase in P application rate. There was a significant positive correlation (P<0.001) between number of eggs and larvae per plant. The number and length of roots per plant increased with P application while application of N resulted to significant reduction in number and length of roots per plant. Water quality in the Kagera, Mara, Pangani and Sigi rivers differed. The highest total nitrogen was found in Kagera (0.99 mg N L-l) while the lowest was in Sigi (0.12 mg N L-l). Similary, total phosphorus was highest in Kagera (0.36 mg P L-l), while the lowest was in Sigi (0.12 mg P L-l). Likewise, electrical conductivity was highest in Kagera (969.8 µscm-l) follwed by Mara while Pangani and Sigi had the lowest indicating pollution loads in Kagera and Mara rivers. Water temperature was high in Pangani (30.39 oC) and Sigi (29.4 oC), while Mara had (26.2 oC) and Kagera had the lowest (26.23 oC). Air temperatures and relative humidity followed the same trend. It was concluded that high N and P levels might be partly responsible for poor weevil damage on water hyacinth in eutrophic habitat such as in Kagera and Mara rivers. On addition, the low temperatures and relative humidity may have contributed by limiting the weevil activities. The study on the effect of silt on the water hyacinth and weevil development and efficacy consisted of control (no silt applied) and silt at levels 17 kg, 51 kg and 85 kg in 50 litres of water applied in order to achieve distances of 20, 10 and 0 cm between the root tips and silt topmost level/surface. Silt and water for the experiments was from Lake Victoria and Kagera river. There was reduced weevil reproduction in treatments with silt as evidenced by low numbers of eggs, larvae, pupae and adult weevils. In contrast water hyacinth plant populations, leaf length and number of ramets were significantly enhanced (P<0.05) by silt application. Water hyacinth grown in water and silt from Kagera river, had higher weevil feeding scars per plant were 32.2 at low silt (17 kg) and 8.7 at 85 kg silt level indicating reduced weevil damage at high silt. A significant and positive relationship (r = 0.881, P < 0.01) was obtained between water hyacinth leaf length and lamina width. Silt levels appear to directly affect different life stages of the weevil, thereby reducing the ability of the insects to multiply to populations that can suppress growth of water hyacinth. Sediment loads in Kagera and Mara rivers may have contributed to poor establishment of Neochetina weevils and favoured water hyacinth proliferation.
The molecular biology of sulfadoxine-pyrimethamine drug resistance of plasmodium falciparum strains in Uganda

(Makerere University, 2007-08) Sendagire, Hakim

In November of 2000, Uganda changed its anti-malarial policy to replace chloroquine (CQ) with a combination of CQ and sulphadoxine–pyrimethamine (SP) as the first line agents. The idea of the combination was to delay the development of malaria resistance to either drug when used alone. Information was limited on the efficacy of either drug yet SP resistance was increasing in East Africa. SP resistance has been associated with point mutations in Dihydrofolate reductase (DHFR) and Dihydopteroate Synthase (DHPS) in vitro, but correlations with in vivo outcomes are less clear. Four separate studies were done over a four-year period, to monitor and evaluate the rate of development of resistance using both clinical and molecular methods. In 1999 in Kampala, Uganda, adults and children with uncomplicated falciparum malaria were treated with SP (1.25 mg/kg pyrimethamine, 25 mg/kg sulfadoxine) and assessed using WHO clinical and parasitological criteria. Analysis of DHFR/DHPS mutations was done using PCR and restriction endonuclease digestion methods. Clinical treatment failure was 11% at 14 days, increasing to 30% at 28 days, after excluding new infections. Mutations in DHFR 108-Asn (94%) and 51-Ile (91%) were very common. All infections with less than two DHFR/DHPS mutations were successfully treated. The prevalence of DHFR 59-Arg (57%), DHPS 437-Gly (58%) and 540-Glu (66%) was lower, with many samples showing a mixed wild-type and mutant profile. DHFR 59-Arg, DHPS 437-Gly and 540-Glu showed clinical significance mostly at day 28 {DHFR 59 (0.061 by day 14 and 0.003 by day 28), DHPS 437 (0.072 and 0.015) and 540 (0.031 and 0.0007) on days 14 and 28 respectively for each codon}. Combining them, 59-Arg + 540-Glu had the strongest association with clinical outcome at 28 days (p=0.002). To examine the theory that increasing resistance is associated with increasing number of mutations, there was a 50% risk of treatment failure in patients with 5 mutations than 0-4 mutations (p=0.0001). The second study was designed to provide baseline information on the efficacy of SP and the prevalence of molecular markers that are associated with SP resistance in Kasangati. Blood samples were collected on Whatman’s filter paper from 169 consenting patients who were diagnosed with malaria. Patients were treated with SP and followed for 14 days. SP monotherapy was efficacious for 140 of 163 (85.9%) treated patients. We found a high level of mutations in alleles that have previously been reported to be associated with SP resistance, but there was no statisticall significant relationship between clinical outcomes and molecular markers (P. value 0.106). With the exception of codon S108 in DHFR (DHFR S108N was at 94.9%), frequencies of DHPS mutant and mixed alleles combined (A437G 89% and K540E 83.9%) were higher than those of DHFR (N51I 58.4%, C59R 31.3%). The last two studies were done to evaluate the national anti-malarial policy drugs and assist evidence based national policy guidelines. We compared the clinical, parasitological and molecular findings of one study with treatment arms of CQSP, amodiaquine (AQ) plus SP (AQSP) done in 2003 with a study done 1 year earlier (2002) using SP alone There was a notable decrease in adequate clinical response (ACR) by day 14 from 92.7% with SP to 80% with the combination CQSP, a year later. AQSP combination was found to have the best effect (ACR 94.3% compared to CQSP 80%, p. value 0.008). There were no early treatment failures in the AQSP group. Treatment failures were recorded at 20% on day 14 and 43% on day 28 for CQSP treatment and 5.7% by day 14 and 28.8% by day 28 in the AQSP group. The number of mutations that are associated with SP resistance increased from 2002 to 2003 at all loci monitored, from 83.8 to 100% at codon 108, 58.7 to 76% at codon 59 in the DHFR gene, and from 58.8 to 86% at codon 437 and 33 to 43% at codon 540 in the DHPS gene. We conclude that there has been a rapid development of resistance since the introduction of new policy guidelines. AQSP was found to be a superior drug combination compared to CQSP and could be used as a low cost alternative to co-artem at the moment.
Phytochemical and bio-activity evaluation of Commicarpus plumbagineus standl: A medicinal plant used traditionally in reproductive health care in Uganda

