Faculty of Science (FSC)

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Open Access
A Revised Protecting Group Strategy Enables a Divergent Synthesis of Prenylated Isoflavones from Psoralea corylifolia
(Synthesis, 2025) Gliszczinskia Sarah von Chamier; Sperlicha Eric; Kellinga Alexandra; Kwesiga George; Schmidt Bernd
Three bioactive prenylated isoflavone natural products were synthesized for the first time, using a combination of Pd-catalyzed Suzuki–Miyaura coupling for installing the B-ring, microwave-promoted Claisen rearrangement of allyl ethers, and Ru-catalyzed olefin cross me tathesis for obtaining the prenyl substituents. Careful consideration of the protecting group strategy turned out to be vital for the success of these total syntheses.
Open Access
Low Latitude Analysis of Geomagnetic Storm Effects on Ionospheric Vertical Drifts over the East African Region
(Atmospheric and Climate Sciences, 2025) Niwamanya, Duncan; Habyarimana , Valence; Jurua, Edward
The geomagnetic storm effect on ionospheric vertical E × B drift is analysed using Communication/Navigation Outage and Forecasting System (C/NOFS) Satellite data, magnetometer data, and solar wind data, over the East African low latitude region during the period 2008-2015. We identified a total of 608 corotating interaction region (CIR)-driven and 23 coronal mass ejection (CME)-driven geomagnetic storms in this study. Most of the CIR-driven storms were observed during the declining phase of solar cycle 24 in 2015. The CME-driven storms, on the other hand, were dominant during the near maximum phase of the solar cycle 24 in 2012. The C/NOFS satellite data was found to be consistent with magnetometer observations in identifying both upward and downward vertical E × B drift occurrence. The common result of analysed CME-driven geomagnetic storms was enhancement in E × B drifts due to presence of eastward prompt penetrating electric fields (PPEFs) during the storm main phase. There was also a decrease in E × B due to the decrease in horizontal component of the magnetic field ( ΔH ) during the recovery phases of the CME-driven storms. This is a manifestation of downward E × B drifts associated with westward electric field, which is due to the disturbance dynamo contribution. During CIR-driven geomagnetic storms, the storm’s main phases were also dominated by downward E × B drifts associated with westward electric field, which is due to disturbance dynamo.
Open Access
A systematic review of Aspilia africana (Pers.) C.D. adams traditional medicinal uses, phytoconstituents, bioactivities, and toxicities
(Elsevier, 2025) Gang, Roggers; Okello, Denis; Yeongjun, Ban; Kang, Youngmin
Aspilia africana (Pers.) C. D. Adams, popularly referred to as wild sunflower, has been used for generations across several African communities to treat various diseases, including malaria, wounds, osteoporosis, diabetes mellitus, gastric ulcers, measles, tuberculosis, stomach ache, rheumatic pains, and gonorrhea. This study aimed to sys-tematically and critically compile data on the traditional medicinal uses, phytochemistry, bioactivities, botanical descriptions, and toxicities of A. africana. Relevant research findings were retrieved and organized from various databases, including PubMed and ScienceDirect, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. To date, 149 phytochemicals have been identified from various A. africana parts and they primarily belong to the classes of terpenoids, lipids, hydrocarbons, phenolics, and esters. The extracts and bioactive phytochemicals of A. africana have revealed several pharmacological prop-erties, including antimalarial, anticancer, wound healing, anti-inflammatory, antidiabetic, and antimicrobial activities. However, the major components responsible for these bioactivities and their mechanisms of action in some diseases have not yet been clearly identified. Additionally, toxicity and clinical trial data for A. africana are limited with most toxicological assessments being acute in nature. Therefore, further research on the mechanisms of action of the pure bioactive phytochemicals and toxicity of A. africana are necessary to better understand its efficacy and safety. Taken together, this study provides comprehensive information on the traditional medicinal uses, phytochemistry, bioactivities, and toxicity of A. africana, and a reference for future studies, relevant to the development of therapeutic products.
Open Access
Antibacterial Properties of Phytochemicals Isolated from Leaves of Alstonia boonei and Aerial Parts of Ipomoea cairica.
