https://repository.maseno.ac.ke/handle/123456789/1307 2026-05-15T14:17:04Z https://repository.maseno.ac.ke/handle/123456789/6452 Epidemiological and genetic analysis of quantitative resistance to gray leaf spot (cercospora zeina) in elite maize (zea mays l) genotypes NYANAPAH, James Osare Maize has a significant and increasingly crucial role in global food security systems, but the threat of gray leaf spot (GLS) disease, caused by Cercospora zeina, persists and continues to impact its yields on a global scale.Forty-eight inbred lines of maize from the International Maize and Wheat Improvement Center (CIMMYT)were sorted into 6 sets and factorial crosses of each set generated according the North Carolina mating design II. The lines alongside their crosses evaluated across 12 environments to characterize partial disease resistance to artificial GLS epidemics,temporal progress of the disease, genetic association of resistance with 9 phenological traits, and combining abilities alongside heterotic effects of the inbred lines for resistance. Eight measures of resistancethat includedstandardized area under disease progress curve (SAUDPC), and weighted mean absolute rate of disease increase (ρ) were examined. SAUDPCs were the most efficient infection measure, buttheir variability were best explained (R2 = 93.9%) by disease ratings between the VT (full tassel emergence preceding pollen shed) and R4 (dough stage) stages of development. Individual disease ratings at R4 were almost as effective as SAUDPCs in characterizing genotype reactions.The Levenberg-Marquardt algorithm, along with integration of data eyeballing and gridding to determine starting parameter values, were the best methods for estimating the nonlinear regression model that accurately fit the gray leaf spot (GLS) epidemics.The generalized version of the Richards model outperformed all other growth curve models examined except in some instances where its curve shape parameter matched the fixed curve shape models that best fit any particular epidemic. Goodness of fit of the monomolecular, Gompertz, logistic and exponential models varied with the resistance of entries and favorability of the trial environments to GLS development. Genotypic and phenotypic correlations of SAUDPC were strongest with the Stay-green characteristic (SGR) (r = −0.87). The magnitude and direction of coheritability estimates mirrored trends in genotypic and phenotypic correlations. The covariation of GLS resistance with agronomic traits was mainly due to the direct effects of days to anthesis (DTA) and days to silking (DTS), and the indirect effects of stay-green capacity (SGR) and silking-maturity interval (SMI). General combining ability (GCA) and specific combing ability (SCA) effects were significant. However, the GCA effects were more important than SCA effects signifying the preponderance of additive gene action. Although this was confirmed by significant correlations between GCA effects and per seresistance of inbred parents, the correlations were not strong enough to be of predictive value. Estimates of potence ratio suggested that non-additive effects were due to multiple loci and alleles with recessive, dominance, over-dominance, and various types of epistasis. These findings indicate that comparative analysis of GLS epidemics should be based on the generalized Richards model and breeding for resistance should prioritizereciprocal recurrent selection, pedigree selection, restricted index selection, multiple population improvement, and multistage selection depending on the genetic background of the sources of resistance. PhD Thesis 2025-01-01T00:00:00Z https://repository.maseno.ac.ke/handle/123456789/6444 Mental health literacy and its influence on mental well-being and help-seeking attitudes among secondary school students in Homa bay county, Kenya ACHIENG, Monica Anne Oyoo The World Health Organization (WHO) estimates that one in four Kenyans experiences a mental health problem, with depression and anxiety symptoms being the most prevalent. Among secondary school students, prevalence of depression and anxiety symptoms are 28.1% and 38% nationally. Prevalence of depression symptoms among students is 44.8% in Kakamega County while Kisii and Migori Counties record 23% and 23.6% respectively. In Homa Bay County, these rates are notably higher, at 57.5% for depression and 49.4% for anxiety. Such figures highlight the urgent need for interventions given the academic, social, and health implications of untreated mental health conditions. Previous studies suggest that enhancing Mental Health Literacy (MHL) can improve well-being and promote positive help-seeking behaviour. The purpose of the study therefore was to examine the influence of MHL on mental well-being and help-seeking attitudes of secondary school students in Homa Bay County, Kenya. Objectives of the study were to: evaluate levels of MHL, assess the nature of relationship between MHL, mental well-being and help-seeking attitudes; establish moderation effect of availability of school-based mental health resources and gender in the relationship between MHL, mental well-being and help-seeking attitudes and