(Makerere University, 2007-09) Ojok, Miriam Fiona

Commicarpus plumbagineus Standl. (Nyctaginaceae) is a traditional medicinal plant used to treat a variety of diseases including urinary tract infections, prevention of miscarriages, purification and improvement of blood texture, fibroids, dysmenorrhoea, hypermenorrhoea and coagulation of blood. However, no scientific validation on the claimed cure of diseases by C. plumbagineus had been carried out and as such; the chemical profile and bioactivity were not known. This research was carried out to upgrade herbal medicine through scientific validation and evidence-based research on bioactivity. The leaf and stem of C. plumbagineus were collected, dried and extracted in diethyl ether, ethanol and water. The tests carried out included; uterine motility, phytochemical screening, antimicrobial (disc diffusion method) and whole blood and ELISA assays for immunology. Phytochemical results revealed that saponins, glycosides, sugars, oleanolic acid, blue terpenoids, steroids, phytosterols, carboxylic acid and nitrogen containing compounds were abundant as in other species found in Nyctaginaceae. Antimicrobial tests showed that the plant was inactive at 50% (0.05g/ml) on both Candida albicans and Staphylococcus aureus therefore did not show antimicrobial activity. Immunology tests revealed that the stem and leaf aqueous extracts induced higher IFN-gamma (responsible for antibody production) as compared to IL-10 (associated with successful pregnancies) even after stimulation with PHA (mimics an infection). The plant is therefore an immune booster. Uterine motility results showed that the leaf aqueous extract caused uterine relaxation at 10% (0.01g/ml) through to 80% (0.08g/ml) and the stem extract caused uterine relaxation at 80% (0.08g/ml). The relaxing effect on the uterine muscle by C. plumbagineus supports the prevention of miscarriages, dysmenorrhoea and hypermenorrhoea. There is need for more research in the areas of dosage, toxicity, invitro tests and broad spectrum antimicrobial activity.
Restoration potential of species in the degraded forested sites in Kibale National Park, Uganda.

(Makerere University, 2009-02) Omeja, Aria Patrick

Introduction: Kibale National Park (KNP), like most protected areas in Uganda has had many challenges over the years. In 1971, illegal destruction and encroachment occurred in the game corridor which linked Kibale National Park with Queen Elizabeth National Park, but ended in 1992. Kibale National Park, currently managed by the Uganda Wildlife Authority (UWA), was under the Forest Department before to 1993. One of the management objectives of Forest Department then was sustained production of wood and timber. To achieve this, plantations of exotic tree species were established in 1950 –60s (Osmaston 1959). When UWA took over management of these areas, the management objective changed, and plantations of exotic tree species were clear-felled and the areas left to regenerate naturally. In the southern boundary of the park at Mainaro where elephant grass and Lantana camara had suppressed tree regeneration, intensive reforestation has been undertaken. Since areas of the park are now recovering from historic human impact, there is a need to examine the effectiveness of different management schemes to restore the forest cover. This is a subject that has not been much studied in Kibale or elsewhere, but is required to guide natural forest planning and management, hence, the need for this study. Objectives: The general objective of the study was to evaluate the restoration of woody tree biomass and tree species richness that occur through different land use and management options in Kibale National Park (KNP) and the specific objectives were: (i) To develop a general above ground allometric equation that can be used to calculate overall above ground biomass of standing trees in the disturbed areas of Kibale National Park; (ii) To determine the amount of biomass accumulation and species richness in an abandoned former pine plantation; (iii) To determine the significance of enrichment planting using indigenous tree species after pine plantation establishment and removal; (iv) To evaluate how successful the restoration efforts conducted in Kibale have been, and in comparison to other areas around the tropics; and (v) To find out the most cost efficient approach to promote restoration in the degraded sites in KNP. Methods: Most published allometric relations are typically site-specific, reflecting the original objective for which they were developed (Girgal & Kernik 1984; Pastor et al. 1984) and are not developed for regenerating forest. Since, this study was conducted in an area that was a young regenerating forest, an allometric regression equation of biomass accumulation of woody trees species for this specific area was developed by selecting a sample of early successional trees of varying sizes for harvest and determining their dry weight. This follows methods that rely on the combination of regression equations to produce either species-specific allometry or allometry for groups of species (Jenkins et al. 2003; Keith et al. 1999; Lwanga 2003). Trees in forest lands that were adjacent to the park were identified, and their stem diameter were measured at 0.3 m and 1.3 m above the ground hereafter referred to as diameter at ground height (DGH) and diameter at breast height (DBH) respectively. The trees were then cut and their total lengths measured. Individual trees that were of similar size to those regenerating in the study area (i.e., DBH 1.1 – 10.0 cm and DGH 1.6 – 11.0 cm; within the weights of 0.25 – 10 kg; n = 200) were selected. The choice of tree species for biomass estimation was made based on survey of the vegetation of common tree species in the study area. In total, 200 stems (20 stems per species) were harvested. The species included Albizia grandibracteata Taub., Bridelia micrantha Baill., Celtis africana Burm. f., Celtis durandii Engl., Clausena spp, Maesa lanceolata Forssk., Funtumia latifolia Stapt, Milletia dura Dunn., and Trema orientalis Blume. First, the branches were removed and the total weight of stems and leaves determined. Second, the tree stems were cut into smaller sections and air dried in the laboratory until constant mass was attained. Once all components had reached a constant dry weight, the total weight of the tree was estimated. Findings: The most pressing issue in many regions including Kibale has been the need to assemble information on detailed above ground biomass allometric relationship for the woody tree species on degraded areas. This study has made the first move towards providing such information for this region. The results from this work do not only enhance our understanding of the effects of anthropogenic activities on the forest ecosystem, but also provide much needed information that will facilitate planning, development, and management of forest resources in the degraded areas. It is worth noting that, over the last two decades, there has been a great deal of clearing of forested areas driven by the need for more agricultural land, fuel wood, and building materials for the rapidly expanding human population in the region (Chapman & Chapman, 2003). In 1997, National Environment Management Authority estimated that wood fuel provided 99.2% of energy used for cooking in Kabarole district of Uganda that hosts over 50% of the 795 km2 of KNP. However, comparison of results of the present study and those from Lwanga (2003) and Naughton & Chapman (2002) indicated a significant change in tree species composition and woody tree biomass of KNP, a change that is attributed to a large extent to the recovery of the tree species after disturbance. Other studies within KNP have discovered a number of pits for storing grain and an array of potshards in an area that have traditionally been considered undisturbed forest (Lang Brown and Harrop 1962). It therefore seems likely that in tropical forests, such as Kibale, human activities have altered forest composition for a considerable period of time. Differences in tree biomass and forest composition between areas may reflect the period of time that the area has had to recover from human induced disturbance. However, based on what is known about the life history of the canopy trees in Kibale, distinguishing an area that had been disturbed 1,000 years ago from one that had been disturbed 400 years ago would be a very difficult task. Conclusion: (i) The following allometric equation can be used to estimates the above ground as an indication of forest restoration: y=2.053x + 2.056: (R2 = 0.653, n =200); (ii) Restoration efforts conducted in Kibale and elsewhere around the globe all appear to be successful, based on a long term-time frame. This highlights the resilience of tropical forest systems to recover from disturbance; (iii) Given the three restoration projects evaluated within Kibale, fire protection for 12 years resulted in the biomass accumulation of 2,858 kg/ha/year. The effect of pine establishment and their harvest resulted in the rate of biomass accumulation of between 1,735-2,720 kg/ha/year. The enrichment planting resulted in biomass accumulation of 1,306 kg/ha/year, and fire control after 32 years resulted in the accumulation of 933 kg/ha/year. These amounts of biomass accumulated indicate that the forest is being restored and will play a significant role in atmospheric carbon absorption; (iv) Enrichment planting after pine plantation establishment and removal does not contribute significantly to biomass accumulation, counter to earlier reports presented to UWA. This suggests that UWA should more strongly request that the long-term researchers of Kibale provide data or impressions about future management plans; (v) Given the level of biomass accumulation in the different treatments considered, it can be said that fire protection is the most cost efficient approach to promote restoration in this region and it provides suitable incentives for the involvement of local communities. Recommendations: (i) Both the prevention of fires and the enrichment planting, such as that conducted at Mainaro, appear to provide positive social benefits for the local communities. However, in the future, the research community (anthropologists or sociologists) working in conjunction with UWA and international conservation biologists should evaluate if the benefits to the local communities (e.g., employment) result in more positive impressions of the park by the local community and if this potential positive impression translates into reduced illegal practices conducted by the local community; (ii) Given the extensive cover of Lantana camara, in the restoration compartments in the south of Kibale and its potential to negatively influence restoration in the future, an assessment on the value that L. camara removal would have on tree regeneration should be a priority for future research.
The effects of fire on the regeneration of acacia species in Lake Mburo National Park, Uganda