(Kabale University, 2024) Gumula, Ivan; Kyarimpa, Christine; Nanyonga, Sarah Kiwanuka; Kwesiga, George; Busulwa, George; Opio, Boniface; Heydenreich, Mathias; Omara, Timothy
The leaves of Alstonia boonei and aerial parts of Ipomoea cairica are used for treatment of microbial infections among other ailments in African traditional medicine. The aim of this study was to investigate the antimicrobial phytochemicals in A. boonei leaves and Ipomoea cairica aerial parts to validate their traditional use in Ugandan herbal medicine. Methods: The plant materials were separately extracted using a dichloromethane/methanol (1:1) solvent system and subjected to repeated chromatographic separation to isolate pure compounds. The chemical structures of the isolated compounds were determined through 1 H NMR, 13C NMR and 2D NMR (COSY, HSQC and HMBC). The antibacterial activity of the extracts and pure compounds were assessed using the agar well diffusion method. Results: Chromatographic fractionation of the extracts yielded trans-fagaramide and a pentacyclic lupane-type triterpenoid, lupeol, from A. boonei, and friedelin from I. cairica. Trans-fagaramide was identified for the first time in the Alstonia genus while friedelin was identified for the first time in I. cairica. The isolated compounds demonstrated antibacterial activity, with trans-fagaramide showing a minimum inhibitory concentration (MIC) of 125 μg/mL against Pseudomonas aeruginosa and 250 μg/mL against Staphylococcus aureus, Salmonella typhi and Escherichia coli. Friedelin exhibited a MIC of 125 μg/mL against Escherichia coli and 250 μg/mL against Pseudomonas aeruginosa, Staphylococcus aureus and Salmonella typhi. Conclusion: The antibacterial activities observed in this study support the traditional use of A. boonei and I. cairica by indigenous communities in Uganda for treating microbial infections.
Open Access
Determining Bandgap of Thermochromic Phosphor Films via Reflectance Measurements under Controlled Heating
(Kabale University, 2024) Katashaya, Steven Rwabona
In this article, we present a method to determine the bandgap of a thermochromic phosphor film by simple reflectance measurements under controlled heating. The phosphor is illuminated by a light-emitting diode while being heated continuously. The reflected light is detected using a calibrated photodiode circuit based on an operational transconductance amplifier. We apply the Schuster Kubelka-Munk function to deduce the absorbance over temperature and thus the bandgap. We show, for the first time, that the thermochromic phosphor's color change follows Arrhenius's Law and therefore involves activation energy. We estimate the bandgap to be between 1.1 eV and 1.9 eV and find an activation energy of 46.67 ±1.6 kJ/mol. The simplicity of the approach will appeal to undergraduate teachers and students of physics and materials science. The technique can be used to investigate other thermochromic materials as well.
Open Access
Medicinal Plants used for Cutaneous Wound Healing in Uganda; Ethnomedicinal Reports and Pharmacological Evidences.
(Kabale University, 2024) Gang, Roggers; Okello, Denis; Kang, Youngmin
Background: Wounds have become a major health challenge worldwide, presenting marked humanistic and economic burdens such as disabilities and death. Annually, approximately 14 million people suffer from wounds worldwide and 80 % of these occur in developing countries like Uganda. In Uganda, besides many cases of daily wound occurrences, approximately 10 % of surgical procedures become septic wounds and consequently lead to increased morbidity and mortality. Accordingly, several ethnomedicinal studies have identified plants used for wound treatment in different parts of Uganda and the wound-healing activities of some plants have been reported. However, at present, this information remain largely separated without an all- inclusive repository containing ethnomedicinal and pharmacological information about the plants used for wound healing in Uganda, thus retarding appropriate evaluation. Therefore, this review focused on extensively exploring the plants used for treating cutaneous wounds in Uganda, along with associated ethnomedicinal information and their globally reported pharmacological potential. Methods: Electronic data bases including Google Scholar, PubMed, and Science Direct were searched using key terms for required information contained in English peer reviewed articles, books, and dissertations. Additionally, correlations between selected parameters were determined with coefficient of determination (r2). Results: The literature survey revealed that 165 species belonging to 62 families are traditionally used to treat wounds in Uganda. Most of the species belonged to families of Asteraceae (14 %), Fabaceae (10 %), and Euphorbiaceae (7 %). The commonest plant parts used for wound treatment include leaf (48 %), root (22 %), stembark (11 %), and stem (7 %), which are prepared majorly by poultice (34 %), decoction (13 %), as well as powdering (25 %). Fifty-four (33 %) of the plant species have been investigated for their wound-healing activities whereas, one hundred eleven (67 %) have not been scientifically investigated for their wound-healing effects. Pearson correlation coefficient between the number of wound-healing plant families per part used and the percent of each plant part used was 0.97, and between the number of wound-healing plant families per method of preparation and percent of each method of preparation was 0.95, showing in both strong positively marked relationships.
