College of Natural and Computational Sciences

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The College of Natural and Computational Sciences advances education, research, and innovation in natural sciences, mathematics, statistics, and computational disciplines.

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1,4-BENZOQUINONE MODIFIED CARBON PASTE ELECTRODE FOR VOLTAMMETRIC INVESTIGATIONOF DOPAMINE
(HAWASSA UNIVERSITY, 2025-04) KASSA BEKO
Dopamine (DA) is one of electrochemically active molecule; electrochemical techniques currently have received great interest for their investigation due to their simplicity, cost effective, low detection limit, and fast response time. This study investigates the electrochemical oxidation of dopamine using a low-cost and sensitive voltammetric method based on a 1,4-Benzoquinone modified carbon paste electrode. Cyclic voltammetry revealed significant enhancements in the oxidative peak current for dopamine at the modified electrode compared to unmodified carbon paste electrode, indicating its electrocatalytic properties. Scan rate, pH, differential pulse amplitude, and concentration of dopamine were optimized for the investigation of dopamine. The optimized values were 100 mV/s, 7, and 240mV, respectively. The voltammogram resulted from those parameters showed that quasireversible nature of the analyte towards modified electrode with the transfer of two electrons per molecule of the analyte. The dependence of anodic peak current on the square root of scan rate with high correlation coefficients (R2 =0.99907 and scan rate (R2 =0.99103) indicated that, the diffusion control is dominant, but adsorption also plays a role. Key kinetic parameters were calculated: anodic transfer coefficient (α =0.798), diffusion coefficient (D=2.18×10−7 cm 2 /s), and heterogeneous electron transfer rate constant (Ks,h=2.26×10−4 cm/s). Anodic transfer coefficient (α =0.798) value is closer to one this suggests that anodic process is more favorable. Optimization of experimental conditions led to be a linear response for DA concentration ranging from 1.0 × 10−3 M to 3.5 × 10−3 M, with a detection limit of 1.39 × 10−4 M using cyclic voltammetry and 7.64 × 10−5 M with differential pulse voltammetry. The result suggests that 1,4-BQMCPE is a promising electrode material for the development of electrochemical sensors for DA detection.
A COMPARATIVE ANALYSIS OF PHYSICOCHEMICAL PARAMETERS AND MINERAL CONTENT IN COW AND CAMEL MILK FROM AGA WAYU DISTRICT, GUJI ZONE, OROMIA, ETHIOPIA
(HAWASSA UNIVERSITY, 2025-06) DINAOL BAYU
This study aims to analyze and compare the physicochemical properties and mineral composition of cow’s and camel’s milk. Milk samples were collected from the Aga Wayu district in the Guji zone of the Oromia region, Ethiopia, using a proportional random sampling method. The physicochemical parameters analyzed included pH, titratable acidity, ash content, specific gravity, protein content, fat content, moisture content, total solids, and boiling point. Additionally, the concentrations of selected minerals (phosphorus, sodium, calcium, and potassium) were measured. The results showed that cow’s and camel’s milk exhibited similar physicochemical properties, with comparable pH (5.8 ± 0.5), titrateble acidity (0.20 ± 0.01), ash content (0.84 ± 0.12%), specific gravity (1.04 ± 0.11), protein content (3.32 ± 0.43%)for cow, fat content (3.6 ± 0.48%) and boiling point (92.66°C)for camel. The concentrations of sodium (3.63 ± 1.23 mg/L) and phosphorus (2.43 ± 0.39 mg/L) were also similar in both types of milk. However, cow’s milk had higher moisture content (85.13 ± 2.65%) and calcium levels (22.44 ± 2.41 mg/L) compared to camel’s milk, which had lower moisture (82.83 ± 1.22%) and calcium (17.07 ± 1.38 mg/L). Conversely, camel’s milk contained higher total solids (18.26 ± 0.50%) than cow’s milk (14.82 ± 2.11%). In conclusion, camel’s milk was found to have higher protein and lactose content than cows’s milk, while cow’s milk had a greater fat content. These findings highlight the distinct nutritional profiles of the two types of milk, which may have implications for their dietary applications.