(Makerere University, 2009-06) Badaza-Nakileza, Rose Susan

The thesis investigated the effect of fire on the regeneration of Acacia species in Lake Mburo National Park, Uganda. The mechanism that cause the effects and the manner in which the effects are influenced by fire are also discussed. The study was carried out in Lake Mburo National Park between 1997 and 1998. To explain the relationship between the incidence of herbivory and the height and position of the sprouts, the effects of fire and cutting were investigated. All sprounts were monitored for incidence of herbivory. Results of fire experiments in five sites in Lake Mburo National Park showed that the quantity and quality of fuels available for fire varied widely in relation to weather but also in relation to the degree of use by man and herbivores. The amount of phytomass available was an important factor in determining the fire intensity, scorch height and char height. Furthermore, the intensity of fire also depended on the season and frequency of burning. Wet periods which foster shrub establishment also promoted abundant grass growth. However, frequent burning prevented the building up of fuel load sufficient to support a high intensity fire. Although fire induced the germination of all Acacia species in the study, the ability of seeds to germinate depended on the fire intensity and the seed size. Low fire intensities induced the germination of Acacia hockii seeds. However, these positive effects of fire on seed germination were short lived and only 20% of the seedlings got established. The population structure of Acacia species was investigated and non- uniform population structure was found. The results indicated that population structures differed widely among stands and changes in population structures after fire varied from site to site depending on the fire intensity and Acacia species. Although Acacia hockii was found to be dominant, most individuals were trapped in the lower height size classes. While fire intensity was the prime factor influencing the effects of fire on Acacia species, increase populations of species can also be attributed to frequent burning and increased human activities in and around Lake Mburo National Park. The results of this study indicated that frequent burning and the subsequent low intensity fires experienced in Lake Mburo National Park favoured the proliferation of Acacia hockii. The factors that enhanced the ability of Acacia species to escape being forced back by fire were also investigated. In all instances, the escape height varied among species with Acacia hockii escaping at the lowest height and Acacia polyacantha had the heighest escape height. In this study, the capacity for Acacia species to escape fire depended on the fire intensity, bark thickness, height and diameter of individual plants at the time of burning. Sprouts from Acacia sieberriana and Acacia gerrardii were most preferred by the browsers. Although the incidence of herbivory decreased with increase in height of the sprouts, the position of the sprouts did not determine palatability of all Acacia species. Only sprouts from the base of Acacia sieberriana were browsed whereas for Acacia gerrardii all sprouts were browsed irrespective of the position. The study also showed that cutting down of Acacia species for charcoal burning and building poles was a major factor in determining the tree structure and the sprouts density. All individuals of the different species in the study area sprouted after cutting irrespective of the size class and the position of the sprouts was correlated to the size of the original tree. Small individuals sprouted at the base and as the size increased, the position of the sprouts changed. Burning of the stumps after cutting had more negative effects on Acacia gerrardii compared to other Acacia species where only individuals in 4.00- 4.99m height size class retained the capacity to sprout. Fire was also seen to increase the flowering capacity of the Acacia species. Acacia hockii had the shortest individuals flowering whereas Acacia polyacantha started flowering after attaining a height of 4m. There was a positive correlation (r = 0.974, n = 4, P < 0.05) between the minimum height of flowering and the maximum height an individual could attain. Sprouts from burning and or cutting treatments were also monitored for flowering and only sprouts of Acacia hockii were able to flower the next flowering season after treatment and produced more seeds.
The feeding ecology, ontogeny and larval feeding in Labeo Victorianus Boulenger 1901 (Pisces: Cyprinidae)