establish interventions that can be put in place to improve levels of MHL among students in secondary schools in Homa Bay County. The study was anchored on Health Belief Model, Social Cognitive Theory and a conceptual framework showing the interaction between MHL (independent variable), mental well-being and help-seeking attitudes (dependent variables). Descriptive, correlational and quasi-experimental research designs were employed. The study population was 131,749 students from form1 (F1) to form 4 (F4). Stratified random and purposive sampling were used to select 400 respondents using Yamane’s formula. Data were collected using questionnaires and focus group discussions (FGDs). A pilot study was conducted among 30 students. Reliability of the instruments was established using test–retest method, with Pearson’s correlation and Cronbach’s alpha were used to determine the reliability coefficients. The results were as follows: MHL Scale (r̄ = .78, α = .98), General Help-Seeking Questionnaire (r̄ = .89, α = .99), Questionnaire on interventions (r̄ = .74, α = .98), General Anxiety Disorder (GAD-7) (r̄ = .88, α = .98) and Depression Assessment Questionnaire (DAQ-9) (r̄ = .91, α = .99). Face and content validity of the instruments were ascertained by experts in the area of Educational Psychology. Quantitative data was analyzed using means, percentages, Pearson’s r, independent samples t-test, ANOVA and linear regression analysis. Qualitative data was transcribed, categorized and reported thematically. Results showed that levels of MHL was moderate (M = 42.84, SD = 5.80), levels of MHL positively correlated with mental well-being r(382) = .822, p = .00 and attitudes towards help-seeking (r(382) = .102, p = .046); The moderating effect of school-based resources was statistically non-significant for mental well-being (R = .534, R² = .285, Adjusted R² = .279,F(3, 373) = 49.569, p < .001, Durbin–Watson = 2.134) and help-seeking attitudes (R = .223, R² = .050, Adjusted R² = .042, F(3, 373) = 6.530, p < .001, Durbin–Watson = 1.924). Moderating effect of gender was also statistically insignificant for mental well-being (R = .534, R² = .285, Adjusted R² = .280, F(3, 378) = 50.326, p < .001, Durbin–Watson = 2.126) and help-seeking attitudes (R = .132, R² = .017, Adjusted R² = .010, F(3, 378) = 2.220, p = .085, Durbin–Watson = 1.962). MHL programme was the most effective (M = 3.52, SD = .65) and use of school computers the least effective (M = 2.71, SD = .89). It was concluded that levels of MHL were moderate, MHL positively correlated with both mental well-being and help-seeking attitudes; interaction effect of availability of school-based mental health resources and gender were non-significant. MHL programme was the best strategy to improve MHL. It was recommended that schools teach MHL and make mental health resources accessible to improve MHL and help-seeking attitudes among students. Findings of this study are expected to inform development of policies to improve levels of MHL and mental well-being among students in secondary schools. PhD Thesis 2025-01-01T00:00:00Z https://repository.maseno.ac.ke/handle/123456789/6437 Urban food systems and the spatial planning regime in Kakamega municipality, Kakamega County, Kenya SHIKOLI, Sammy Shileche Rapid urbanization has resulted in tremendous transformation in urban system dynamics. In particular, urban areas are increasingly experiencing food shocks and stresses that have affected their resilience ability, leading to challenges in food availability and access. Currently, urban areas occupy only 2% of the earth surface but consume more than 70% of the global food supply. Without intervention, consumption will increase and possibly surpass existing food supplies. This necessitates the establishment of sustainable and resilient urban food systems. Over the past decade, food systems planning has blossomed into a central concept in urban planning. Planners have gradually realized that they cannot achieve sustainable urban development unless the urban food system is integrated into the urban planning framework. The question however remains how to affect this integration. Kakamega is one of the fastest growing municipalities in Kenya, with the majority of households perennially affected by food insecurity. With a population growth rate of 2.5%, food demand and consumption rate will escalate in the near future. Yet it is not known how, or if at all, the urban food system dovetails into the extant municipal planning framework. How, for instance, does the planning regime (re)produce Kakamega’s food system? This study therefore sought to examine the structures and level of integration of Kakamega’s urban food system into the municipal planning framework. Specifically, the study aimed at examining the extant urban planning processes; analysing components of the local urban food system; and strategies of integration between the urban food system and urban planning in Kakamega Municipality. The study is anchored on the Food Supply Distribution System (FSDS) model. The study applied a cross-sectional design. The data sources were primarily from first hand interaction with