A Laboratory Course in Nanoscience and Nanotechnology
(Taylor & Francis, 2015) Gérrard Eddy Jai Poinern
A Study of Incomplete Fusion Reaction and its Correlation with Projectile Energy and Entrance channel Mass-Asymmetry in some 12C/16O-Induced Reactions at ≈3–9 MeV/nucleon
(HAWASSA UNIVERSITY, 2024-05) Mustefa Kedir Dubiso
In this work, the effects of projectile energy and entrance channel mass-asymmetry on incomplete fusion reaction in 12C + 128Te, 12C + 141Pr, 12C + 159Tb, 16O + 130Te, 16O + 159Tb and 16O + 181Ta, projectiles + targets systems at ≈ 3-9 MeV/nucleon were studied. Cross sections of various reaction products populated via complete and incomplete fusion of 12C projectile with 128Te, 141Pr and 159Tb-targets and 16O projectile with 130Te, 159Tb and 181Ta targets were calculated using the reaction model code PACE4. The predicted cross sections were compared with experimentally measured data from EXFOR database. For a representative non α-emitting ( 12C, 4n) channel from a representative in 12C + 159Tb system, experimentally measured cross sections agreed with PACE4 prediction for level density parameters K=10. For the same level density parameters a representative α-emitting (12C, α3n) from a representative in 12C + 128Te projectile + target system, the experimentally measured cross sections are higher than the PACE4 predicted. The observed difference is attributed to the contribution of incomplete fusion following the prompt break-up of the projectiles into α-clusters. An attempt was made to deduce the contribution of incomplete fusion reactions from presently investigated projectile and target systems. It was found that the incomplete fusion fraction, in general, increases with the increase in projectile energy. Furthermore, the result indicated that at the same normalized relative velocity, the incomplete fusion fraction is higher for mass-asymmetric projectiles and targets systems
A Thesis Submitted to School of Graduate Studies College of Natural and Computational Science in Partial Fulfillment of the Requirements for the Degree of Master of Science in Physics.
(2024-05) Negash Gimbo
In this work, theoretical predicted production cross section were made using COMPLETE, EMPIRE-3.2 and TALYS-1.95(G) reaction model codes for the production of medically important 88Y, 89Zr, 90Y and 99Mo radionuclides in the interaction of α-projectile with 89Y and 96Zr-targets at ≈10-60 MeV. The theoretical predicted production cross sections were compared with the experimental data available in the EXFORE database. The TALYS-1.95(G) code predicted production cross sections of medically important 88Y, 90Y, and 89Zr radionuclide, in general, are found to be in good agreement with experimental measured production cross sections over the entire energy range except for 99Mo radionuclide. Pearson‟s statistical coefficients confirmed a strong positive correlation between TALYS-1.95(G) codes predicted and experimentally measured production cross section except for 99Mo. Furthermore, it was found that the TALYS-1.95(G) predicted and experimentally measured production cross-sections in general attained maximum values below ≈45MeV α-energy for medically important 88Y, 90Y, and 89Zr radionuclides via complex (α,x) channel. Thus the obtained result can be used as reference cross-section data for optimized production of medically important 88Y, 90Y, 89Zr and 99Mo radionuclides using single α + 89Y, 96Zr system.
A Thesis Submitted to School of Graduate Studies College of Natural and Computational Science in Partial Fulfillment of the Requirements for the Degree of Master of Science in Physics.
(HAWASSA UNIVERSITY, 2024-05) Tekalegn Mitiku
This work studied the production cross section and yield of medically important radionuclides, such as 68Ga and 64Cu, generated during irradiation of 66Zn-target with α-projectile at ≈ 10-40 v MeV. The experimental cross-sections taken from the EXFOR database were compared with the theoretical model calculations using nuclear reaction model codes COMPLETE, TALYS1.95 (G), and EMPIRE3.2. A good agreement was achieved for the measured data and calculated production cross-section using the TALYS1.95 (G) code. The 68Ga and 64Cu yields were computed using TALYS1.95 (G) predicted cross-section data. Also, the possible isotopic impurities were identified, and their contributions were estimated. Based on the yield calculations, the production yield of 68Ga was found to be 39.6 GBq/μAh, at 28 MeV without any significant contribution from its isotopic impurities 67Ga and 66Ga; in addition a yield value of 85.9 MBq/μAh at 40 MeV was obtained for medically important 64Cu radionuclide with negligible isotopic impurities contributions from 66Cu and 62Cu radionuclides
ADSORPTIVE REMOVAL OF LEAD ION FROM AQUEOUS SOLUTION USING CRYSTALINE NANOCELLULOSE PREPARED FROM MAIZE COBS
(2024-03) GETAHUN ESHETU
Heavy metals significantly impact the environment due to their non-biodegradable, toxic, and carcinogenic behaviors. Lead contaminants impose severe health impacts on humans and the water environment. Therefore, eco-friendly and efficient lead ion removal practices such as nanotechnology are an urgent requirement for the abatement of lead pollution. The aim of this study was to evaluate the removal of lead from an aqueous solution using maize cob cellulose Nano crystals. In the present study, crystal Nano cellulose was synthesized from maize cob. The crystal Nano cellulose synthesized was characterized by using FTIR, XRD and SEM. FTIR analysis reveals presence of functional groups with a high chelating capacity, as identified via FTIR. From SEM analysis the crystal Nano cellulose was noticed to be disordered and irregular in shape. The adsorption capacity of the crystal Nano cellos was 3.85 mg/g. The adsorption process was evaluated by adjusting the pH, dose, initial concentration and temperature. Optimum conditions were dose of 0.16 gram initial concentration of 10 ppm, contact time of 115 minute, pH of 6 and temperature of 450 c. Based on the optimal parameters, the kinetics were evaluated using the pseudo first and pseudo second order models based on that pseudo second order more fit than pseudo first order model. Equilibrium data were represented better by the Freundlich model than the Langmuir model which describes multilayer adsorptions. The adsorbent-formulated from crystalline Nano cellulose presented a good capacity to remove lead from aqueous media.