(Makerere University, 2009-06) Owori, Wadunde Akisoferi

Labeo victorianus was one of the most popular commercial fish of Lake Victoria highly cherished by all communities within the lake basin. The fish was over fished and by the early 1960s it had virtually disappeared from the catches of the lake. There has been growing interest by both biodiversity conservators and fish consumers to restore the population of Labeo victorianus. It was identified in the Lake Victoria Environmental Management Project (LVEMP) as one of the species for restoration. Several investigations were carried out in the current study to provide the scientific knowledge that will facilitate the domestication of Labeo victorianus as a way of restoring its declined population. Ripe L. victorianus broodstocks were collected from the spawning grounds and induced under culture conditions using fresh extracts of the pituitary gland of the mirror carp (Cyprinus carpio) following a method used by Hecht et al. (1997) for catfish. The ontogenetic developmental of its digestive system were noted to provide the knowledge required for designing its diets and larval feeding program. This information would facilitate commercial production for Labeo victorianus seed fro aquaculture. An experimental investigation of the most suitable larval diets for L. victorianus was also carried out. Several diet types ranging from zooplankton, phytoplankton and dry diet were tested as starter diets for L. victorianus larvae. Suitability of the diets was compared on the basis of survival and growth. In another part of the study, the structure of the digestive system of Labeo victorianus was studied with the aim of determining the functional adaptability to the feeding ecology. By comparing the results with adaptations of similar structures of fish species of known feeding ecology, inference was made on the feeding ecology of Labeo victorianus. Results of this work were expected to provide clues on the feeding habits of this fish. The last investigation analyzed the composition of the gut content of Labeo victorianus to provide a better understanding of the diets and feeding habits of this fish. The analyses were carried out on gut contents collected throughout an annual cycle to see if there was seasonality in the feeding habits. The gut contents were isolated by food type and organisms identified. They were quantified using both the point and the frequency of occurrence methods to determine their importance in the diets. Labeo victorianus larvae hatch out with undeveloped digestive system and unable to start feeding. They rely on the yolk sac for at least 3 days before they area able to start feeding, although the yolk sac lasts up to 5 days. Therefore, feeding of the larvae can not start until 3 days post hatch. By Time 2 (T2), the mass of larvae was significantly higher in fish fed on either cladocerans or a combination of cladocerans and dry feed (Scheffe post-hoc tests, P < 0.05) (Fig. 2.9). Fish fed cladocerans exhibited the second highest mass, but it was not significantly greater (p > 0.5) than the dry feed or rotifer treatments. Survival was lower (P < 0.5) for L. victorianus larvae supplied with micro-algae than those supplied with either zooplankton alone or a combination of zooplankton and microalgae soon after the onset of exogenous feeding (at day 20). The fish fed on zooplankton exhibited a significantly higher mass than fish fed on micro-algae and the combination (Scheffe post hoc tests, P < 0.05). By this time survivorship in the dry feed treatment (70±6.0% of the original number) was lower than in the other three food treatments (posthoc tests, P < 0.05), but there was no difference in survivorship among the cladoceran, rotifer, and cladoceran/dry feed combination (88.7±9.0%, 86±9.2% and 91±7.8% of their original numbers, respectively) (post-hoc tests, P > 0.05). It was concluded that cladocerans and a combination of dry diet were the most suitable starter diets for L. victorianus larvae. The R. Sio and R. Kagera populations of L. victorianus did not differ significantly (p > 0.001) in all the morphotypes investigated, meaning that these two populations are very similar in their feeding adaptation. However, in the morphotypes that determine the normal position in the water column, L. victorianus was less (P < 0.5) adapted for benthic habitat than (C. gariepinus and B. docmak) but not as pelagic (p < 0.5) as the Nile tilapia. It was therefore concluded that L. victorianus was adapted for substrate habitats in relatively shallow waters. In its feeding ecology, all samples of L. victorianus collected at night (1900 hrs) and dawn (0500hrs) had empty guts. This indicates that this fish does not feed at night. This fish feeds on a diverse range of diet types ranging from detritus, plant parts, zooplankton, diatoms, and insect parts. By both the point and the frequency of occurrence methods the most dominant five items that were found in the guts of the R. Sio population were detritus, fine sand particles, cladocerans, Baciliophyta (diatoms), and Cyanophyta, in that order, and they contributed 84.6% of the gut content. The most dominant five items found in the guts of the R. Kagera population were detritus, fine sand, plant tissue, Chlorophyta, and Baciliophyta, in that order, and they contributed 90.5% of the gut content. In both of these cases there was no evidence of the nutritional value of sand, and it was concluded that it was probably ingested by accident during feeding on rocks. The most dominant diet types, that could be categorized as epiphytes, tend to grow on surfaces of objects (substrates). This finding suggests that L. victorianus could be grown on periphyton, such as the ‘acadja’ system. The implications of the findings of the current study for commercial aquaculture are discussed.
Role of Acacia and Erythrina trees in forest regeneration by vertebrate seed dispersers in grasslands of Kibale National Park, Uganda

(Makerere University, 2009-09) Kiwanuka, Majid

The central question of this study was ‘Do fire-resistant savanna trees such as Acacia sieberiana and Erythrina abyssinica and frugivorous vertebrates influence forest regeneration in the fire-prone grasslands of Kibale National Park, Uganda?’ In order to address the above question, seed rain and species richness and abundance of seedlings/saplings of forest trees were estimated both below and ten meters away from the crowns of these savanna trees for a period of six months (August 2007- March 2008). In addition, the rate of seed removal by seed predators in both areas below and ten meters away from crowns was estimated. Both areas, below and ten meters away from crowns, received seed rain and contained seedlings/saplings similar to those of the trees in the nearby forest. Species richness and abundance were significantly higher below than ten meters away from the crowns. However this was not the case with regards to seed rain. Although distance from the forest edge had a negative influence on species richness and abundance of seedlings/saplings, crown sizes of savanna trees had a positive influence. It was also found that there was no significant correlation between seed rain and distance from the forest edge. Furthermore the rate of seed removal by seed predators below and ten meters away from the crowns of savanna trees was not significantly different. The results from this study therefore demonstrate that forest regeneration is possible below the crowns of Acacia sieberiana and Erythrina abyssinica trees in the grasslands of Kibale National park. Key words: frugivorous vertebrates, seed rain, savanna trees, seed dispersal, seed predation, forest regeneration.
The prevalence of Crustacean parasities on Nile Perch (Lates niloticus) and Nile Tilapia (Oreochromis niloticus) in Lake Kyoga, Uganda.

(Makerere University, 2009-09) Mutaaye, Stephen

A study to investigate the prevalence and distribution of crustacean ectoparasites on the commercial fish species, Nile perch and Nile tilapia in Lake Kyoga, Uganda, was conducted through a survey for six months starting from February 2007 and ending July 2007. Crustacean ectoparasites are common parasites of fresh water fish and are known to cause detrimental effects to their hosts. Therefore the study particularly sought to provide information on the identity and intensity of the crustacean parasites infesting major commercial fish from Lake Kyoga of which little has been done and documented. Data was collected from inshore and offshore of each of the following sampling stations: Iyingo, Bukungu and Lwampanga once a month. A total of one thousand two hundred and seventy (1270) fish were sampled and examined for copepod ectoparasite. Six hundred and twenty nine (629) fish were Nile tilapia and six hundred forty one (641) were Nile perch. The findings showed that Oreochromis niloticus from Lake Kyoga was highly infested by crustacean ectoparasites of genus Lernaea and insignificantly infested with Dolops spp. However, Nile perch was found free of those parasites. The Lernaea parasites mostly occurred on the skin surface and rarely found on the inner lining of the operculum, gills and fins. Generally, incidence and intensity of infestation increased with size of the host. Size class of 30 - 34.9 cm (TL) was found to be the most infested followed by size class 25 - 29.9 cm (TL). Immature fish (juveniles) were free from any ectoparasite. There was no significant difference in the levels of infestation between the fish samples taken from inshore and offshore waters, different sampling stations or in different sexes. The study concluded that there was high parasite infestation of fish in Lake Kyoga where Oreochromis niloticus was mostly infested with crustacean ectoparasite, Lernaea sp. The level of infestation was comparable in both sexes of fish. The study recommends that the level of infestation by Lernaea and Dolops on fish in Kyoga be monitored and environmental friendly measures be adopted to control incidence of the parasites in the lake. It also recommends that the effects of these crustaceans on fish and on public health be investigated.
Biogeographical examination of the butterfly fauna in selected West Albertine Rift Forests

(Makerere University, 2009-09) Kasangaki, P.