respondents, observation and literature reviews. A sample survey of 382 households derived by the Morgun formula from a total of 52,015 households spread across the eight municipal wards was considered. A sample size of 175 market retailers (25 retailers from each of the 7 markets) was also interviewed. Four focused group discussions were held with food retailers, a youth group, meat suppliers and university students. Besides, key informant interviews were held. Officers in key departments dealing with policy and functions in urban planning and urban food systems namely County directors of Urban Planning, Agriculture, Trade, Finance and Economic Planning departments, as well as with the Municipal Planner, market superintendents and ward administrators were purposely sampled and interviewed. Field-based observations were also conducted. Qualitative data was analysed thematically, while quantitative data was summarised and reported by mean, mode and variance. The findings indicate that the local planning policy and regulatory framework is at variance with the quotidian practice on the ground. Furthermore, the municipal food system as currently practiced is informal, unstructured and unstable, determined as it is by the vagaries of demand and supply forces. While there is some level of integration between the local food system and the extant urban planning framework, this remains rather weak and hence unable to guarantee food resilience for long-term urban sustainability. In the upshot, the study recommends that the urban planning framework be strengthened by formulation of the urban development control guidelines to regulate developments. The Municipal board to increase budgetary allocation for urban planning framework, empower the planning team by increasing more staff since we only have one Municipal planner. The Municipal planner as an urban manager to introduce policies in the planning framework that promotes food production in urban areas, such as reservation of agricultural land, limit on bylaws that restrict urban agriculture and reduce taxes on urban agriculture practices. The food system be formalized and documented by the Municipal manager. That the captured data be processed and accessible to all stakeholders in the municipal food system. More emphasize on food production rather than depending on food imports. It is proposed that the necessary synergies be build capitalizing on the prevailing slight integration between the urban food system and the planning framework in order to eliminate the current tendencies of the two entities functioning in isolation, and often at cross-purposes. PhD Thesis 2025-01-01T00:00:00Z https://repository.maseno.ac.ke/handle/123456789/6434 Response and coping mechanisms that shape social resilience to flood disasters in Nyando river basin of Kisumu county, Kenya ONYANGO, Silvance Ochola Floods form the most frequent natural disaster phenomena, accounting for approximately 47% of all weather-related worldwide dangers, and occasioning annual loss of life and property to over 250 million people. Kenya’s Nyando River Basin has continued to experience chronic flood disasters over the years, affecting 85% of households and accounting for over 70% of such hazards in the country. While flood-related losses have been widely documented, focus on how locally available social and cultural resources that might help local communities to enhance their resilience during such disasters has been limited. The objective of this study was to analyse the response and coping mechanisms shaping social resilience to flood disasters in Nyando River Basin of Kisumu County, Kenya. Specific objectives were to: determine how culturally-based environment conservation practices help in responding to flood disasters; analyse how collective actions have helped in responding to flood disasters; and to establish how preparedness informed by local forms of weather prediction help in responding to flood disasters in the Nyando River Basin of Kisumu County, Kenya. The study was guided by social resilience theory which highlights people’s capacity to respond, cope, and recover from disasters. This study utilized cross sectional descriptive survey with a mixed-methods approach on a target population of 1,728 households. Yamane’s formula was used to compute a sample size of 324 households that were interviewed using a semi-structured questionnaire. Key informant interviews and focus group discussions were used to gather information from officers from the Ministry of Interior (the chiefs and their assistants), Community Based Organizations (CBOs) operating in the study area, local community health workers, community elders (headmen), and local disaster committee members. The quantitative data was analyzed using descriptive statistics (Mean, standard deviation, and frequencies), and the qualitative data was analyzed using thematic analysis. Findings showed that culture-based environment conservation practices such as protection of sacred trees, water resources and waterways have occasionally been relied upon to respond to flood disasters, although a number of cultural environmental practices previously observed