AIR POLLUTANTS IN SCHOOL, URBAN, AND INDUSTRIAL ENVIRONMENTS OF HAWASSA CITY, ETHIOPIA: LEVELS AND POSSIBLE HUMAN HEALTH RISK ASSESSMENT
(HAWASSA UNIVERSITY, 2024-06) ABEBECH NUGUSE AMARE
Air pollution has received enormous attention globally due to its detrimental effects on human health, especially on susceptible populations such as children. However, there is scarce data on concentrations and sources of volatile organic compounds (VOCs), inorganic gaseous pollutants (NO2, CO, and SO2), and particulate matter (PM2.5 and PM10) in Ethiopia, particularly Hawassa City. The objective of this PhD work was to determine the indoor and outdoor concentrations of VOCs, PM2.5, PM10, NO2, CO, and SO2 in schools, urban, and industrial environments in Hawassa City, Ethiopia, and evaluate potential health concerns. VOC samples were taken via the passive sampling method using Tenax TA as a sorbent and analyzed using thermal desorption-gas chromatography-mass spectrometry (TD-GCMS). The concentrations of PM10 and PM2.5 were measured using a portable gas monitor device (HoldPeak Laser PM meter, HP 5800D). Levels of NO2, CO, and SO2 were measured using the Aeroqual Series 500 Portable Air Quality Monitor (Aeroqual Ltd., New Zealand). Concentrations of 76 VOCs were determined in air samples from the classrooms and playgrounds of eight primary schools in Hawassa. Concentrations of PM2.5, PM10, NO2, CO, and SO2 were also measured in the outdoor and indoor environments of ten primary schools in Hawassa, Ethiopia. Additionally, indoor and outdoor concentrations of PM2.5, PM10, NO2, CO, and SO2 were measured in urban and industrial areas of Hawassa City, Ethiopia, in the dry and wet seasons. xxiii The highest total VOCs (TVOCs) concentration (83 μg/m3 ) was observed in a classroom of School 2, followed by a classroom of School 1 (76 μg/m3 ), while the smallest TVOC concentration, 37 μg/m3 , was recorded in the playground of School 8. Among the BTEX, toluene was the most dominant in all samples, ranging from 33% in School 4 to 38% in School 1 of ∑BTEX. The I/O ratios of individual VOC in the schools ranged from 0.44 in School 4 to 9.21 in School 2. The highest cumulative cancer risk (CCR×106 ) and the total hazard ratio indicator (THRI) values were 126 and 1.58E-01, respectively, in a classroom of School 4. The concentrations of PM2.5, PM10, and NO2 in the ten primary schools ranged 11–66.3, 30.8–399.7, and 60.5–152 µg/m3 , respectively, and CO and SO2 were not detected in any of the schools. The hazard quotient (HQ) for PM2.5 and PM10 was greater than one in 20% and 50% of the indoor sampling locations, respectively, suggesting moderate risks. The Air Quality Index (AQI) at 40% and 30% of the outdoor sampling sites were unhealthy for sensitive groups due to exposure to PM2.5 and PM10, respectively. The concentrations of PM2.5 and PM10 were found to be above the WHO mean guidelines in 55% and 85% of the sampling sites, respectively, indicating poor quality of the air. In the urban and industrial areas, PM2.5, PM10, and NO2 were detected during both seasons and at all sampling sites. CO was detected during the wet season but not detected at all during the dry season at any of the sites. SO2 was detected only at one site, S17 (ambient of industry 1), during both studied seasons. During the dry season, the average concentrations of PM2.5, PM10, and NO2 ranged from 8.8–310.7, 20.1–515.8, and 40.0– 123.7 µg/m3 , respectively. In the wet season, the ranges for PM2.5, PM10, NO2, and CO levels were 17.2–117.4, 24.3–167.2, 31.8–111.3, and 77–33312 µg/m3 , respectively. xxiv In both the wet and dry seasons, the hazard quotient for PM2.5 and PM10 was greater than one, suggesting a non-carcinogenic effect. The PM2.5 excess lifetime cancer risk ranged from 0.1 to 0.7, which was greater than the recommended range by the WHO and the US EPA, implying a considerable health risk in urban and industrial areas. The CCR and THRI values indicated that the exposure of children to the measured concentrations of benzene may have potentially harmful effects. Additionally, the AQI, HQ values, and concentrations of PM2.5 and PM10 indicated poor air quality in the schools and suggested a significant health risk for all populations around the schools.