Open Access
Agricultural sustainability through Smart Farming Systems: A comparative Analysis Between the Republic of Korea and Republic of Uganda.
(Kabale University, 2024) Happy, Kenneth; Gang, Roggers; Ban, Yeongjun; Yang, Sungyu; Rahmat, Endang; Okello, Denis; Komakech, Richard; Cyrus, Okello; Okello, Kalule David; Kang, Youngmin
Smart farming involves the integration of information and communication technologies into machinery and sensors for use in agricultural systems. It is expected to potentially enhance the sustainability of agriculture and global food security. The need for smart farming arises from the increasing adverse environmental, ecological, social, and economic impacts on food systems. The potential impact of smart farming solutions on different countries is less known. Therefore, we comprehensively analyzed the role of smart farming solutions in sustaining agricultural production in the context of comparing a developed (Republic of Korea), and an emergent (Republic of Uganda) country. We scrutinized the agricultural assets, natural resources, approaches, technologies, policy interventions, achievements, challenges encountered, and reasons of smart farm pursuit for each country. Information presented in the paper indicated that both countries have similar objectives in the pursuit for smart farming: response to climate change and sustaining food security. However, the Republic of Korea employs a holistic approach of revolutionizing agriculture via smart farms. In contrast, distinct smart farming interventions implemented by government institutions, competing private sector, and non-governmental organizations are shaping the development of a smart farm concept in the Republic of Uganda. In conclusion, the application of smart farming solutions appears to be promising in enhancing the stability of the whole food system in both countries.
Open Access
In vitro multiplication and phytochemical evaluation of Apios americana Medik for enhanced production of the staple food and tissues with versatile bioactivities.
(Kabale University, 2024) Okello, Denis; Gang, Roggers; Rahmat, Endang; Yang, Sungyu; Ban, Yeongjun; Chung, Yuseong; Lee, Jun; Kang, Youngmin
Apios americana Medik tissues, including tubers, flowers, leaves, and vines have both nutritional and therapeutic benefits. These tissues are extensively used in products like beverages and food supplements, driving an exponential increase in worldwide demand for the plant. However, conventional propagation of A. Americana through seeds and tubers faces several challenges, including limited seed sets under manual pollination, resulting in reduced production. To overcome these challenges, micropropagation emerges as a promising solution. The current research study has developed an effective in vitro propagation strategy for A. americana using direct regeneration from apical segment explants. Full-strength Quoirin and Lepoivre (QL) medium, supplemented with vitamins and 2.0 mg/L benzylaminopurine (BAP), yielded the highest number of shoots (7.50 ± 0.06) per apical segment explant. QL medium fortified with 1.0 mg/L indole-3-butyric acid (IBA) demonstrated the highest root number (2.80 ± 0.30), length (85.80 ± 7.49 mm), and surface area (10.40 ± 0.82 cm2) in regenerated A. American shoots. The survival rate of the regenerants in the ex-vitro environment was 92.7% after acclimatization. In vitro-regenerated A. Americana plants and mother plants exhibited similar ploidy levels, chlorophyll content, photosynthetic rate, phytochemical composition, and antioxidant capacity, indicating similarity in their physiological and biochemical properties. This protocol offers a rapid and scalable method for generating high-quality, A. Americana plant stocks with stable genome size/ploidy level, meeting the exponentially growing demand for plant tissues. Additionally, it holds potential applications in A. Americana breeding and germplasm preservation.