have been eroded leading to diminishing of tree cover and in turn contributing to continuous flooding. Similarly, collective action enhanced by use of social media platforms has been occasionally relied upon to provide significant support during flood disasters. In addition, movement of cloud especially appearance of dark clouds over the Nandi Hills (Gablilo) is a precise indication of a looming flood disaster in the area, and this arouses various measures for mitigating its impacts. The study concludes that erosion of cultural and social mechanisms is exposing the people to the negative impact of floods in the area. To cement cultural conservation practices, support in terms of provision of various indigenous trees and plants for planting along waterways so as to enhance protection of riparian lands is recommended. Similarly, collective entities such as family institutions should be strengthened to play a critical role in recovery during and after flood disasters. Additionally, immediate warning systems should be prompted immediately predictive signs are sited along the Nandi escarpment, the Gablilo, to enable adequate preparedness to save property. More research should be done to shed light on ow indigenous response mecanisms to flood disasters enhance growth social resilience among households in the Nyando River Basin of Kisumu County, Kenya. PhD Thesis 2025-01-01T00:00:00Z https://repository.maseno.ac.ke/handle/123456789/6433 Genomics and metagenomics analysis of non-typhoidal salmonella from children below five years and their immediate environment in disease-endemic Mukuru settlement in Nairobi, Kenya KEBENEI, Collins Kipkorir Non-typhoidal Salmonella (NTS) remains a leading cause of morbidity and mortality in Sub-Saharan Africa, particularly among vulnerable children within informal settlements where safe water, sanitation, and hygiene (WASH) infrastructure are inadequate. The rising prevalence of antimicrobial-resistant NTS strains and the role of household environments as potential reservoirs sustaining endemic transmission remain poorly characterized in these high-risk informal settlements. This study aimed to investigate the occurrence, genetic diversity, antimicrobial resistance, pathogenic potential, and spatial distribution of NTS strains from environmental and clinical sources within Mukuru informal settlement, Nairobi, Kenya. By linking clinical and environmental NTS strains, the study provides insights into the persistence and transmission of antimicrobial-resistant strains. A case-control study conducted between June 2021 and June 2023 analyzed 2,675 clinical samples from children and 268 environmental samples, including drinking water, effluent, soil, and raw sewage, collected from case and control households. NTS isolation from clinical samples was performed using standard microbiological and biochemical techniques, followed by confirmation and serotyping through serological assays and whole-genome sequencing. Environmental samples underwent metagenomic sequencing and binning of NTS genomes. Whole-genome and metagenomic sequences were analysed to characterize genetic diversity, antimicrobial resistance genes (ARGs), and pathogenicity determinants. Core-genome SNP-based phylogenetic reconstruction assessed genomic relatedness, while spatial analyses mapped transmission patterns over time. NTS was detected in 1.57% of clinical samples, predominantly Salmonella Enteritidis (52.4%) and Salmonella Typhimurium (47.6%). Environmental samples from case households exhibited higher detection rates of NTS (33.3%) than those from homes of controls (7.1%), with effluent (45.2%) and drinking water (33.3%) showing the highest contamination levels. Core-SNP phylogenetic analysis revealed strong genomic relatedness between clinical and environmental NTS strains within households (F = 0.8171, R² = 0.0496, p = 0.459), affirming intra-household environmental-human transmission cycles. Effluent-derived strains often occupied basal phylogenetic positions, implicating household wastewater as a potential ancestral source. Antimicrobial resistance profiling revealed aminoglycoside resistance genes as the most prevalent across clinical and environmental NTS strains, with aac(6’)-Iaa_1 detected in 100% of clinical and 97.6% of environmental strains. Additional resistance genes included aph(6), aph(9)-Ia, oqxA, sul_1, cat2, and blaTEM-104_1. Notably, aph and oqxA genes were co-located within conserved resistance cassettes embedded in IncFIB(S)_1 and IncFII(S)_1 plasmids. These cassettes were flanked by mobile genetic elements, IS3, IS15, IS256, ISPm12, and transposons Tn3 and TnAs3, forming modular, horizontally transferable resistance islands. Pairwise comparisons revealed overlapping ARG profiles within household-case clusters, suggesting intra-household environmental-to-human ARG spillover (F = 1.816, R² = 0.131, p = 0.062). IncFIB(S)_1 (97.2% clinical, 29% environmental) and IncFII(S)_1 (97.2% clinical, 31.6% environmental) plasmids, harboring compact Type IV secretion systems, were the dominant replicons across clinical and environmental strains, suggesting high conjugation potential and ecological