AMathematical Model Analysis on the Dynamics of Online GameAddiction with Optimal Control
(HAWASSA UNIVERSITY, 2024-06) Iyasu Kaleb
Excessive playing of online games leads to addiction, which causes academic under achievement and prevents the daily achievement of goals. Symptoms of addiction are spend ing more time gaming online and irritability, while risk factors are low self-worth, anxiety and depression. This thesis study focuses on the mathematical model analysis of the dynam ics of online game addiction with optimal control. We demonstrated the existence, positivity and boundedness of the solution of the dynamical system. The system has two equilibrium points, namely the online game addiction free and endemic equilibrium points, and their stability was determined using the linearization technique, the Castillo-Chavrz theorem and LaSalles’s invariant principle. The basic reproduction number (R0) of the model was cal culated using the principle of the next generation matrix and the sensitivity indices of R0 to the model parameters were investigated. Additionally, bifurcation analysis was performed to verify the backward and forward bifurcations, and from the analysis, we observed that the model system exhibits forward bifurcation at R0 = 1. The optimal control problem of the model was analyzed using Pontryagin’s Maximum Principle and the characterization of the optimal control was constructed. Numerical simulations were performed to verify the accuracy of the analytical results using MATLAB software. From the numerical simula tion of sensitivity analysis, decreasing the contact rate with addicted(β1) and incompletely recovered(β2) individuals, the addiction rate(δ), the re-addiction rate(ω) and the incomplete recovery rate of treated individuals(τ) decreases the reproduction number. Using optimal control, the combined strategy of minimizing the contact rate with addicted individuals and the re-addiction rate of incompletely recovered individuals minimizes the exposed and ad dicted individuals as well as the associated cost
ANALYSIS OF HEAVY METAL CONCENTRATIONS IN COATINGS OF SCRATCH LOTTERY CARDS AND SCRATCH PHONE RECHARGE CARDS IN ETHIOPIA USING FLAME ATOMIC ABSORPTIONS SPECTROSCOPY
(HAWASSA UNIVERSITY, 2024-06) KEDIR EDAO WABE
This research work was focused on the presence and level of heavy metals in coatings of scratch mobile cards and lottery cards in Ethiopia using flame atomic absorptions spectroscopy .The study mainly stressed on heavy metals such as Copper, Lead, Manganese, Chromium, and Nickel, so that the coatings of this scratch mobile cards and lottery cards were acidic digested for the determinations of the presence and levels of heavy metals concentrations. According to the laboratory results the concentrations of heavy metals in certain amounts in all these heavy metals indicated above and when we saw the levels and concentration of this heavy metals one by one with a value Cu(0.954,1.07) ,Pb(0.085,0.071), Mn(0.084,0.055), Cr(0.073,0.060) and Ni(0.051,0.041) in ppm respectively for both mobile recharge and lottery cards. This indicated that heavy metals Cu had the largest value as we compared with heavy metals and heavy metals Ni had the least and the rest heavy metals were next to the copper metal respectively for both mobile recharge cards and lottery cards and the calibrations of concentration to absorbance would obtained the result and the concentration of heavy metals in coatings of scratch mobile recharge cared and lottery cards in standards solution and its within R2 (0.994-0.999). Although the concentrations of all this heavy metal in the scratch cards are low, over time they can accumulate on the environment if not properly disposed, and can cause health problems as they are poisonous and dangers to human health when taken above the limit set by WHO. Therefore public awareness become advised not to use finger nails to scratch mobile recharged card and lottery cared rather it is advisable to use sharp edge materials in order to scratch this mobile recharge cards and lottery cards
Analysis of Mathematical Model on the Transmission Dynamics of COVID-19 with Protected and Hospitalized individuals.
(HAWASSA UNIVERSITY, 2024-11) Teshale Deboch
Mathematical modelling is important for better understanding of disease dynamics and developing strategies to manage rapidly spreading infectious diseases. In this thesis, we propose a mathematical model to investigate coronavirus diseases (COVID-19) transmission in the presence of protected and hospitalized classes. Analytical and numerical approach is employed to investigate the results. In the analytical study of the model, we have shown the local and global stability of disease-free equilibrium, existence of the endemic equilibrium and its local stability, positivity of the solution, invariant region of the solution and sensitivity analysis of the model is conducted. From these analyses, we found that the disease-free equilibrium is globally asymptotically stable for 𝑅0 < 1 and is unstable for 𝑅0 > 1. A locally stable endemic equilibrium exists for 𝑅0 > 1, which shows the persistence of the disease if the reproduction number is greater than unity. Using sensitivity analysis we establish that 𝑅𝑜 is most sensitive to the rate of Protection of Susceptible individuals 𝜃 and that a high level of protection needs to be maintained as well as hospitalization to control the disease. Finally, we performed numerical simulations using MATLAB software Ode 45 codes to supplement the effectiveness of the analytical findings.