Open Access
Characterizing absolutely irreducible integer-valued polynomials over discrete valuation domains
(2024) Hiebler, Moritz; Nakato, Sarah; Rissner, Roswitha
Rings of integer-valued polynomials are known to be atomic, non-factorial rings furnishing examples for both irreducible elements for which all powers factor uniquely (absolutely irreducibles) and irreducible elements where some power has a factorization different from the trivial one. In this paper, we study irreducible polynomials F ∈ Int(R) where R is a discrete valuation domain with finite residue field and show that it is possible to explicitly determine a number S ∈ N that reduces the absolute irreducibility of F to the unique factorization of F S. To this end, we establish a connection between the factors of powers of F and the kernel of a certain linear map that we associate to F. This connection yields a characterization of absolute irreducibility in terms of this so-called fixed divisor kernel. Given a non-trivial element v of this kernel, we explicitly construct non-trivial factorizations of Fk, provided that k ≥ L, where L depends on F as well as the choice of v. We further show that this bound cannot be improved in general. Additionally, we provide other (larger) lower bounds
Open Access
Characterizing absolutely irreducible integer-valued polynomials over discrete valuation domains
(Journal of Algebra 633 (2023) 696–72, 2023-08-12) Hiebler, Moritz; Nakato, Sarah; Roswitha,Rissner
Rings of integer-valued polynomials are known to be atomic, non-factorial rings furnishing examples for both irreducible elements for which all powers factor uniquely (absolutely irreducibles) and irreducible elements where some power has a factorization different from the trivial one. In this paper, we study irreducible polynomials F ∈ Int(R) where R is a discrete valuation domain with finite residue field and show that it is possible to explicitly determine a number S ∈ N that reduces the absolute irreducibility of F to the unique factorization of F S . To this end, we establish a connection between the factors of powers of F and the kernel of a certain linear map that we associate to F . This connection yields a characterization of absolute irreducibility in terms of this so-called fixed divisor kernel. Given a non-trivial element v of this kernel, we explicitly construct non-trivial factorizations of F k , provided that k ≥ L, where L depends on F as well as the choice of v. We further show that this bound cannot be improved in general. Additionally, we provide other (larger) lower bounds for k, one of which only depends on the valuation of the denominator of F and the size of the residue class field of R.
Open Access
Conservation of forest biomass and forest–dependent wildlife population: Uncertainty quantification of the model parameters
(Heliyon, 2023-07-06) Ibrahim, M. Fanuel; Silas, Mirau; Damian, Kajunguri; Francis, Moyo
The ecosystem is confronted with numerous challenges as a consequence of the escalating human population and its corresponding activities. Among these challenges lies the degradation of forest biomass, which directly contributes to a reduction in forested areas and poses a significant threat to the survival of wildlife species through the intensification of intraspecific competition. In this paper, a non–linear mathematical model to study the conservation of forest and wildlife species that are reliant on forest ecosystem within the framework of human population dynamics and its related activities is developed and analysed. The study assessed the impacts of economic measures in the form of incentives on reducing population pressure on forest resources as well as the potential benefits of technological efforts to accelerate the rate of reforestation. Qualitative and quantitative analyses reveals that economic and technological factors have the potential to contribute to resource conservation efforts. However, these efforts can only be used to a limited extent, and contrary to that, the system will be destabilised. Sensitivity analysis identified the parameters pertaining to human population, human activities, economic measures, and technological efforts as the most influential factors in the model.