persistence. PERMANOVA revealed significant differences in plasmid profiles between clinical and environmental compartments (p_adj=0.01), except raw sewage (p_adj=0.154). Virulence gene profiling showed substantial overlap between clinical and effluent, drinking water, and soil NTS strains, with significant differences only between clinical and raw sewage strains (F=10.625, R²=0.202, p_adj=0.05). Spatial analysis revealed that high-intensity hotspots were consistently mapped to areas of infrastructural deficiency. These spatial patterns suggest that environmental matrices serve as reservoirs for antimicrobial-resistant NTS, underscoring the need for targeted WASH improvements and routine One Health surveillance to interrupt transmission in informal settlements. PhD Thesis 2025-01-01T00:00:00Z https://repository.maseno.ac.ke/handle/123456789/6430 Athari ya vivumishi vya Runyakitara kwa ujifunzaji wa kiswahili katika shule za upili jijini Mbarara, Uganda KARUHANGA, Deusdedit Katika mfumo wa elimu nchini Uganda, Kiswahili ni lugha muhimu kwa mawasiliano na maendeleo ya kijamii. Hata hivyo, wanafunzi wanaozungumza Runyakitara wanakabiliwa na changamoto mbalimbali katika ujifunzaji wa Kiswahili, hasa katika matumizi ya vivumishi. Changamoto hizi zinatokana na tofauti za kimuundo na kimaana baina ya vivumishi vya Runyakitara na vivumishi vya Kiswahili, hali inayopelekea makosa ya kiisimu katika mchakato wa ujifunzaji. Wanafunzi ambao lugha yao ya kwanza (L1) ni Runyakitara moja ya lugha za Kibantu zinazoenea Kusini Magharibi mwa Uganda, hukumbana na changamoto mahsusi wanapojifunza Kiswahili kama lugha ya pili (L2). Kwa hivyo, utafiti huu ulichunguza athari za vivumishi vya Runyakitara katika ujifunzaji wa Kiswahili.Utafiti huu uliongozwa na malengo maalum: Kubainisha tofauti za kimuundo kati ya vivumishi vya Runyakitara na Kiswahili, Kuchunguza athari za vivumishi vya Runyakitara katika ujifunzaji wa Kiswahili, na Kutathimini makosa ya kiisimu yanayotokana na uhamishaji wa vivumishi vya Runyakitara kwenye ujifunzaji wa Kiswahili. Utafiti huu uliongozwa na Nadharia ya Uchanganuzi Linganuzi (contrastive analysis), ambayo ilianzishwa awali na Fries, Weinreich, Haugen, na Lado (1950), kisha ikaendelezwa na James (1980) na Jean (2022). Mihimili muhimu ya nadharia hii iliyotumiwa ni: mfanano na tofauti za lugha, uingiliaji wa lugha ya kwanza (L1), uhamishaji chanya na hasi, na utambulisho wa makosa. Nadharia hii ilitumika kuchanganua athari za vivumishi vya Runyakitara katika ujifunzaji wa Kiswahili sanifu. Muundo wa kimaelezo ulitumika katika utafiti huu, ambao ulifanyika katika Jiji la Mbarara, Uganda, ukilenga taaluma ya isimu linganishi. Idadi lengwa ya utafiti ilikuwa wanafunzi 100 wanaosoma Kiswahili katika shule 10 za sekondari jijini Mbarara. Washiriki hawa waliteuliwa kwa kutumia mbinu mseto: usampulishaji wa nasibu ulitumiwa kutambua shule10 zinazofundisha Kiswahili na usampulishaji wa kimaksudi ulitumiwa kuteua wanafunzi ambao lugha yao ya kwanza ni Runyakitara kutoka kwenye shule hizo na vitabu vya sarufi vya Runyakitara na Kiswahili. Data ya nyanjani ilikusanywa kwa kutumia mjarabu wa kimaandishi na mjarabu wa kimazungumzo kutoka kwa wanafunzi, huku data ya maktabani ikipatikana kupitia uchambuzi wa matini kwenye vitabu vya sarufi vya Runyakitara na Kiswahili. Zana zilizotumika ni Kifaa cha Mijarabu ya Kiisimu, kifaa cha kinasa sauti, kifaa cha orodha ya uchunguzaji wa miundo ya vivumishi yenye sifa za Kimofolojia. Data iliyokusanywa ilichanganuliwa na kuwasilishwa kwa mbinu ya kimaelezo, ikishirikisha majedwali na michoro ili kuonyesha miundo, athari, na makosa ya kiisimu ya vivumishi vya Runyakitara katika ujifunzaji wa Kiswahili. Matokeo ya utafiti yalilingana na malengo yake matatu: ilionekana kwamba vivumishi vya Runyakitara na Kiswahili vinafanana katika baadhi ya vipengele vya kimofolojia lakini hutofautiana kimsingi katika upatanishi wa kisarufi na mpangilio wa maneno. Pili, vivumishi vya Runyakitara huathiri ujifunzaji wa Kiswahili kwa kuhamishwa moja kwa moja, na kusababisha makosa ya kimuundo na kisintaksia, tatu, makosa ya mwanafunzi yalibainika zaidi katika uhusishaji wa kivumishi na nomino, matumizi ya viambajengo vya kivumishi, na mfuatano wa vivumishi. Kwa hivyo, utafiti ulibaini kuwa ingawa Runyakitara na Kiswahili ni lugha za nasaba moja ya Kibantu, tofauti za kimuundo na matumizi ya vivumishi zinawapa wanafunzi changamoto kubwa katika kujipatia Kiswahili L2. Utafiti huu unahimiza maendeleo ya mbinu bora za ujifundishaji lugha, unasaidia watunga mitaala kuelewa mapungufu ya wanafunzi, na unapanua mijadala ya kitaaluma kuhusu ujifunzaji wa lugha ya pili kwa muktadha wa lugha zinazokaribiana. PhD Thesis 2025-01-01T00:00:00Z https://repository.maseno.ac.ke/handle/123456789/6429 Culturable soil microbial community structure, nutrient dynamics and greenhouse gas emissions in Maize-Banana Based agroforestry system in Kisii County, Kenya BUYELA, Daniel Khasabulli Microbial community structure are the characteristics of a group of microorganisms as measured by any metric of taxa or gene composition, diversity and abundance via a range of molecular or cultural techniques. Soil microbial