Analysis of Unhealthy Attitude on Marriage and its Impact on the Dynamics of Divorce using Mathematical Model
(HAWASSA UNIVERSITY, 2024-06) Etsehiwot Gobezayewu
Divorce is the dissolution of two partners marriage, which is a serious problem challenging the establishment of the family in a routine manner and causing severe impacts on the emotional and mental health of the individual. In this thesis, we modified and analyzed a mathematical model that describes the spread of unhealthy attitude on marriage and its impact on the dynamics of divorce. The population was divided in to six compartments and analyzed using a system of non-linear ordinary differential equations. The basic reproduction number R0 is calculated using next generation matrix operator. We have found two equilibrium points, namely the unhealthy attitude free equilibrium point and the unhealthy attitude present equilibrium point. We have established the conditions for the stability of equilibrium points. The unhealthy attitude free equilibrium point is both locally and globally stable if R0 < 1, and the unhealthy attitude present equilibrium point is also both locally and globally stable if R0 > 1. The modified model exhibits a forward bifurcation whenever R0 < 1, which indicates the threshold parameter plays an important role in reducing the spread of unhealthy attitude on marriage. Secondary data sources for divorce case were collected from Hawassa first instance court. The data were fitted to the model to estimate some parameter values using Least Square optimization method. Sensitivity analysis was performed to identify parameters which are sensitive to the reproduction number. According to this the contact rate between married and individuals who have unhealthy attitude β1 and the rate of transfer from unhealthy attitude to healthy counseling φ plays an important role in reducing R0 less than unity. Finally, we performed numerical simulations using ODE 45 codes to support the analytical results in agreement with numerical solutions.
ANALYZING THE EFFECTIVENESS OF THE JIGSAW LEARNING MODEL IN IMPROVING SECONDARY SCHOOL BIOLOGY EDUCATION IN GEDEO ZONE, SOUTH ETHIOPIA
(Hawssa University, 2025-05) YIDNEKACHEW AWRARIS
This study evaluated effects of Jigsaw learning model in improving secondary school biology education in Gedeo Zone, South Ethiopia. A quasi-experimental pretest-posttest design was employed, involving two secondary schools. One school (n = 40 students) was randomly assigned to the intervention group, while the other (n = 41 students) served as the control group. Data were collected using multiple choice biology achievement tests, close ended likert-acle student engagement questionnaires, semi-structured interviews, document analysis, and classroom observations. The quantitative data were analyzed using descriptive statistics, t-tests, MANOVA, correlation, and regression analysis, while the qualitative data were analyzed thematically through coding and categorization of interview transcripts, documents, and observational notes. Analysis of the pretest data revealed that no significant difference in biology achievement score (t(79) =1.34, P = 0.187), peer relationship scores (t(79) = 1.544, P = 0.126), academic support scores (t(79) =0.391, P = 0.697), and Overall learning gains scores (t(79) = 0.556, P = 0.58). After a 16-week intervention, the Jigsaw model resulted in a statistically significant improvement in the experimental group's post-test biology achievement scores (t(79) = 6.19, P < 0.05), Peer relationships scores (t(79) = 14.334, P< 0.05), academic supports scores (t(79) = 8.395, P < 0.05), and overall learning gains scores (t(79) = 9.463, P < 0.05). However, the intervention showed no notable impact on gender-based post-test achievement scores among experimental group participants (mean difference = 2.2, ES = 0.008, P > 0.05). The MANOVA results showed that the jigsaw model had broader impacts on peer relationships, academic support, and overall learning gains revealing moderate to substantial effects (Partial η2 = 0.471 0.722). Correlation analysis revealed strong positive associations among peer relationships, academic support and overall learning gains. Multiple regression analysis indicated that peer relationships and academic support together explained 43.2% of the variance in learning gains in biology. The qualitative findings supported these results; the Jigsaw model has positive impact on student engagement and understandings, achievement of course objectives and builds relationships with their peers. However, several challenges were identified, including unfamiliarity with the method, resource constraints, and resistance from some teachers. These findings suggest that the Jigsaw model has the potential to shift biology instruction from content driven to learner-centered approach. To maximize impact, schools should invest in teacher training, allocate resources for cooperative learning, and integrate Jigsaw into curricula. Future research should explore long-term sustainability and scalability across diverse Ethiopian educational settings.