Open Access
Modeling Radionuclide Transfer from Pasture to Milk in Kisoro, South- Western Uganda
(East African Journal of Science, Technology and Innovation,, 2023-06-30) Habakwiha V,; Oruru B,; Tumps Ireeta W
Determination of radionuclide transfer from animal feeds to animal products and ingestion transfer rates is important in assessing internal radiation risk to humans who consume the animal products. Seventy-nine (79) pasture samples and milk samples were collected from cattle farms in seven sub- counties. Activity concentrations of radionuclides in the samples were determined using gamma spectroscopy. Transfer ratios of radionuclides to from pasture to milk were calculated. Ingestion transfer rates of radionuclide from pasture to cow were also determined. Radionuclide accumulation to the body of the cow was modeled. Contributions to radiological effects due to accumulation of radionuclides in the body were estimated. Transfer ratios of uranium and thorium from pasture to milk varied from 0.07 to 0.17, and 0.05 to 0.17, respectively. The ingestion transfer rates of uranium varied from 3.1 10-6 to 7.6 10-6 y l-1 while for thorium, the ingestion transfer rates varied from 2.2 10-6 to 7.5 10-6 y l-1. The contribution to radium equivalent (Bq l-1), annual effective dose equivalent (mSv y l-1), and excess lifetime cancer Risk due to the radionuclide transfer were 0.074, 0.002, and 0.0061 10-3, respectively. Comparing with the safe values of annual effective dose equivalent in foodstuffs of 0.14 mSv y l-1 which translates to excess cancer risk of 0.42 10-3, these contributions to radiological effects only account for about 1.5% of the total safe value of excess lifetime cancer risk, therefore, radionuclide transfer from pasture to milk causes a minimal radiation hazard to the milk consumers in Kisoro District.
Open Access
Citrus Fruit Farmers’ Adaptation Capacities to Climate Variability in Ngora District, Eastern Uganda.
(Kabale University, 2022) Achuu, Simon Peter; Nachuha, Sarah; Nakizito, Joweria; Musoke, Semakula Henry; Opedes, Hosea Enos
Over the past three decades the government of Uganda prioritized fruits growing in Teso sub-region as a means to promote socioeconomic development. However, climate variability threatens the realization of this initiative and yet inadequate research has been done to address this gap. This study assessed citrus fruit farmers’ adaptation capacities to climate variability in Ngora district, eastern Uganda. Longitudinal and cross-sectional research designs were adopted in which 135 randomly selected farmers were interviewed. Findings indicated that 82% of the respondents attested that rainfall amounts and temperature patterns had changed with the highest rainfall of 1686 mm received in 1991, and the lowest amount of 785mm received in 2009. Average annual temperatures in the same period varied between 23.8ºC and 25.7ºC. These variations contributed to a drop in orange fruit yields from 90% in 2015 to below 54% in 2016. Overall, 94.8% of citrus farmers were aware of the term climate variability and they associated it to variation in rainfall amounts and distribution, rise in surface temperature and occurrence of droughts; 73.3% of the farmers had positive attitude towards climate variability adaptation especially in instances where it directly affected their livelihoods. Only 21% of the farmers did something to adapt to climate variability through irrigating young orange trees. Conclusively, citrus growing provided an option to poverty eradication, however climate variability threatens farmer’s efforts. In a short-run farmers may be encouraged to work in groups. Overall capital investment on irrigation technology by government and or other stakeholders will offer lasting solutions. Keywords: Citrus Fruits - Climatic Factors, Climatic Changes, Agriculture - Environmental Aspects , Ngora District, Uganda.
Open Access
Antiplasmodial Compounds from Millettia Dura.
(Kabale University, 2022) Buyinza, Daniel; Derese, Solomon; Ndakala, Albert
Malaria still poses a big challenge to the health care of many tropical countries. The plasmodium resistance to the conventional drugs is the major hitch in its treatment. Higher plants have produced single line antimalarials and given important lead molecules. On this basis, flavonoids isolated from millettia dura by chromatographic techniques were screened againest W2 and D6 strains of plasmoduim falcipalum. Both, the crude and pure compounds tested showed mild activities against the test organisms. The crude extract of the stem bark had the highest respective activity of 63.7±8.6 and 46.1±4.5 μg/ml against W2 and D6. Of the pure compounds, milletosin was active towards both W2 and D6 with a respective IC50s of 87.9±8.9 and 66.70±30.3 μg/ml. Synergistic effect might have contributed to the relative high activity of the crude than the pure compounds. Basing on the structure activity relationship of the tested compounds, suitable structural modification could be ideal to enhance the antiplasmodial activity. Keywords: Antiplasmodial, Compounds, Millettia Dura.