community structure is an important biological component of soil function. Microbial community affect the belowground dynamics and fate of nutrients which can influence soil fertility. Soil microorganisms play a significant role in the efflux of greenhouse gases (GHG). To better comprehend agroforestry systems that can enhance soil nutrients and combat climate change, it is vital to ascertain the effects of agroforestry systems (AFS) on the soil microbial community structure. Declining soil fertility as a result of continuous cropping is a major problem facing farmers in Kisii County. The link between the microbial community and GHG emissions remains poorly understood due to the diversity and complexity of microorganisms in soils. Further, there is little understanding of the morphological and molecular characteristics of these microbes. There is paucity of information on the role of microbes on soil nutrient dynamics and greenhouse gas efflux in maize-banana based AFS in Kisii county. For smallholder farmers to adapt agroforestry systems for their potential to increase soil fertility and reduce GHC emissions, there is a dearth of simple methodologies. Therefore, the objective of this study was to assess soil microbial community structure, nutrient dynamics and greenhouse gas emissions in a maize-banana based agroforestry system in Kisii County. This study was conducted at Kenya Agricultural and Livestock Research Organization farm in Kisii County. This study was conducted on an established agroforestry experimental plots which were set using a completely randomized block design with maize and banana intercropped with agroforestry trees. Soil samples were taken randomly at 10 different spots per plot at a depth of 0-15cm. Soil microbial biomass was determined using the chloroform fumigation extraction and their population determined by direct counting. Microbes were isolated in pure cultures, characterized morphologically and molecularly, and their phylogenetic relationships determined. Total organic carbon(C), nitrogen(N), phosphorus(P), potassium(K), calcium(Ca) and magnesium(Mg) were determined. Soil GHG (carbon dioxide, methane, and nitrous oxide) measurements were done using closed chambers. Soil pH was determined using a combined pH meter. Morphological and molecular data was subjected to cluster analysis. Data was subjected to analysis of variance and means separated using Least Significant Differences (P ≤ 0.05) after testing for normality. Correlation analysis was carried out on soil microbial biomass, microbial populations, soil carbon, nutrients and GHG. Microbial biomass and population were significantly higher in intercrop treatment with maize-banana, Sesbania sesban (MBSS). Most of bacterial isolates were Gram-negative bacilli and cocii with a few Gram-positive bacilli belonging to thirteen genera, while fungal isolates belonged to seven genera. Bacteria isolates clustered into five orders and fungal isolates clustered into three orders. Morphological genograms clustered isolates in two groups at 75% similarity level. Molecularly, sequences of bacterial isolates had >97% similarity match with gene bank isolates except MBCC2 while all fungal isolates had >97% similarity match with Genebank isolates. Soils from agroforestry tree species combinations treatment MBSS had higher values of C, N, P, K, Ca and Mg levels. Plots with Calliandra calothyrsus agroforetry tree species had low values GHG emissions. Sesbania sesban has the ability to increase soil microbial biomass and population which in turn act to improve soil health through microbial organic matter decomposition and thus recommended for use in maize-banana based agroforestry system. The study recommends the use Calliandra PhD Thesis 2023-01-01T00:00:00Z https://repository.maseno.ac.ke/handle/123456789/6428 Influence of climate variability and land use land cover change on the hydrology and sediment yield in upper Ssezibwa catchment, Uganda MWANGU, Alex Ronald Climate variability and Land Use Land Cover (LULC) change influence hydrology and Sediment Yield (SY) in catchments. Globally, over 60 percent of the ecosystem is degraded, over 83% of the terrestrial land surface has been affected by anthropogenic activities over the last fifty years while more than 85% of the area covered by wetlands has been lost since 1700. Variation in rainfall and temperature combined with LULC change have altered the natural habitat, surface runoff (SURQ) and SY leading to siltation of rivers and floods resulting into destruction of property up on the lower part of upper Ssezibwa catchment. This study aimed at assessing the influence of LULC change and climate variability on hydrology and sediment yield in upper Ssezibwa catchment. The specific objectives were to; examine the influence of LULC change on river discharge and SY from 2002 to 2022; determine the influence of variation of interannual rainfall and temperature on river discharge and SY; establish the influence of LULC changes on river discharge and SY for the period 2022-2052; and to assess influence of future variations in rainfall and temperature on river discharge and SY for the period 2022-2052 