Masters Theses and Projects

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An Interaction model between Cotesia flavipes and Cotesia sesamie, Parasitoids of the gramineous stem-borers at the Kenya Coast
(Kenyatta University, 2002) Karuku, Simon
One of the greatest challenges facing the people of sub-Saharan Africa is the production of sufficient food to feed a rapidly increasing population in the face of dwindling finances. As the population grows at 3% and food production at 2% per annum, an annual shortage of 250 million tons of food is expected by year 2020. The greatest obstacle to increasing the production of maize and sorghum, the staple food in many African communities south of the Sahara, is damage by phytophagous insects. Larval feeding in the plant Whorl and later through stem tunneling causes plant damage. Infested plants have poor growth and reduced yield and are more susceptible to secondary infection and wind damage. Estimates of yield losses due to stem-borer are in the neighborhood of 20-40% of the potential yield. To realize the potential of the Gramineae family in ensuring food security in the world, the stem-borers have to be effectively controlled. Various methods have been tried in a bid to control these pests. In biological control, one of the approaches is to find an exotic natural enemy that will successfully fit into the community of existent natural enemies. Hampered by a lack of economic and convenient tools, however, advances in biological control have been largely overshadowed by the rush to exploit insecticides and the ready availability and comparative simplicity of cultural methods. But that is changing. Effects on non-target organisms, resistance development and environmental pollution have incapacitated insecticides and other chemical-based methods. In this study, a simple one host-two parasitoids interaction model with a non-linear trend is developed to predict and understand the reasons for the ultimate impact of the exotic parasitoid Cotesia flavipes (Cameron) (Hymenoptera Braconidae) on stem-borer population dynamics in the coastal area of Kenya. Results indicate that the ultimate extent of suppression of the stem-borers is largely determined by three attributes of the parasitoids namely; the net reproductive rate, the degree of aggregation and the searching efficiency. The model predicts coexistence of all the species considered with C. flavipes dominating the interactive system. Implications of the results for introduction scheme of parasitoids to control pest are discussed. We argue that a model of intermediate complexity may offer the pest prospects of predictive biological control in situations where it is not practicable to obtain the information needed to build and parameterize a large tactical simulation model. The conclusions we reach are of relevance to classical biological control practices, and in particular to those programs in which more than one parasitoid species has been introduced to combat a particular pest of a perennial standing crop system.
Low Cost Pozzolana based Cement from Industrial and Agricultural Waste Materials
(Kenyatta University, 2003-09) Wachira, Jackson M.
This thesis reports the results of a study aimed at making low cost cement from some agricultural and industrial wastes. The utilization of these wastes would avail an economical and environmentally friendlier waste disposal methods and cheap cementing material. The cement made was based on the materials whose pozzolanic reaction was investigated. The materials tested for pozzolanicity included rice husks ash (RHA) from wastes of rice milling factories, spent bleaching earth (SBE) from oil processing factories and broken bricks (BB) from clay products manufacturers. Natural pozzolana (Ptuff) used for making East African Portland pozzolana cement was tested for comparative purposes. Heat content of rice husks (RH) and spent bleaching earth (SBE) was found to be adequate for activation of silica and alumina in the pozzolanic materials. Only a little kerosene was necessary for ignition. Acetylene lime sludge (ALS) from acetylene manufacturing industry and commercial hydrated lime (CHL) were used for the pozzolana-hydrated lime reaction. Pozzolanic activity of the materials with commercial hydrated lime (CHL) in different ratios was investigated on the pozzolanic materials separately. A blended calcined mix and a calcined blended raw mix of the materials was similarly tested. The results showed that the test materials were active pozzolanas. AI: 2 ratio of the pozzolanic material: CHL gave the best results. The 1: 2 ratio now using ALS was also investigated on the materials. ALS showed a superior performance than CHL with all the pozzolanic materials under test. Calcined blended raw mix exhibited a better performance than the blended calcined mix. The test materials were then singly interground in different proportions with laboratory made ordinary Portland cement (OPC) as per the Kenya Standard (KS) 02 1263 of 1993 [1] for cement tests. The resulting mixtures were then assessed using the same standard. The results showed that up to 25 percent replacement of the cement with the pozzolanic materials under test met the standard requirements. Calcined blended raw mix was interground with ALS and OPC from Bamburi Cement Factory in different percentages. The resulting products were subjected to the Kenya Standard [1]. Up to 45 percent replacement of the OPC with the material under test met the standard requirements, while higher percent replacements failed. A rough financial estimate suggested a running cost saving of up to 20 percent per tonne of PPC