Open Access
The Suzuki−Miyaura Cross-Coupling−Claisen Rearrangement−Cross-Metathesis Approach to Prenylated Isoflavones
(American Chemical Society, 2022) George, Kwesiga; Julia, Greese; Alexandra, Kelling; Eric, Sperlich; Bernd, Schmidt
Isoflavones were synthesized via Suzuki−Miyaura coupling of 3-iodochromones and para-methoxybenzene- and para- phenolboronic acid. In our hands, conditions commonly used for similar cross couplings turned out to be unsuccessful or difficult to reproduce, for example, due to the unplanned partial cleavage of MOM-protecting groups. Using Pd(dba)2 as a precatalyst and tricyclohexylphosphine as an activating ligand, reliable cross-coupling conditions were identified. In all cases, notably higher yields of isoflavones were obtained with para-phenolboronic acid than with para-methoxybenzene boronic acid. This observation and the commercial availability of para-phenolboronic acid suggest that for the synthesis of the important 3′-prenyl- or 3′,5′-diprenylisoflavone substitution pattern a synthetic route that introduces the prenyl substituents after the Pd-catalyzed cross-coupling step, thereby avoiding laborious and protecting-group-intensive multistep syntheses of C-prenylated arene boronic acids, is advantageous
Open Access
In vitro propagation of Codonopsis pilosula (Franch.) Nannf. using apical shoot segments and phytochemical assessments of the maternal and regenerated plants
(BMC Plant Biology, 2023) Roggers, Gang; Richard, Komakech; Yuseong, Chung; Denis, Okello; Wook, Jin Kim; Byeong, Cheol Moon; Nam, Hui Yim; Youngmin, Kang
Background Codonopsis pilosula (Franch.) Nannf. is a medicinal plant traditionally used in China, Korea, and Japan to treat many diseases including poor gastrointestinal function, low immunity, gastric ulcers, and chronic gastritis. The increasing therapeutic and preventive use of C. pilosula has subsequently led to depletion of the natural populations of this species thus necessitating propagation of this important medicinal plant. Here, we developed an efficient and effective in vitro propagation protocol for C. pilosula using apical shoot segments. We tested various plant tissue culture media for the growth of C. pilosula and evaluated the effects of plant growth regulators on the shoot pro‑ liferation and rooting of regenerated C. pilosula plants. Furthermore, the tissues (roots and shoots) of maternal and in vitro‑regenerated C. pilosula plants were subjected to Fourier‑transform near‑infrared (FT‑NIR) spectrometry, Gas chromatography‑mass spectrometry (GC–MS), and their total flavonoids, phenolics, and antioxidant capacity were determined and compared. Results Full‑strength Murashige and Skoog (MS) medium augmented with vitamins and benzylaminopurine (1.5 mg·L−1 ) regenerated the highest shoot number (12 ± 0.46) per explant. MS medium augmented with indole‑ 3‑acetic acid (1.0 mg·L−1 ) produced the highest root number (9 ± 0.89) and maximum root length (20.88 ± 1.48 mm) from regenerated C. pilosula shoots. The survival rate of in vitro-regenerated C. pilosula plants was 94.00% after acclimatization. The maternal and in vitro‑regenerated C. pilosula plant tissues showed similar FT‑NIR spectra, total phenolics, total flavonoids, phytochemical composition, and antioxidant activity. Randomly amplified polymorphic DNA (RAPD) test confirmed the genetic fidelity of regenerated C. pilosula plants. Conclusions The proposed in vitro propagation protocol may be useful for the rapid mass multiplication and production of high quality C. pilosula as well as for germplasm preservation to ensure sustainable supply amidst the ever‑increasing demand
Open Access
Transcriptome analysis and cytochrome P450 monooxygenase reveal the molecular mechanism of Bisphenol A degradation by Pseudomonas putida strain YC-AE1
(BMC Microbiology, 2022) Adel, Eltoukhy; Yang, Jia; Imane, Lamraoui; M. A., Abo‑Kadoum; Omar, Mohammad Atta; Ruth, Nahurira; Junhuan, Wang; Yanchun, Yan