APPLICATION OF MULTISTATE MARKOV MODEL IN ANALYZING THE TRANSI TION OF HYPERTENSION AT HAWASSA UNIVERSITY COMPREHENSIVE SPECI ALIZED HOSPITAL, ETHIOPIA
(HAWASSA UNIVERSITY, 2023-11) TAYESEW SHEGAW MOLTOT
Background: Hypertension is the primary cause of cardiovascular death as well as other serious conditions like heart attacks, strokes, chronic heart failure, and kidney failure. In Ethiopia, cardiovascular disease is by far the most common NCD-related cause of death, and hypertension is one of the main risk factors. this study aimed to model hypertension progression and identify factors determining the transition rate between different stages of hypertension among hypertensive patients under follow up at HU-CSH recorded between September 2017 to August 2022 using multistate Markov model by the European Society of Cardiology and the European S ociety of Hypertension's guidelines for blood pressure. Method: Data for this study was obtained from Hawassa university comprehensive specialized Hospital, with a total of 210 hypertensive patients who were under follow up from September 2017 to August 2022 were included in the study. A twenty-four-month transition probability between prehypertension progression stages or state 1 (systolic <140 mm Hg & diast olic <90 mm Hg), grade 1 hypertension or state 2 (systolic 140-159 mm Hg & diastolic 90-99 mm Hg), grade 2 hypertension or state 3 (systolic 160-179 mm Hg diastolic 100-109 mm Hg) and grade 3 or state 4 hypertension (systolic ≥180 mm Hg & diastolic ≥110 mm Hg) and factors determining the rate of progression among patients was estimated. Result and Discussion: Among the total number of patients included in the study, 56.7% were female and 43.3% were male. Among the total number of patients included in the study, 56.7% were female and 43.3% were male. Among them, 22.9% of patients were in state 1 at initial checkup, 36.2 in state 2, 23.8% in state 3 and 17.1% in state 4 hypertension. The estimated 24 m onths transition probability for the hypertensive patients was 15.1 % (95% CI: 0.108, 0.210) from state 1 to state 2, 1.4% (95% CI: 0.009, 0.023) from state 1 hypertension to state 3, 0.2 %(95% CI:0.001, 0.003) from state 1 to state 4, 12.8% (95% CI:0.091, 0.177) from state 2 hypertension to state 3, 2.6% (95% CI:0.017, 0.041) from state 2 hypertension to state 4, 20.5% (95%CI:0.137, 0.290) from state 3 to state 4 and 83.3% (95%CI: 0.768, 0.881), 72.6% (95%CI: 0.660, 0.778), 45.1% (95%CI: 0.368, 0.529) and 67.8% (95%CI: 0.577, 0.777) were the estimate probability of remaining at state 1, state 2, state 3 and state 4 respectively. The mean time a pati ent takes to transition from state to state was estimated and state 1 hypertension had the longest estimated time followed by state 2, while state 3 had the shortest estimated sojourn time. By comparing a likelihood ratio test statistic, the full model fits significantly better than the null model. The observed and expected plots does not have much deviations and assumption of homogeneity of transition rate through the specified time are satisfied. Conclusion: The conditional probability of hypertensive patients from good states to the next worst state are decreasing over time except the first state of hypertension. Being male, older aged, living in urban, taking medication and treatments in the past, history of diabetes (between all states) had high risk of transition from state2 and state 3, state 3and state 4. Being female, younger age, living in rural, and not taking medication in the past between state 1 and state 2 were high risk of hypertension. Having family history of hypertension between state 1 to state 2, state 2 to state 3 and who were not family history of hypertension in state 3 to state 4 had high risk of transition of hypertension.V
APPLICATION OF MULTISTATE MARKOV MODEL ON THE PROGRESSION OF CHRONIC KIDNEY DISEASE PATIENTS AT TIKUR ANBESSA SPECIALIZED HOSPITAL, TASH, ADDIS ABABA, ETHIOPIA.
(HAWASSA UNIVERSITY, 2023-10) ZELALEM TOLOSA
Background: Chronic kidney disease (CKD) is a serious issue for public health. According to the WHO report for 2022, 17 million people will die from NCD diabetes (2.0 million including kidney disease deaths caused by diabetes) before the age of 70, with low- and middle-income countries providing for 86% of these premature deaths. 77% of NCD-related deaths occur in low- and middle-income countries including Ethiopia. is one of the low- and middle-income nations in the sub-Saharan region. This study was aimed to estimated the effect of covariates on progression between different stages of CKD among patients under follow up treatment at Tikur Anbessa Specialized Hospital TASH, Addis Ababa, Ethiopia, using Multistate Markov Model. Method: The study was carried out using a retrospective cohort study design on 267 CKD patients age greater than 18 randomly selected at nephrology clinic of TASH who start follow up in May 2018 up to April 2023 for five years. The five stages of CKD disease defined based on the Kidney Disease Improving Global Outcome (KDIGO) guidelines with make only forward transition among different transient stage continuously considered in the Multi-state Markov Model to estimate the transition conditional probabilities, transition intensity rate, total length of stay in different CKD patient’s stage. Result: From the total number of patients included in the study (267 CKD patients), 153 (57.3%) were males and 114 (42.7%) were females. Patients in stages 1, 2.3A, 3B, and 4 had an estimated probability of 94% (0.94), 93% (0.93), 93% (0.93), 96% (0.96), and 98% (0.98) of staying in the same stage, respectively, after one month. Estimated sojourn times for states 1, 2, 3A,3B and 4 were 16.5, 14.5, 15.5, 30.3 and 53.8 months respectively. Conclusion: Prognostic factors like being male, having a history of Diabetes, having a history of Hypertension, and having a history of heart disease were the factors that had a higher risk of progressing to severe stages in CKD patients, and Age, Haemoglobin, and Potassium were positively (or harmfully) associated with the progression of eGFR or CKD stages. Whereas Phosphate, Sodium, and Urea were negatively associated with the progression change of eGFR or CKD stages. The transition probability from a given good stage to the next worse stage increases with time, reaches its optimum (peak) at a time, and starts to decline as time goes on. stage 4 CKD had the longest estimated mean duration, followed by stage 3B, while the expected mean duration of stage 2 CKD was the shortest.