The Effects of Herbivory on interactions of pollinators and flowers in Acacia SPP. (Fabaceae,mimosoideae) in Laikipia
(Kenyatta University, 2005) Otieno, Mark
Acacia trees are among the most dominant tree species found in semi arid ecosystems with a vast geographical distribution throughout the savanna habitats. The trees are leguminous and have remarkable ability to fix nitrogen in the soil, thereby, improving fertility. About all parts of an Acacia tree are edible to different types of animals and their leaves provide the only greenery in the dry season, so are bound to be eaten. As such, they support enormous pyramids of biomass in complex food chains with super predators at the apex. Economically, they are used as basic sources of fruits, firewood, medicine and secondary products for daily human livelihoods. Owing to their important, a lot of studies have focused on their growth ecology. Herbivory and reproduction are among the most studied aspects of Acacia. However, the interactive link between these two aspects and their effect on the growth success of Acacias is poorly understood. Understanding the link between herbivory and pollination, would not only provide useful information on the interaction of plants and diversity of visitors but also information on the floral morphometry and rewards to pollinators. The general objective of this study was to determine the effects of herbivory on interactions between pollinators and flowers in Acacia spp. The study was conducted at the Mpala Research Centre in Laikipia District of Kenya (0017'N, 36053'E) on one herbivore excluded plot (70m x 50m) and in the open grazed areas adjacent to the excusion plot. Acacia trees for investigation were randomly selected. Data were recorded on floral morphometric measurements and dehiscence in different browsing levels and simulated herbivory plots. The number and type of visitors to the flowers was also recorded besides determining the species diversity of wild flora within the study site. ANOVA was used to analyze variation in different flower attributes, SNKwas used to separate means with significant differences. Generally, unbrowsed trees produed significantly (P<0.05) more flowers, florets, anthers and larger floral diameters than naturally and heavilly browsed Acacia trees. Similarly, unbrowsed trees attracted more pollinators especially bees than naturally browsed trees. An earlier pollinator peak activity was recorded on unbrowsed trees than browsed trees. A significant shist of inflorescence dehiscence time occurred between unbrowsed and naturally browsed trees of A. nilotica, (KS=0.34, P<0.01), A. brevispica (KS=0.34, P<0.01) across the day. The unbrowsed trees attracted significantly more pollinators than naturally browsed trees probably because the unbrowsed trees had larger flowers thereby becoming more visible to pollinators from a distance than those of browsed trees. The delayed floral dehiscence of naturally browsed trees could have been caused by modification of the microclimate around the flowers making them open later in the day than unbrowsed trees. This study has shown than A. nilotica and A. brevispica vary their floral resources greatly when browsed, whereas A. etbaica tends to show compensatory floral growth. More studies therefore, need to be done on their reproductive success.
Effects of Tillage Method and Sowing Time on Growth, Water Use and Yield of Chickpea (Cicer arietinum L.) in Kenyan Dry
(Egerton University, 2007) Onyari, Charles N.
The need to provide sufficient protein food for an increasing population that is mainly resource poor requires opening up of marginal land for growing appropriate pulsessuch as chickpea. An experiment was carried out at KARI-Naivasha situated at an altitude of 1900 m, characterized with clayey to sandy loam soils in a split plot of randomized complete block design over two seasons (December 29, 2004 to May 26, 2005 and June 21 to November 15, 2007). The objective was to investigate the production of kabuli chickpea in Kenya as affected by tillage methods (main plots) and sowing times (subplots) and the effects of these factors on water use and yield ofthe crop. The overall mean height ranged from 39.7 to 47.7 cm under tillage methods with strip tillage resulting in relatively taller plants than the other tillage methods. Sowing times gave plant heights of 41.5 – 46.4 cm with early sown crops being relatively taller than late sown crop in both seasons. The leaf area index ranged from 2.50 to 3.31 and 4.22 to 5.44 under tillage methods in Season I and II, respectively. The corresponding valuesof LAI in the respective two seasons under sowing times were 2.80 to 3.20 and 3.59 to 5.69. Thecrop took 32.5 to 35.5 days to first flower and 61.8 to 61.4 days to 50% flowering in Season I and II, respectively. The mean time to physiological maturity was 120 days showed significant differences among tillage methods in both seasons. The time to first flower and 50% flowering however had non-significant differences (P<0.05) under both tillage method and sowing time treatments. The aboveground biomass yield of the chickpea varied from 3242.1 to 4231.3 kg ha -1 in Season I and 3035.8 to 4556.1 kg ha -1 in Season II under varying tillage treatments. The sowing time effects on biomass yield showed significant differences in biomass yields ranging between 