Background: Bisphenol A (BPA) is a rapid spreading organic pollutant that widely used in many industries espe‑ cially as a plasticizer in polycarbonate plastic and epoxy resins. BPA reported as a prominent endocrine disruptor compound that possesses estrogenic activity and fulminant toxicity. Pseudomonas putida YC‑AE1 was isolated in our previous study and exerted a strong degradation capacity toward BPA at high concentrations; however, the molecular degradation mechanism is still enigmatic. Results: We employed RNA sequencing to analyze the differentially expressed genes (DEGs) in the YC‑AE1 strain upon BPA induction. Out of 1229 differentially expressed genes, 725 genes were positively regulated, and 504 genes were down‑regulated. The pathways of microbial metabolism in diverse environments were significantly enriched among DEGs based on KEGG enrichment analysis. qRT‑PCR confirm the involvement of BPA degradation relevant genes in accordance with RNA Seq data. The degradation pathway of BPA in YC‑AE1 was proposed with specific enzymes and encoded genes. The role of cytochrome P450 (CYP450) in BPA degradation was further verified. Sever decrease in BPA degradation was recorded by YC‑AE1 in the presence of CYP450 inhibitor. Subsequently, CYP‑ 450bisdB deficient YC‑AE1 strain △ bisdB lost its ability toward BPA transformation comparing with the wild type. Furthermore, Transformation of E. coli with pET‑32a‑bisdAB empowers it to degrade 66 mg l−1 of BPA after 24 h. Alto‑ gether, the results showed the role of CYP450 in biodegradation of BPA by YC‑AE1. Conclusion: In this study we propose the molecular basis and the potential role of YC‑AE1cytochrome P450 monooxygenase in BPA catabolism
Open Access
Estimation of Radiological Effects from Consumption of milk from Volcanic areas of Kisoro, South-western Uganda.
(Journal of Radiation and Nuclear Applications An International Journal, 2023-01-01) Vianney, Habakwiha,; Bosco, Oruru; Winston, Tumps Ireeta
Abstract: Determination of activity concentrations of Naturally Occurring Radionuclides in foodstuffs and Radiological Effects from consumption such foodstuffs is very important in assessing internal radiation hazards like cancer to population. The concentration of Naturally Occurring Radionuclides depends on geological formations of specific areas. The aim of this study was to estimate the Radiological effects from consumption of milk from volcanic areas of Kisoro, South-western Uganda. The Radiological Effects that were determined in this study were Radium Equivalent, Annual Effective Dose Equivalent, and Excess Lifetime Cancer Risk. Seventy nine (79) samples of milk were collected from cattle farms in seven sub counties where geological formation was volcanic eruption. Radiological Effects due to Naturally Occurring Radionuclides U-238, Th-232, and K-40 in milk samples were determined. The average activity concentrations were determined using NaI(Tl) detector. The activity concentrations were used to determine the Radiological Effects. The average activity concentrations in milk for U-238, Th-232, and K-40 were; 1.058 Bq l-1, 1.369 Bq l-1, and 19.679 Bq l-1 ,respectively. Average Radium Equivalent was 4.531 Bq l-1, the annual Effective Dose Equivalent was 0.014 mSv y-1 and the Excess Lifetime Cancer Risk was 3 0.041 10 . Samples that were collected from cattle farms that were relatively flat and at lower altitudes had relatively higher activity concentrations hence higher Radiological Effects. The Radium Equivalent, annual Effective Dose Equivalent and, ELCR were all lower than the safe value from consumption of milk by 0.099 Bq l-1 , 0.0019 mSv y-1, and 3 0.005 10 , respectively hence from the results, it is concluded that the milk is safe for human consumption. Since the differences from the safe values are very small, the quantity of milk to be consumed was estimated to be 0.105 litres per day (0.74 litres per week) in order to keep the Radiological Effects low.