This study was conducted with the main aim of evaluating the factors that may influence butterfly species richness and distribution (i.e. forest size, altitude, forest disturbance, average rainfall, temperature and distance from the supposed Pleistocene refugium) in 17 West Albertine rift forests (WARF’s), Uganda. Butterflies which were collected by the Forest Department (now National Forests Authority, NFA) and preserved at the Makerere University Museum were used for this study. Relevant biodiversity reports prepared by the Forest Department were reviewed to gather information on the physical and environmental attributes of the forests. A list of 630 butterfly species was complied for the 17 forests. Cluster, Principal component, Canonical correspondence and regression analyses were done to relate and compare butterfly species richness among the forests in order to establish the relationship between the butterfly species richness and the environmental and physical variables. These analyses helped in identifying the most important variables influencing the butterfly species richness and distribution in the forests. Forests with similar physical and environmental conditions had similar species richness. The environmental and physical variables which seemed to influence the species richness and distribution in the forests were forest size, number of plant species, altitude and levels of forests disturbance. Plant species richness appeared to be the most significant factor accounting for 49% of the butterfly species richness in the forests. Distance from the supposed Pleistocene refugium also seemed to have been responsible for species richness in the forests although not significantly. However, more research/survey should be done to involve population analysis (number of individuals other than only the number of species should be recorded) to ascertain the effect of forest disturbance on the butterfly species richness and population densities.
Habitat utilization and reproductive biology of Nile Tilapia (Oreochromis Niloticus) in Albert Nile, Nebbi District

(Makerere University, 2009-12) Nyakuni, Liverious

Some aspects of habitat utilization (distribution, abundance, size classes, condition factor) and reproductive biology (sex ratio, size at first maturity, fecundity) of O. niloticus were examined in Albert Nile in Nebbi District between January and July 2007 with an aim to understand the extent of habitat utilization and reproductive potential of the species among habitat types of Albert Nile. A total of 596 fish samples were collected from four major habitat types namely Vossia cuspidata, Eichhornia crassipes, Phragmites mauritianus dominated shores and open water areas using experimental gill nets of mesh size range 37.5mm to 125mm and small seine net operated from a boat or beach. The study established that the inshore areas of Albert Nile were characterized by diverse habitat types ranging from open water areas to various vegetation types (V. cuspidata, E. crassipes, and P. mauritianus) that provided suitable habitats for fish. The habitats were further characterized by shallow, slow flowing, warm water of average temperature 28.4ºC, and high dissolved oxygen with mean concentration of 6.4 mg/l, and pH oscillating around neutral value (7.04) which makes it suitable environment for fish habitation. Oreochromis niloticus was found in all habitat types but the relative abundance varied among habitats with highest number recorded in V. cuspidata (35.1%) followed by open water (27.5%) and the least in P. mauritianus habitat (14.9%). The mean length of O. niloticus captured in all the habitat types in Albert Nile was 16.4 cm TL. High abundance of juveniles of sizes ≤ 20 cm TL were found in V. cuspidata and E. crassipes habitats while mature individuals were more abundant in the open waters, indicating the importance of macrophytes as critical habitats for fish breeding, nursery grounds and providing shelter for protection against enemies. The condition factor (K) for O. niloticus in all the habitat types varied from 1.56 to 2.48 and the differences among habitats were significant (F= 6.4312, p < 0.05) with highest mean value among fish from open water (K= 2.19) and least in V. cuspidata (K= 1.92) which indicates that the habitats occupied by O. niloticus were not the same in terms of food availability, seasonality and other environmental factors that support fish life. Sex ratios were different among habitat types but in V. cuspidata and E. crassipes the differences from the hypothetical 1:1 were significant (χ2 = 4.36, p < 0.05 & χ2 = 3.18, p < 0.05 respectively). The overall sex ratio (male: female) of the pooled population of O. niloticus in this part of Albert Nile was 1:1.29 which was not significantly different from the hypothetical 1:1 (χ2 = 7.42, p < 0.05) but generally females were more abundant than males in the study area which is a good indication of high potential for replacement of stocks and sustainability of the fisheries resources in the river. The mean length at first maturity was 22.4 cm and 23.0 cm TL in females and males respectively while the number of eggs produced per female ranged from 412 to 2380 and the overall mean fecundity was 854 eggs per fish. The relationships of fecundity with body length and body weight were found to be linear and increasing with increasing fish length and body weight. Fecundity correlated more closely with body length (r = 0.88, p < 0.01) than body weight (r = 0.73, p < 0.01) but in both cases the relationship was significant (p < 0.01).
Discovery and verification of osteopontin and Beta-2-microglobulin as promising markers for staging Human African Trypanosomiasis

(The American Society for Biochemistry and Molecular Biology, 2010) Matovu, Enock ; Enyaru, John ; Tiberti, Natalia,

Human African trypanosomiasis, or sleeping sickness, is a parasitic disease endemic in sub-Saharan Africa, transmitted to humans through the bite of a tsetse fly. The first or hemolymphatic stage of the disease is associated with presence of parasites in the bloodstream, lymphatic system, and body tissues. If patients are left untreated, parasites cross the blood-brain barrier and invade the cerebrospinal fluid and the brain parenchyma, giving rise to the second or meningoencephalitic stage. Stage determination is a crucial step in guiding the choice of treatment, as drugs used for S2 are potentially dangerous. Current staging methods, based on counting white blood cells and demonstrating trypanosomes in cerebrospinal fluid, lack specificity and/or sensitivity. In the present study, we used several proteomic strategies to discover new markers with potential for staging human African trypanosomiasis. Cerebrospinal fluid (CSF) samples were collected from patients infected with Trypanosoma brucei gambiense in the Democratic Republic of Congo. The stage was determined following the guidelines of the national control program. The proteome of the samples was analyzed by two-dimensional gel electrophoresis (n= 9), and by sixplex tandem mass tag (TMT) isobaric labeling (n= 6) quantitative mass spectrometry. Overall, 73 proteins were overexpressed in patients presenting the second stage of the disease. Two of these, osteopontin and β-2-microglobulin, were confirmed to be potential markers for staging human African trypanosomiasis (HAT) by Western blot and ELISA. The two proteins significantly discriminated between S1 and S2 patients with high sensitivity (68% and 78%, respectively) for 100% specificity, and a combination of both improved the sensitivity to 91%. The levels of osteopontin and β-2-microglobulin in CSF of S2 patients (µg/ml range), as well as the fold increased concentration in S2 compared with S1 (3.8 and 5.5 respectively) make the two markers good candidates for the development of a test for staging HAT patients.
Some pharmacological activities of selected medicinal plant species used for treating cattle diseases in Kabira Sub-County, Rakai District