APPLICATION OF TIME SERIES ANALYSIS FOR MODELLING AND PREDICTING MONTHLY AVERAGE TEMPERATURE IN GLOBAL AND EAST AFRICA
(HAWASSA UNIVERSITY, 2024-05) NEBIYU MOHAMMED WOYESO
Global warming has garnered significant attention in recent years due to its profound implications for the environment, economy, and society. This study aims to model and forecast the monthly average temperature globally and in East Africa using time series analysis. Secondary data from the Berkeley method, spanning from 1850 to the present, were utilized. The average temperatures recorded were 14.103°C globally, 23.025°C in Ethiopia, 23.979°C in Kenya, and 23.019°C in Uganda. After applying the first seasonal differencing to achieve stationarity, statistical models such as SARIMA were employed. Based on Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC), SARIMA(4,0,0)(0,1,1,12) for global temperatures, SARIMA(2,0,2)(3,1,1,12) for Ethiopia, SARIMA(2,0,3)(0,1,1) for Kenya, and SARIMA(1,0,4)(0,1,1,12) for Uganda were identified as the best-fit models. Forecasts for the next two decades indicate an increasing temperature trend across all regions. Model performance was evaluated using metrics such as Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Mean Absolute Percentage Error (MAPE), all of which indicated good forecasting accuracy. To capture temperature volatility, ARCH/GARCH models, including ARCH, GARCH, and EGARCH, were applied. The EGARCH models were found to be most effective, with EGARCH(4,1) for global temperatures, EGARCH(3,1) for Ethiopia, EGARCH(3,2) for Kenya, and EGARCH(4,1) for Uganda showing superior performance based on lower AIC and BIC values and higher log-likelihood values. The findings have significant implications for climate adaptation planning, particularly in regions like East Africa that are highly susceptible to climate change impacts. By providing reliable forecasting tools, this study supports efforts in agricultural planning, water resource management, energy demand forecasting, public health, and environmental impact assessment.
Applied Dairy Microbiology
(Hawassa University, 2001) Elmer H. Marth; James L. Steele
ASESSMENT OF PHYSICO-CHEMICAL AND BACTERIOLOGICAL QUALITY OF DRINKING WATER SUPPLY, STATUS OF SANITATION AND HYGIENE PRACTICES: THE CASE OF BISHAAN GURRACHA TOWN, WEST ARSI ZONE, OROMIA REGIONAL STATE, ETHIOPIA.
(Hawassa University, 2024-05) MATIYAS AZAGE BETANE
Access to safe drinking water and adequate sanitation is essential for safeguarding public health. This study aimed to assess the physicochemical and bacteriological quality of drinking water supply and evaluate sanitation and hygiene practices in Bishaan Gurracha town, located in the West Arsi zone of the Oromia region, Ethiopia. The methodology involved selecting water sources and households for sample collection, employing data collection instruments including household surveys, key informant interviews, focus group discussions, and direct observations. Laboratory analyses were conducted to measure various physicochemical parameters such as pH, turbidity, TDS, EC, alkalinity, nitrates, chlorides, free chlorine, heavy metals, and bacteriological indicators including total coliforms and fecal coliform. Sanitation coverage and hygiene practices were assessed using appropriate questionnaires to ensure data suitability for statistical analyses. The results indicated that most physicochemical water quality parameters met the standard values recommended by WHO/ESA, except for temperature and turbidity. Temperature ranged from 24.33°C to 26.17°C, and turbidity ranged from 5.62 NTU to 6.73 NTU. Total coliforms were present in all water samples from source water and household storage containers, with a significant number of samples also testing positive for fecal coliforms. The mean total coliform counts varied between 18 CFU/100ml to 101 CFU/100ml for source water and 16 CFU/100ml to 81 CFU/100ml for household storage water. These findings suggest potential deterioration in the untreated drinking water distribution system within Bishaan Guracha town, as the total coliform and fecal coliform counts exceeded the recommended standards set by national and WHO guidelines. Inadequate sanitation facilities in many homes pose significant health risks to the community in Bishaan Guracha town. The absence of proper toilets and improved sanitation systems increases the likelihood of fecal contamination, leading to the transmission of waterborne diseases such as diarrhea, cholera, and typhoid fever. Immediate interventions are therefore necessary, including decontamination of water sources, repair of distribution lines, expansion of sanitation infrastructure, and increased awareness of hygiene practices. It is recommended to regularly monitor water quality and encourage community participation in sustainable water, sanitation, and hygiene services.