using SWAT model. The study was anchored in the General Systems Theory that postulates that a morphological/drainage system is composed of different components that are interrelated and an effect on one element affect the entire system. The study used quasi-longitudinal and correlational research designs. Digital Elevation Model, Landsat 7 ETM+ images, meteorological and hydrological data were used. Pearson Correlation Coefficients and Regression analysis were used for data analysis. SWAT model calibration on observed streamflow data (R2=0.85, NSE=0.82, KGE=0.76, PBIAS = -18.5) and validation (R2=0.72, NSE=0.66, KGE=0.66, PBIAS= -19.3) indicate the model is acceptable. Overall accuracy assessment of over 80% and Kappa statistics of 0.82, 0.84 and 0.80 for the years 2002, 2012 and 2022 respectively were satisfactory. Results indicate that LULC change has a statistically significant influence on SURQ, Lateral flow (LATQ), groundwater flow (GWQ), deep aquifer recharge and SY (p = .000, α=0.05). Rainfall has a statistically significant relationship with both discharge and sediment yield (p=0.013, α=0.05) for 2002-2012. Projections indicate that the future LULC change has a statistically significant influence on discharge and SY (p = .000, α=0.05). Projections further indicate that variation in temperature and rainfall for the period 2022-2052 is likely to influence discharge and SY (p = .000, α=0.01) under RCP 4.5 and RCP 8.5 scenarios signaling future flooding within the catchment. The study concludes that LULC changes and climate variability have influenced river discharge and sediment yield in converse proportions in upper Ssezibwa catchment. The study recommends that the central and local governments should enhance the amount of forest cover through afforestation and reforestation initiatives to enhance the ability of the catchment to retain water and controlling sediment loading and surface runoff. In addition, the government should provide public education and awareness about environmental conservation, while watershed protection must be incorporated into development planning. PhD Thesis 2025-01-01T00:00:00Z https://repository.maseno.ac.ke/handle/123456789/6426 Factors associated with drug resistance patterns among antiretroviral therapy-experienced adolescents in south rift valley, Kenya ODHIAMBO, Argwings Miruka Even though antiretroviral (ART) has greatly improved survival of people living with HIV, resistance mutation is an emerging threat to scale up of ART globally. Adolescents have higher risk of drug resistance mutations (DRM). Factors associated with DRM in South Rift Valley remain unknown. The objective of study was to investigate factors associated with DRM among ART-experienced adolescents aged 10-19years enrolled in Nandi, Kericho, Bomet, and Narok counties. Specifically, study aimed to characterize HIV drug resistance patterns, assess biomedical; behavioral; and determine health systems factors associated with DRM. This cross-sectional cohort study comprised of 226 participants selected through simple random sampling using mixed method conducted between August-November 2024. Data on DRM was extracted using standardized tool and interpreted using Stanford HIVDR database. Questionnaires and interview guide used to collect data on biomedical, behavioral and health systems factors. Descriptive statistics, Chi-square test, and bivariate and multivariate logistic regression performed to examine association between variables and DRM. Quantitative data analyzed using SPSS Ver.27, with statistical significance set at p ≤ 0.05 while qualitative data used NOVO approach. Overall, 145 (64%) adolescents exhibited resistance. Mean age 16.3 years (SD = 2.7); 51.3% male and 65% orphans. Dual resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) and nucleoside reverse transcriptase inhibitors (NRTIs) occurred in 53%, while resistance to protease inhibitors (PIs) and integrase strand transfer inhibitors (INSTIs) was 9.3% and 7.1%, respectively. NNRTIs, resistance was highest to NVP (50.4%) and EFV (49.6%), commonly driven by K103N (23.9% and 28.8%). NRTI resistance included 3TC (40%, M184V 31%), AZT (20%, M184V 5.8%), ABC (26.3%, M184V 13.3%), and TDF (2.7%, M184V 1.8%). PI resistance featured ATV/r (V82A, L33F), DRV/r (L89V), and LPV/r (V82A). INSTI resistance included DTG, CAB, and RAL with S230R, G118R, R263K, and Y143R mutations. Bivariate analysis revealed factors associated with DRMs include duration on ART (p = 0.030), number of enhanced adherence counseling EAC sessions (p = 0.001), ART regimen type (p = 0.001), CD4 count (p = 0.030), caregiver occupation [p = 0.029], and orphan status [p = 0.049]. Multivariate logistic regression, ART duration, ART regimen, and EAC sessions associated with drug resistance. Longer ART duration, EAC sessions, and use of NNRTI-based regimens were associated with DRM. Thematic analysis suggests adherence among adolescents is shaped by both individual motivation and by social, family, and systemic factors. Participants suggested that empowering caregivers through education on ART adherence, HIV literacy, and adolescent development could foster a more