(Makerere University, 2010-03) Kamoga, Dennis

The study was undertaken with an overall objective of investigating use of medicinal plants in traditional management of cattle conditions / diseases with emphasis on helminthiasis and bacterial related infections in Kabira Sub-county, Rakai district. Life forms of the medicinal plant species, habitats of harvest and levels of harvest were observed and recorded. With respect to the overall objective, prioritization of key medicinal plant species as used in managing both helminthiasis and bacterial related infections was done using Participatory pair wise ranking technique. Methanolic extracts of priority medicinal plants that were tested in-vitro against helminthiasis (Ascaris suum) and bacterial related infections showed the following results. Among the four tested medicinal plant extracts, against A. suum, Clerodendrum rotundifolium Oliv. and Carissa edulis (Forssk.) Vahl. showed biological activity of more than 50% mortality rate at concentration of 1.2 mg/ml and 1.6 mg/ml respectively. The percentage mortality rates were 1 to 3 times higher compared to extracts of Myrica kandtiana Engl. and Erythrina abyssinica Lam. ex D.C. At intervals of 36 hours and 48 hours, C. edulis had the greatest percentage mortality rate overall, followed by C. rotundifolium. E. abyssinica had the lowest activity at 36 hours. However, both M. kandtiana and E. abyssinica showed comparably similar mortality rates at 48 hours for concentration of 1.2 mg/ml and 1.6 mg/ml. Variability in percentage mortality rates for the two medicinal plants was observed at concentration of 0.8 mg/ml, where Myrica kandtiana had a mortality rate one time higher than of E. abyssinica at both 36 hours and 48 hours. The standard drug (albendazole), had a higher percentage mortality rate of 12.5% against C.edulis and C .rotundifolium at 0.8 mg/ml at both 36 hours and 48 hours. At 1.2 mg/ml (albendazole) and C. edulis had similar mortality, while for C. rotundifolium mortality of less than 12.5% compared to albendazole was observed at 48 hours. At 1.6 mg/ml, albendazole, C. rotundifolium and Myrica kandtiana had 100% mortality at 36 hours and 48 hours, while for C.edulis and E.abyssinica less than 12.5% mortality was observed compared to albendazole at 36 hours interval. All the three bacterial species were susceptible to only four methanolic extracts of M.kandtiana, Entada abyssinica Steud ex D.C, Rubus steudneri Schweinf. and Solanum aculeastrum Dunal. Staphylococcus aureus and Escherichia coli were susceptible to Sesamum anguistifolium (Oliv.) Engl. and Sapium ellipticum (Hoscht.) Pax., while restricted activity to Staphylococcus aureus was observed with Erythrina abyssinica. Overall, Rubus steudneri showed the highest level of susceptibility, followed by Entada abyssinica and then Myrica kandtiana, Sesamum anguistifolium and Erythrina abyssinica had the least activity. Comparison of the standard drug (gentamycin) with methanolic extracts of all the seven medicinal plant species, only showed relatively similar levels of susceptibility with Rubus steudneri. Overall Rubus steudneri and Erythrina abyssinica had the lowest MIC values, 0.03125 µg/ml similar to that of the standard drug (gentamycin). Thus, the two methanolic extracts had the highest biological activity against Staphylococcus aureus and Pseudomonas auroginosa. Consequently Myrica kandtiana and Entada abyssinica had MIC value of 0.0625 µg/ml against Staphylococcus aureus and Pseudomonas auroginosa. With 0.0625 µg/ml which was the second least concentration to 0.03125 µg/ml for the standard drug, Myrica kandtiana, Entada abyssinica, Rubus steudneri and Erythrina abyssinica were more potent compared to the medicinal plant abyssinica extracts of Solanum aculeastrum, Sesamum anguistifolium and Sapium ellipticum with high MIC values above 0.0625 µg/ml. For E.coli growth, 0.0625 µg/ml was observed as the least MIC for Myrica kandtiana, Solanum aculeastrum, Sesamum anguistifolium and Sapium, an indication that the four plant extracts had the highest activity against this test bacterium. The in-vitro studies of methanolic extracts of the selected medicinal plant species on Ascaris suum and the three species of bacteria were conducted as a preliminary proof to support their use in traditional management of both helminthiasis and bacterial related infections.
An ecogeographical study and genetic variation of the genus eulophia in selected wetlands of Uganda

(Makerere University, 2010-10) Mbeiza, Mutekanga Norah

The study was carried out in some freshwater emergent reed swamps typically dominated by a single reed species and seasonally flooded herbaceous wetlands whose vegetation composition was variable. These were the Kafu River valley, Lake Nabugabo wetlands, Sezibwa river system, Namanve swamp, Lake Victoria wetlands, Lake Mulehe, Lake Mutanda, Kyaka wetlands and Lake Kyoga wetlands. For the genus Eulophia, information on its ecology, geography is limited and was especially lacking for wetlands in Uganda. The lack of this knowledge makes it difficult and in most cases impossible for effective conservation to be proposed and later implemented. The objectives of the study were to determine Eulophia’s diversity, distribution and nature of habitats where they thrive; genetic variation within this genus and establish dangers and risks faced by Eulophia in wetlands in Uganda. Transects, and searching around on time basis for individual plants; atomic absorption spectrophotometry for exchangeable and inexchangeable bases in the soils were used. Available data from the herbarium collections and available data was used to generate the checklist of this genus. In addition, Amplified Fragment length Polymorphism (AFLP) procedure was followed for genetic variation and NTSYSpc 2.01 software used in analysis. Eulophia were found to be widely distributed in Uganda though their current status in the entire nation needs to be reassessed considering the fact that some were last recorded over 50 years ago (thought extinct). Thirty species are known to occur in Uganda and their distribution shown on a map. Eight of these species were considered in this study. This study has established that most occurrences of Eulophia are small consisting of scattered individuals and the human activities that occur in the species’ habitats negatively affect individuals and/or occurrences. There was no significant relationship between edaphic factors and diversity and distribution of Eulophia. It was also established that genetic diversity occurs both within and between sites. AFLP’s distinguished between the individuals. In this cluster analysis of genetic similarities all individuals (100%) were arranged in population (site) specific clusters. Overall representation of relationships among individuals by cluster analysis and ordination was in agreement. This study therefore, comes up with information for monitoring; identifies areas of Eulophia species richness and identifies genetic variation within the genus; it also points at types of threats to Eulophia in wetlands in Uganda and proposes conservation needs.
Evaluating the effectiveness of botanicals locally used in tick control amongst the cattle keeping communities of Northern Uganda Districts of Gulu and Amuru

(Makerere University, 2010-12) Opiro, Robert

This research work aimed at documenting and evaluating the effectiveness of botanicals locally used in tick control amongst the cattle keeping communities of northern Uganda districts of Gulu and Amuru. The documentation of the botanicals was accomplished by carrying out guided interviews with the cattle keepers on their knowledge of ethnobotanicals used for tick control. The interviewees were selected purposively (25 years and above only) but irrespective of gender. Information on local names, methods of preparation and administration of the plant products were captured. A total of 13 plant species belonging to 8 families were documented as locally perceived to control ticks. Of these, 4 plants that were most commonly cited by the cattle keepers for tick control were subsequently selected for evaluation of tick mortality and repellence in the laboratory bioassays. The plant extracts were evaluated for tick mortality responses using FAO Stone Packet Technique where Whartman® filter paper packets were impregnated with the extracts and distilled water for treatment and control groups, respectively. The repellence effects were investigated by the fingertip bioassay. The results showed that the best performing plant species, in order of decreasing efficacies, were Cassia didymobotrya, Kigelia africana, Cissus adenocucaulis and Euphorbia hirta. The factors associated with the death of the ticks included plant species, duration of exposure to test extracts and concentrations. The lethal concentration (LC) values of the plant extracts decreased with the duration of exposure. The study also demonstrated that all plant extracts evaluated showed repellence effects, with Cassia didymobotrya and Kigelia africana providing the best repellence percentages of 76-88%. This revealed the unexploited potential of these plants for tick control that can be integrated with other tick management systems for use by the resource-poor livestock farmers in northern Uganda.
Dithiocarbamate residue levels in selected vegetables from Bukavu Region, Democratic Republic of Congo

