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  • ItemOpen 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
  • ItemOpen 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.
  • ItemOpen 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.
  • ItemOpen 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.
  • ItemOpen 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.
  • ItemOpen 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.
  • ItemOpen 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
  • ItemOpen 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
  • ItemOpen 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
  • ItemOpen 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.
  • ItemOpen 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.
  • ItemOpen 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.
  • ItemOpen Access
    Citrus fruit farmers’ adaptation capacities to climate variability in Ngora district, Eastern Uganda
    (Kabale University Interdisciplinary Research Journal (KURJ), 2022) Simon Peter, Achuu; Sarah, Nachuha; Joweria, Nakizito; Henry Musoke, Semakula; Hosea Enos, Opedes
    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 solution
  • ItemOpen Access
    Pesticide application and water quality in Doho and Kibimba rice irrigation schemes, eastern Uganda
    (Kabale University Interdisciplinary Research Journal (KURJ), 2022) Sulaiman, Abubakar Aminua; Sarah, Nachuha; Zakia, Tebetyoc
    The number and amount of agrochemicals used has increased dramatically world over and their toxic nature has raised concern about environmental impact and effects on human health. Considering that agriculture is a major source of income in most developing countries, crop damage from pest infestation is of great concern to many farmers. These farmers are therefore motivated to apply pesticides. However, runoff from such farmlands unintendedly contaminates the water sources thereby causing harm to aquatic life and contaminates drinking water. This study was carried out at Doho and Kibimba irrigation schemes, which are the two commercial paddy rice growing areas in Uganda. The aim of this study was to investigate the effect of pesticide application on water quality in these two schemes and assess community awareness of the dangers of pesticide application. A cross sectional research design was used to collect data. A total of 60 samples (30 from each site) on physicochemical characteristics were collected in situ using standard equipment. 200 local community members (100 from each scheme) were randomly selected while on the farm and interviewed. Statistical analyses were conducted using Statistical Package for Social Sciences (SPSS) program, version 20. Results showed that there were significant spatial differences in all the physical chemical properties of water in Doho Rice Scheme (P<0.05), while significant spatial variations were recorded for only pH, temperature at Kibimba rice scheme (P<0.05). Independent t-test results showed that water pH, temperature and turbidity varied significantly between Doho and Kibimba (P<0.05). Herbicides such as rocket, Diazine, Cypermatrine glyphosate were being used by famers with rocket frequently used at Doho while glyphosate was the only one used at Kibimba. Majority of the farm workers at Kibimba (96.9%) reported to have always used protective devices when handling pesticides and the reverse was true for farm workers at Doho despite the training on pesticide usage. The study therefore recommends regular water quality monitoring and sensitization of farmworkers on the dangers of improper pesticide use.
  • ItemOpen Access
    Application of Discrete-time semi-Markov Model to the Stochastic forecasting of Capital assests as stock.
    (Far East Journal of theoretical Statistics, 2021) Nafiu, Lukman Abiodun; Patrick, Weke; Alieu Jallow, Mamadou; Carolyne, Ogutu
    In this paper, we developed and applied a stochastic model based on Discrete-time Semi Markov chain approach and its generalizations to study the high frequency price dynamics of traded stocks. Semi Markov is a stochastic process that generalizes both the Markov chain and the Markov renewal processes. it is well known that the performances of the stock market or factors that move stock prices are technical factors, fundamental factors and market sentiments.
  • ItemOpen Access
    Optimal control analysis of Taenia saginata bovine cysticercosis and human taeniasis
    (Elsevier, 2022) Damian, Kajunguri; Joshua, A. Mwasunda; Jacob I, Irunde
    Bovine cysticercosis and human taeniasis are neglected food-borne diseases that pose challenge to food safety, human health and livelihood of rural livestock farmers. In this paper, we have formulated and analyzed a deterministic model for transmission dynamics and control of taeniasis and cysticercosis in humans and cattle respectively. The analysis shows that both the disease free equilibrium (DFE) and endemic equilibrium (EE) exist. To study the dynamics of the diseases, we derived the basic reproduction number R0 by next generation matrix method which shows whether the diseases die or persist in humans and cattle. The diseases clear if R0 < 1 and persist when R0 > 1. The normalized forward sensitivity index is used to derive sensitive indices of model parameters. Sensitivity analysis results indicate that human’s and cattle’s recruitment rates, infection rate of cattle from contaminated environment, probability of humans to acquire taeniasis due to consumption of infected meat, defecation rate of humans with taeniasis and the consumption rate of raw or undercooked infected meat are the most positive sensitive parameters whereas the natural death rates for humans, cattle, Taenia saginata eggs and the proportion of unconsumed infected meat are the most negative sensitive parameters in diseases’ transmission. These results suggest that control measures such as improving meat cooking, meat inspection and treatment of infected humans will be effective for controlling taeniasis and cysticercosis in humans and cattle respectively. The optimal control theory is applied by considering three time dependent controls which are improved meat cooking, vaccination of cattle, and treatment of humans with taeniasis when they are implemented in combination. The Pontryagin’s maximum principle is adopted to find the necessary conditions for existence of the optimal controls. The Runge Kutta order four forward-backward sweep method is implemented in Matlab to solve the optimal control problem. The results indicate that a strategy which focuses on improving meat cooking and treatment of humans with taeniasis is the optimal strategy for diseases’ control.