Open Access
Temporal and Spatial Seasonal Variations in Quality of Gravity Flow Water in Kyanamira Sub-County, Kabale District, Uganda
(Scientific Research Publishing, 2017) Hannington, Ngabirano; Denis, Byamugisha; Emmanuel, Ntambi
The study was designed to investigate temporal and spatial seasonal variations in quality properties of gravity flow water samples collected from Kigata, Kacuro, Kihanga, Kitibya and Kanjobe located in Kyanamira Sub-County, Kabale District, Uganda. Physical, chemical and biological parameters such as pH, temperature, dissolved oxygen, total dissolved solids, electrical conductivity, turbidity, colour and total suspended solids, total hardness, total alkalinity, chloride, fluoride, nitrates-N, nitrites-N, ammonium-N, sulphates, total phosphate, sodium, calcium, magnesium and some heavy metals were analyzed. Total iron, lead, chromium, copper, zinc, manganese and cadmium were analyzed by atomic absorption spectrometry. Two of the basic biological parameters for drinking water such as faecal coliforms and salmonella were analyzed by incubation followed by counting colony forming units (CFUs). Statistical presentations of data including cluster analysis, dendrograms and principal component analysis were used with the assistance of PAST software. Temperature, pH, TDS dissolved oxygen, cations, anions (chemical parameters) and salmonella, faecal coliforms were the major contributing parameters to gravity flow water’s quality variations during both seasons. Values of pH ranged between 3.78 and 4.84 from March to August in all study sites and they were consistently below the WHO permissible pH range of 6.5 - 8.5. Total suspended solids ranged between 0.66 and 2.17 mg·L−1 and were above the recommended WHO limit of zero value in all study sites. Salmonella and faecal coliforms colonies were present in scaring numbers in the wet season. In March, salmonella counts at Kacuro (14 CFU) and Kanjobe (128 CFU) while faecal coliforms counts at Kacuro (515 CFU) and Kanjobe (228 CFU). The findings of this study call for special attention when using gravity flow water.
Open Access
Effects of Seasonal Variations in Physical Parameters on Quality of Gravity Flow Water in Kyanamira Sub-County, Kabale District, Uganda
(Scientific Research Publishing, 2016) Hannington, Ngabirano; Denis, Byamugisha; Emmanuel, Ntambi
The effect of seasonal variations in physical parameters on quality of gravity flow water was investigated in Kyanamira Sub-County, Kabale District, Uganda. The seasonal variations in the physical parameters (pH, temperature, electrical conductivity (EC), turbidity, colour, total dissolved solids (TDS), and total suspended solids (TSS)) were determined during wet and dry seasons. Composite samples from gravity flow water sources were collected monthly from March to August, 2014 and then analyzed. Temperature was measured using thermometer; pH, EC and TDS were determined using a multimeter, turbidity, colour and total suspended solids were determined by spectrophotometric method. TDS, pH and temperature were the most contributing parameters to water quality variations in both seasons. The mean pH values varied between 3.78 - 4.84 from March to August, 2014 at all study sites. These pH values were consistently below the WHO permissible range of 6.5 - 8.5. Similarly, total suspended solids varied between 0.66 - 2.17 mg∙L−1 and were well above the recommended WHO limit of zero mg∙L−1 at all study sites. Turbidity mean values varied between 0.83 - 3.7 NTU and were outside the recommended limits of 3 NTU at Kigata (3.7 NTU) only. Temperatures (20.3˚C - 21.15˚C) for all the study sites were within the recommended limit of 20˚C - 30˚C in water for domestic purposes. The mean values of physical parameters for the wet season were: temperature (21.12˚C), colour (12.5 PtCoU), turbidity (3.4 NTU), TDS (76.76 mg∙L−1), TSS (2.13 mg∙L−1), pH (4.19) and EC (152.7 μS∙cm−1) were different from those of the dry season (temperature (20.99˚C), colour (0.93 PtCoU), turbidity (0.53 NTU), TDS (77.33 mg∙L−1), TSS (0.67 mg∙L−1), pH (4.86) and EC (158.65 μS∙cm−1). Basing on these findings above, it was evident to justify discouraging the use of gravity flow water at these study sites for domestic purposes without proper treatment.