( 2011-03) Muyisa, Kavatsurwa

This study involved a survey on the use of dithiocarbamates in agriculture practices in Bukavu Region and the determination of their residues in vegetables (tomatoes and cabbages) from five main sites supplying Bukavu town with vegetables. The survey revealed that mancozeb, traded under the name of Dithan-45 was the main dithiocarbamate widely used, especially in the tomato crops against pests. It was also realised that farmers were not well trained in how to handle the pesticide and as a result, they were not informed of any consequence that could result from the misuse or the mishandling of mancozeb. Analytical method based on HPLC-UV, developed by Codex Committee on pesticide residues was employed for the analysis of mancozeb residues from vegetables samples (tomatoes and cabbages) collected from Bukavu region in DRC. A total of 75 vegetable samples were collected from different fields of five main sites known to supply Bukavu town with vegetables. The laboratory analysis showed a Limit of Detection of 0.01 mg/kg, the recoveries ranged from 73.5 to 82.1 % for cabbages and 64.0 to 66.9 % for tomatoes. The concentration of the residues expressed as mancozeb (the factor conversion for mancozeb derivative = 1.13) in tomatoes varied (in mg/ kg) from no detectable values (ND) to 1.33 for Kamanyola, ND to 1.87 for Nyangezi, 1.44 to 3.99 for Katana, 1.54 to 4.06 for Miti and ND to 4.65 for Mudaka samples. The average values ± SD (Standard Deviation) in mg/ kg for the five study sites were 0.89 ± 0.35, 1.31 ± 0.44, 2.48 ± 1.02, 2.71 ± 0.82 and 3.25 ± 1.25 respectively. The results further show that 24 % of the tomato samples had mancozeb residue values above the MRLs of European Food Safety Authority and 33 % above the MRLs set by EPA, while 73 % were not good for consumption with regards to the maximum permitted level for dithiocarbamates in tomatoes (1 mg/ kg) in Germany. On the other hand, 83% of cabbage samples from all sites had no detectable mancozeb residue levels and the rest had less than 0.1 mg/ kg.
Determining the prevalence of Trichomonas Vaginalis as a possible marker of inconsistent in condom use

(Makerere University, 2011-05) Ojiambo, Henry

A cross sectional study was carried out at Assessment Center, based at Mulago Hospital, to determine the prevalence of Trichomonas vaginalis as a possible marker of inconsistent condom use among individuals. Its’ specific objectives were to: - determine the knowledge gaps, attitudes and beliefs of the community about condom use, determine the relative prevalence of Trichomonas vaginalis among persons who do not use condoms and those who use condoms consistently. One hundred participants aged 15-63 were enrolled in the study. A structured questionnaire was used to capture the data from the participants on the knowledge gap, attitude and beliefs about condom use. Each participant was asked to produce urine for Trichomonas vaginalis culture using InpouchTV. Each pouch was examined at 24 h, 48 h for 3 days. All the participants were aware of condom although 28% did not know how to use them. Seventy two percent (72%) claimed that they knew how to use condoms. Twenty percent (20%)of the participants with informal education claimed to know how to use a condom compared to 62.5% with primary education, 89.7% and 90.5% with secondary and tertiary education respectively (p<0.05). About 28% and 18% of the participants had positive and negative attitude towards condom use respectively. Others had neither positive nor negative attitude towards condom use. Seventy seven percent (77%) of the participants thought that condom limits sexual satisfaction and 62% thought that condom had a bad smell. Nine percent (9%) believed that condom can tear and remain in the vagina. Others believed that condom can cause pain (61%), leads to bleeding (55%) and prevents STI/HIV (73%). Sixty six percent (66%) of the patients had had one sexual partner, while 16% had had more than two sexual partners during the time of the study. Nine of the participants had consistently used condom compared to 76 participants who had not used condom at all (p < 0.001). The prevalence of Trichomonas vaginalis was found to be 8%. Six females and 2 males were infected with T. vaginalis. Of those that did not use condom, 8 participants had Trichomonas vaginalis while none of the participants who used condom consistently had Trichomonas vaginalis (p>0.05). In conclusion the majority of the participants did not use condom although they were aware and knew how to use them. Trichomonas vaginalis is still a health problem in the communities. This study therefore recommends for more aggressive sensitization programmes to be put in place to sensitize communities about condom use and its associated benefits. Since the study involved a small sample, bigger studies should be carried out in the country.
Phenetic, distribution and genetic structure of Acacia Senegal (L.) Willd in Uganda.

(Makerere University, 2011-05) Mulumba, Waswa John

The overall objective of the study was to evaluate the diversity and distribution of Acacia senegal in Uganda. The wide variation in Acacia senegal has presented taxonomic uncertainties and unresolved contradictions in previous studies. In this study numerical taxonomic principles and multivariate analysis (UPGMA PCoA, and PCA) were used basing on 69 characters derived from growth form, branchlets, leaves, flowers, pods and seed. Three taxa, namely; variety senegal, leiorhachis and kerensis have been discerned and described significantly improving the delimitations of previous studies. The wide variation within var. senegal has been split into three recognizable variants and that of var. leiorhachis into two. A field guide and a taxonomic key have been constructed making it possible to assign herbarium specimens to their respective taxa. The distribution of the infraspecific taxa was analysed for diversity, richness, turnover and reserve selection. Regression analysis was performed to understand the relationship between distribution of the species and climatic variables. Geo-referenced species occurrence points were superimposed over temperature and vapour maps. Areas with highest taxa diversity, richness, and turnover were mapped and found in the Lake Kyoga basin despite the highest species population density occurring in Karamaoja area. The species shows preference for the northern region of the cattle corridor with dissimilar climatic pattern from the southern region and the superimposition supported findings. Variety kerensis exhibited narrower climatic, altitudinal and distribution range preference. Temperature seasonality, maximum temperature of warmest month, temperature annual range, mean temperatures of warmest and driest quarters had the highest coefficients of determination (r2>0.7) hence most important in influencing species distribution. The genetic variation and population structure of Acacia senegal was analysed at four microsatellite loci. All four loci were highly variable, with the number of alleles per locus ranging from 8 – 14 (mean = 10.5). Substantial levels of genetic diversity were found (mean expected heterozygosity, He = 0.479, range 0.245 – 0.846; Information Index, I = 0.927, range 0.646–1.206). Areas with higher genetic diversity corresponded with the areas with higher richness and diversity. Analysis of molecular variance demonstrated moderate genetic differentiation among populations [Fst = 0.100, P≤ 0.001], comparable to similar tropical species. Isolation by distance, based on Mantel Test showed a positive and significant correlation [Rxy = 0.197, P≤ 0.001]. Based on population assignment, pair-wise population comparisons and PCA, four populations emerged; one on the eastern and the other on the western side of Lake Kyoga, suggesting isolation due to a water body barrier; two other populations emerged in Karamoja. There was, however, no concordance between the infraspecific groupings and the populations. The observed southern-northern flowering pattern across the species distribution range appears central to the species differentiation. The most appropriate locations for in-situ conservation and for germplasm collection to ensure maximum diversity is secured are found in Wabisi- Wajala, Kiula, Kyalubanga, Bajo, Kasagala, Kabwika-mujwalanganda, Maruzi, Moroto and Napak Central Forest Reserves. The study recommends, among others, ecological studies to understand status of Acacia senegal. The results are presented in four publications (chapter four to seven).
Biochemical characterisation of water from River Ntabago and implication on water quality and safety