supportive home environment PhD Thesis 2025-01-01T00:00:00Z https://repository.maseno.ac.ke/handle/123456789/6422 Effects of land use land cover changes on land quality in Khwisero sub county, Kakamega County, Kenya MUTENYI, Petronillah Shumila Land use land cover changes (LULCCs) have to a great extent, changed the world's landscapes, rebuilding environments and what they provide to humans during the time spent supporting the rising population across the globe. However, the LULCCs affect land quality in terms of loss of vegetation cover and alteration of soil quality. Misango Hills natural forest and other forms of vegetation cover types in Khwisero Sub County have been subjected to LULCCs and changed over to farming and built-up regions. Conversion of land into settlement and urban areas in the study area has led to depletion of essential soil nutrients and a decline in soil pH, affecting agricultural activities. The factors driving these changes differ from one location to another, resulting in varied effects that in turn have significant implications on vegetation cover type and soil quality, particularly soil nutrients, moisture, and temperature. Notably, no clear investigations have been done in the study area on these varied effects that challenge land quality’s fundamental design and functional capacity. Therefore, the purpose of this study was to examine the effects of LULCCs on land quality in Khwisero Sub County, Kakamega County. The specific objectives of this study were to; examine the driving forces that influence land use land cover changes, determine the effects of land use land cover areal changes on vegetation cover types, assess the effects of land use land cover areal changes on soil nutrient availability (pH, NPK and SOM) and determine the effects of land use land cover areal changes on soil moisture levels availability and soil temperature. This study adopted the land rent tenet of Von Thunen's agricultural land use theory, Alonso's bid rent theory, and Ricardian economic theory. Multiple research designs (cross-sectional descriptive, longitudinal, and experimental) were used. Purposive sampling was used to select the key informants. Spatial random sampling was used to identify soil sampling points. A random sampling technique was used to select a minimum sample size of 384 respondents from a study population of 113,476. A supervised classification algorithm and a post-classification comparison change detection were used to measure land use land cover (LULC) percentage area change over time. Primary data was collected through questionnaires, key informant interviews, field observations, field measurements, and laboratory procedures. Secondary data involved downloading Landsat images (Landsat 7, 8, and 9; 30-meter multispectral), journal articles, annual reports, and the internet. Quantitative data analysis involved measures of central tendency, measures of dispersion, analysis of variance (ANOVA), and regression. Qualitative data was analysed by organizing it into patterns and themes relevant to the current study. LULCC drivers were analysed through a sensitivity analysis. The current study revealed four land use land cover classes of agriculture, forest, built up, and bare land. Accuracy assessment for the land use land cover classes for 2002 was 85.45% with a Kappa coefficient of 0.756, 2012 was 83.64% with a Kappa coefficient of 0.5454, while 2023 was 81.82% with a Kappa coefficient of 0.6034. The findings revealed that LULCCs are driven by settlement, poverty, and climate change, mostly affecting cropland, vegetation, and soil fertility. In addition, LULCCs affected all the vegetation cover types and soil fertility due to the decrease of NPK, SOM, SMC, an increase of soil temperatures, and a shift from moderate alkaline soils to moderately acidic and highly acidic. About 26.8% and 11.3% of the variance of SOM (R2 = 0.268, p<0.001) and TK (R2 = 0.113, p<0.046), respectively, can be explained by NDVI. About 67.1% of the variance of pH (R2 = 0.671, p<0.000) can be explained by SI, while about 47.5% variance of SMC (R2 = 0.475, p<0.000) can be explained by SMI. The stepwise Multiple Linear Regression Model of NDVI and NPK together with SOM revealed that about 26.8% variance of SOM (R2 = 0.268, p<0.001) could be explained by NDVI amongst the variables in the model. About 33.6% and 32% variance of SMC (R2 = 0.336 and 0.320, p<0.000) could be explained by soil pH amongst all the variables in this model. The current study concluded that drivers of LULCCs vary from place to place, affecting vegetation types, soil nutrients, soil moisture, and soil temperature, key determinants of land quality. The study recommends the creation of awareness among the local community for a better understanding of the importance of land quality, specifically soil nutrients of NPK, SOM, SMC, pH, and soil temperature. A review of the forest policy, particularly on reafforestation, would save vegetation cover, while the soil management policy should incorporate free soil testing for locals, educating them on methods of improving the already damaged soils in Khwisero Sub County. PhD Thesis 2025-11-13T00:00:00Z