  • ItemOpen Access
    Manufacturing Export Performance: A Trend Analysis Approach
    (INTERNATIONAL JOURNAL OF APPLIED MATHEMATICS AND INFORMATICS, 2021) Nafiu, Lukman Abiodun; George Stanley, Kinyata
    The study examined the export performance using a trend analysis approach. A graphical demonstration showing the trend of export performance in Nigeria over time was displayed. It also identifies the major determinants of manufacture exports in Nigeria using ordinary least square approach which shows that an increase in the average tariff rate would lead to a decline in the manufacturing exports and its statistically significant at the 5% level of significance. Capacity utilization has a negative and insignificant with manufactured exports. Also, there is a positive and significant relationship between exchange rate and trade openness at 1 and 5% level of significance respectively.
  • ItemOpen Access
    Optimal control and Cost-Effectiveness Analysis of Taeniasis and Cysticercois in Humans, Pigs and Cattle.
    (Commun. Math. Biol. Neurosci, 2021) Joshua, A. Mwasunda; Jacob I, Irunde; Damian, Kajunguri; Dmitry, Kuznetsov
    Taeniasis and cysticercosis are neglected food-borne diseases that pose challenge to food safety, human health and livelihood of rural livestock farmers. In this paper, an optimal control problem for the dynamics and control of taeniasis and cysticercosis in humans, pigs and cattle with its cost-effectiveness analysis is presented and analysed to determine the optimal and cost-effective strategy for disease control. A combination of two or more time dependent controls involving vaccination of pigs and cattle, meat inspection, environmental hygiene and sanitation, and the treatment of humans who are infected with taeniasis is carried out to study their impacts on disease control. The Pontryagin’s maximum principle is adopted to find the necessary conditions for existence of the optimal controls. The Runge Kutta order four forward-backward sweep method is implemented to solve the optimal control problem. The incremental cost-effectiveness ratio (ICER) is applied to determine the most cost-effective strategy for disease control. The optimal control results indicate that the strategy which focus on the combination of all interventions or that exclude vaccination of pigs and cattle is the most effective optimal control strategy in disease control. However, cost-effectiveness analysis results show that a strategy which excludes vaccination of pigs and cattle is the most cost-effective strategy for disease control. Based on these results, we recommend that interventions which focus on meat inspection, treatment of humans who are infected with taeniasis and improvement in hygiene and sanitation should be considered to control the transmission of taeniasis and cysticercosis in humans, pigs and cattle at a minimal cost.
  • ItemOpen Access
    Pesticide residues in vegetables produced in rural south-western Uganda
    (Elsevier, 2021) Hannington, Ngabirano; Grace, Birungi
    This study investigated seven pesticides in vegetables produced in rural South-western Uganda to determine their suitability for human consumption. Pesticide residue concentrations (ppm) were determined using QuEChERS method, LC–MS/MS, GC–MS/MS and UV–Vis. Cypermethrin, dimethoate, metalaxyl, profenofos, malathion, dichlorvos and mancozeb concentrations detected in sprayed samples ranged between 0.00403 and 0.05350, 0.17478–62.60874, 0.12890–3.55681, 0.00107–0.59722, 0.03144–0.63328, 0.00240–0.34102 and 0.00001–0.00244, respectively. The residues exceeded MRLs in sprayed samples (59.52%), unsprayed samples (18%) and market samples (8%). The quality index of the market vegetables was found to be optimal (14.29%), good (75%), adequate (3.57%) and inadequate (14.29%). Pesticide residues may lower food quality and pose risk to human health. Therefore, regulation and monitoring pesticide residues in vegetables produced in southwestern Uganda in order to avoid harmful effects on human health would be paramount.
  • ItemOpen Access
    Modeling and analysis of taeniasis and cysticercosis transmission dynamics in humans, pigs and cattle
    (Springer, 2021) Joshua, A. Mwasunda; Jacob I, Irunde; Damian, Kajunguri; Dmitry, Kuznetsov
    Taeniasis and cysticercosis pose a significant challenge to food safety and public health. Cysticercosis reduces the market value for pigs and cattle by making pork and beef unsafe for consumption. In this paper, a mathematical model for the transmission dynamics of taeniasis and cysticercosis in humans, pigs and cattle is formulated and analyzed. The analysis shows that both the disease free equilibrium (DFE) and the endemic equilibrium (EE) exist. To study the dynamics of the diseases, we derived the basic reproduction number R0 by next generation matrix method. When R0 < 1, the DFE is globally asymptotically stable whereas when R0 > 1 the EE is globally asymptotically stable. The normalized forward sensitivity index was used to determine sensitive parameters to the diseases. Humans’ recruitment rate, probability of humans’ infection with taeniasis and the defecation rate of taenia eggs by humans with taeniasis are the most positive sensitive parameters to diseases’ transmission whereas the human natural death rate is the most negative sensitive parameter. However, it is biologically unethical and not practical to increase human natural mortality rate for disease control. In this case, other parameters with negative sensitivity indices such as death rate of taenia eggs and proportions of unconsumed infected beef and pork can be considered for disease control. Generally, to control the diseases, more efforts should be made directed to reducing the number of humans who have taeniasis and defecate in the open environment. Also meat inspection and indoor keeping of cattle and pigs should be emphasized.