( 2011-05) Muhwezi, James

This study analysed the biological and chemical components characterising water from River Ntabago. The composition of the water determines its quality and affects the lives of aquatic organisms and other water consumers. The study was carried out from January to July 2009. Human activities such as brewing, farming, and washing fabrics; and natural processes like erosion, affect the biochemical composition of the water, its quality and people’s health. The water has a bad smell, bitter taste and contains black particles that make it look unpleasant. There are complaints of skin irritations and/or ulcerations when the water is used for bathing and abdominal pains when drunk. The objectives of this study were: to determine the phytoplankton composition of the water; to quantify heavy metals in water: cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel, zinc; and anions: chloride, fluoride, sulphate and sulphide. The study also determined water quality parameters: pH, temperature, specific conductance, dissolved oxygen, coliforms, alkalinity, turbidity, hardness, and nutrients; so as to assess the quality of the water and its safety as a source for domestic use. The biological parameters were determined using microcopy, heavy metals using atomic absorption spectrophotometry, while anions and water quality parameters were analysed using various titration and colorimetric methods. The study revealed the concentration of phytoplaktons to be very high and increasing downstream. These reduced water quality through production of: toxins, irritant lipo-polysaccharides, taste and odour substances; reduction of dissolved oxygen and increasing turbidity and colour of the water. Concentrations of coliform bacteria were fairly high. The study also revealed the existence of cadmium, iron, lead, manganese and nickel above their NEMA and WHO recommended values for potable and drinking water, raising concerns for the health of water consumers. The health effects of metals include: lowering energy levels; damaging the central nervous system and mental function; damaging blood composition, lungs, kidneys, liver and other vital organs. Turbidity and alkalinity were shown to be high, hardness fairly moderate, while dissolved oxygen and nutrients were very low in comparison to their recommended values. The biochemical composition and water quality of the river were functions of growing population pressure, changing settlement and development patterns, siltation due to loss of vegetation cover and land degradation, seasonal variations in rainfall, agricultural runoffs, water-flow fluctuation rates, heavy metal discharges from weathered rocks and wetland drainage. The water of River Ntabago is therefore considered unsuitable for human and livestock consumption because of high phytoplankton and heavy metal concentration, high turbidity, low dissolved oxygen and the presence of coliforms. Hence, there is need for: a watershed management program in the area, more research to be done, treatment of water in order to meet standards for potability, planning some alternative water, promotion public awareness and sustainability issues, proper land utilization and improved agricultural practices; frequent surveys and monitoring programs to ensure the quality of water.
Prevalence and control of tick-borne parasites of domestic ruminants in different livestock production systems in Gulu District, Uganda

(Makerere University, 2011-06) Angwech, Harriet

The study assessed the prevalence of tick-borne parasites in domestic ruminants in relation to the control and / or management practices applied by farmers against ticks and TBDs in Gulu District, Uganda. Blood smears were made from 552 domestic ruminants (cattle, sheep and goats) under open grazing, tethering and zero-grazing systems to determine the prevalence of tick-borne parasites from January to March, 2008. The significance of the relationships between prevalence of tick-borne parasites and management system, ruminant type and sex of the animal were analyzed using one-way analysis of variance and Fisher Least Significant Difference. In the study the following three tick-borne parasites were found infecting domestic ruminants in zero-grazing, tethering and open grazing systems: Theileria, Anaplasma and Babesia. The most prevalent tick-borne parasites were Theileria and Anaplasma. The prevalence of the three tick-borne parasites also varied significantly by grazing systems. There was no significant difference in the prevalence rate by ruminant type and sex of animals under study (P = 0.05). The study also revealed that there was no significant difference between zero-grazing and tethering systems (P = 0.05). Ruminants raised under open grazing were more likely to have increased risk of contracting the parasites compared to their counterparts under tethering and zero-grazing, respectively. Management of ticks and tick-borne parasites was more intensive in zero-grazed farms than in the other systems. It was therefore recommended that farmers in the study area use tethering system which is less costly compared to zero-grazing since it reduces the prevalence of Theileria, Babesia and Anaplasma.
The ecology of enteric bacterial transmission among apes, humans, and livestock in Bwindi Impenetrable and Kibale National Parks, Uganda

(Makerere University, 2011-11) Rwego, Innocent B.

The problem of disease transmission between apes and humans has been a subject of great concern, but few studies have examined this from an ecological perspective, or confirmed transmission using genetic methods. The main goal of this thesis was to understand how and why ape anthroponoses and zoonoses emerge in tropical forest ecosystems and to suggest control measures that can be put into place to stop the spread of such infections. In order to achieve this, one hundred and forty households in the study area in and around Bwindi Impenetrable and Kibale National Parks were surveyed about their demographics, health, and interaction with wild primates. At the same time fecal samples were collected from humans, domestic animals and apes to isolate Escherichia coli, a common bacterium, which were then genotyped using a “DNA fingerprinting” method. Data were used to examine whether habitat overlap influences rates and patterns of bacterial transmission among humans, domestic animals and apes. Findings indicate that gorilla populations that frequently interact with people and domestic animals harbor E. coli bacteria that are genetically similar to those from the people or domestic animals with which they interact. On the other hand, gorilla populations with limited interaction with humans harbor E. coli bacteria more genetically distant from those of local people. Additionally, antibiotic resistance was high in bacteria from humans, lower in bacteria from domestic animals, and lowest in bacteria from mountain gorillas; within gorillas, groups with no or little overlap with humans harbored bacteria with the lowest levels of resistance. Genetic distances between human and livestock bacteria were generally very low, indicating high rates of bacterial gene flow between humans and their domestic animals. Data showed that people who did not regularly wash their hands before eating harbored bacteria approximately twice as similar genetically to bacteria of their livestock as did people who regularly washed their hands before eating. Furthermore, findings indicate that crop raiding is contributing to pathogen transmission between apes and humans and domestic livestock in Bwindi. People and livestock from Bwindi tended to harbor E. coli bacteria more similar to those of crop-raiding gorillas with “high overlap” than to bacteria from “low overlap” gorillas that do not raid crops. This pattern was, however, different for Kibale, where humans and their livestock living near Kibale harbored bacteria that were genetically similar to those from chimpanzees at a remote location and with “low overlap,” but less similar to bacteria from local “high overlap” chimpanzees. The reasons for this paradoxical result in Kibale are unclear, but may have to do with patterns of water flow. Although almost all animals in the two locations contributed to crop raiding, the role of this practice in pathogen transmission was only examined in apes. In both Bwindi and Kibale, primates (most often baboons) were responsible for the majority of crop raiding events, followed by bush pigs. Apes (chimpanzees and mountain gorillas) were not highly implicated in the crop raiding events, with apes mainly targeting banana plantations. Patterns of genetic similarity and antibiotic resistance among E. coli from populations of apes, humans, and livestock indicate that habitat overlap between species affects the dynamics of gastrointestinal bacterial transmission, perhaps through domestic animal intermediates and the physical environment; and that patterns of human hygiene affect human-livestock bacterial transmission in rural settings. Limiting transmission would benefit human and domestic animal health and ape conservation. These results highlight not only the potential importance of crop-raiding as a factor increasing infectious disease transmission risk between apes and people in areas of human-ape conflict, but also the variability of this trend among locations.

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