ASESSMENT OF PHYSICO-CHEMICAL AND BACTERIOLOGICAL QUALITY OF DRINKING WATER SUPPLY, STATUS OF SANITATION AND HYGIENE PRACTICES: THE CASE OF BISHAAN GURRACHA TOWN, WEST ARSI ZONE, OROMIA REGIONAL STATE, ETHIOPIA.
(Hawssa University, 2024-06) MATIYAS AZAGE BETANE
Access to safe drinking water and adequate sanitation is essential for safeguarding public health. This study aimed to assess the physicochemical and bacteriological quality of drinking water supply and evaluate sanitation and hygiene practices in Bishaan Gurracha town, located in the West Arsi zone of the Oromia region, Ethiopia. The methodology involved selecting water sources and households for sample collection, employing data collection instruments including household surveys, key informant interviews, focus group discussions, and direct observations. Laboratory analyses were conducted to measure various physicochemical parameters such as pH, turbidity, TDS, EC, alkalinity, nitrates, chlorides, free chlorine, heavy metals, and bacteriological indicators including total coliforms and fecal coliform. Sanitation coverage and hygiene practices were assessed using appropriate questionnaires to ensure data suitability for statistical analyses. The results indicated that most physicochemical water quality parameters met the standard values recommended by WHO/ESA, except for temperature and turbidity. Temperature ranged from 24.33°C to 26.17°C, and turbidity ranged from 5.62 NTU to 6.73 NTU. Total coliforms were present in all water samples from source water and household storage containers, with a significant number of samples also testing positive for fecal coliforms. The mean total coliform counts varied between 18 CFU/100ml to 101 CFU/100ml for source water and 16 CFU/100ml to 81 CFU/100ml for household storage water. These findings suggest potential deterioration in the untreated drinking water distribution system within Bishaan Guracha town, as the total coliform and fecal coliform counts exceeded the recommended standards set by national and WHO guidelines. Inadequate sanitation facilities in many homes pose significant health risks to the community in Bishaan Guracha town. The absence of proper toilets and improved sanitation systems increases the likelihood of fecal contamination, leading to the transmission of waterborne diseases such as diarrhea, cholera, and typhoid fever. Immediate interventions are therefore necessary, including decontamination of water sources, repair of distribution lines, expansion of sanitation infrastructure, and increased awareness of hygiene practices. It is recommended to regularly monitor water quality and encourage community participation in sustainable water, sanitation, and hygiene services.
ASSESEMENT OF THE LEVEL OF HEAVY METALS IN DIFFERENT VARIEETIES OF KHAT (CATHA EDULIS) AND SUPPORTING SOIL SAMPLES COLLECTED FROM TULLA AREA, SIDAMA REGION; ETHIOPA
(2024-11) GETAHUN MENGIST GELLA
Heavy metal pollution of the environment has been a global concern due to its acute and chronic health effects. The consumption of contaminated food and beverages is among the major route of exposure. Khat (Catha edulis) is one of the major cash crops that are widely cultivated and consumed as stimulant in the study area (Tulla Sidama regional state).This work focuses on the physicochemical analysis and determination of selective heavy metals (Cu, Co, Ni, Cr and Pb) concentration in chewable parts of the leaves of the selected Khat varieties (Nole, Dume and Megala) and its support soil samples. Samples were randomly collected from the selective kebeles of the study area and digested using mixture of acids. Analysis of the physicochemical parameters (pH, electrical conductivity and ash content) was carried out by standard method. The determination of the heavy metals was carried out using Flame Atomic Absorption Spectroscopy (FAAS). The physicochemical analysis showed pH (6.21-6.82), electrical conductivity (1.42-1.86), and ash content (1.72-2.17) in soil samples and pH (5.93-6.43), electrical conductivity (1.17-1.54), and ash content (0.63-0.93) in khat samples. The heavy metal analysis showed concentration of Cu, Ni and Co to be 4.33-4.93mg/kg, 2.52-3.26mg/kg and 1.84-2.85mg/kg respectively in khat samples. The levels of these metals in the corresponding soil samples were (8.54-9.96mg/kg), (3.67-4.95mg/kg) and (3.37-4.85mg/kg for Cu, Ni and Co respectively. Pb and Cr were not detected in soil and khat varieties samples. Among the analyzed heavy metals Cu was detected relatively at the highest concentration followed by N and Co in both soil and Khat samples. These findings indicated a positive correlation between the levels of the heavy metals in the soil and the Khat samples. Although Pb, Cr, Cu and Ni were detected below the permissible level, Co was detected above the permissible level stipulated by WHO. Therefore, it can be concluded that continuous consumption of Khat as stimulant might lead to health risks associated with heavy metals.