3784.3 to 4095.0 kg ha -1 and 2938.1 to 4263.2 kg ha -1 in Season I and II, respectively. The grain yields obtained were significantly different (P<0.05) ranging from 1430.6 to 2544.9 kg ha -1 under tillage method effects and 1573.8 to 2235.3 kg ha -1 under sowing time treatment effects in both seasons. Tillage and sowing time effects on grain yield of chickpea were significantly different (P<0.05) only in the second season. In Season I, rains received in the post anthesis period of the chickpea thus causing it to exhibit indeterminate growth habit which resulted in additional yield increments of between 26.2 to 29.8% and 23.3 to 35.0% under various tillage and sowing time treatments, respectively. This gave a final overall mean grain yield of 2058.4 ka ha -1 . The 100-grain weight of the chickpea varied between 36.7 to 40.2 g in both seasons and showed non-significant differences under both factors of study. Infiltration rates were not significant under tillage and sowing times but affected the storage capacity ranging between 450.3 mm for first sowing time in Season II to 488.1 mm for conventional tillage in Season I. The mean seasonal evapotranspiration varied between 300.1 mm to 326.1 mm and showed interaction effects between tillage and sowing times in Season II. The mean biomass based water use efficiency (WUE b) and grain based water use efficiency (WUE g) ranged from 12.09 to 12.21 kg ha-mm -1 and 4.93 to 6.31 kg ha-mm -1 in Season I and II, respectively. The moisture use rate was non-significant with ranges of 2.23 to 2.58 and 2.18 to 2.56 mm/day in Seasons I and II, respectively.
Review of Methods of Estimating Parameters In Nonlinear Mixed-Effects (Nlme) Models
(University of Nairobi, 2007-07) Mbunzi, Stephen M.
This study is a critical review of theoreticalissues that underline the linear mixed effects (LME) and nonlinear mixed effects (NLME) models. These two areas are revisited under maximum likelihood and restricted maximumlikelihood estimation frameworks. We also review methods of estimating parameters in both linear and nonlinear mixed effects models. In the case of LME, we consider different ways of developing the likelihood estimators, key among these methods are the “pseudo-data” approach, orthogonal triangular decomposition method and the use of penalized least squares problem. For NLME, we intended to investigate the computational efficiency and accuracy of computational methods, like the b-splines, that could be used to approximate the log-likelihood function in non-linear mixed effects models. This was not achieved in this study but can be an interesting area for further research work. We critically review the four methods of estimating parameters by Pinheiro and Bates (1995) through proving a number of lemmas. Our proves led us to same stated results by different researchers in different papers. This is a key issue in the investigation of other expansion methods and comparing their computational efficiency and accuracy with these existing ones. We conclude by giving an insight into linear mixed effects models by analyzing a data set from livestock where we examine incorporation of random effects to study variations among rams (sires) and ewes (dams) and their influences on lamb weaning weight. Factors like year of birth of the lamb, sex of lamb, age at weaning, age of dam, ewe breed and ram breed are found to influence the weaning weight differently. With the random terms (ewes and rams) specified in the model the estimate of the residual among lamb variance is found to reduce due to taking into account the variations among rams and ewes within breeds. It was our intention to obtain heritability estimates which determine the proportion of the variation among offspring that have been handed down from parents out of these random estimates.
Contribution of Dynamic Instability to Microtubule Organization
(University of Manitoba, 2008) Karuku, Simon
Microtubules are hollow cylindrical protein structures found in all eukaryotic cells, and essential in several cellular processes, including cell motility, cell division, vesicle trafficking and maintenance of cell shape. The building block of microtubtles, tubulin, is one of the proven targets for anticancer drugs. A microtubule exhibits a remarkable property, termed dynam,i.c i,nstabi,Ii.ty, in which it is able to switch stochastically between two distinct states. In one state, the microtubule grows while in the other, it shrinks. The balance between the growing and shrinking states is crucial for the normal functioning of the cell. One of the interesting questions that cell biologists have pondered over the years is: what is the biological function of dynamic instability? While some great strides have been made in answering this question, the details of the precise nature of the mechanism of dynamic instability in relation to their roles are not well understood. In this thesis some biologically pìausible mathematical modeìs for microtubule dynamics 'in ui,tro are developed. Two of the models are developed with the exclusion of dynamic insiability while the others are with its inclusion. Aiso considered are two different modes of nucleation of microtubules: saturating and non-saturating mode. The models are analyzed and numerical simulations conducted, with an aim of mathematically assessing the role of dynamic instability in the integral microtubule dynamics i,n ui,tro. Results indicate that dynamic instability induces the formation of microtubules from the tubuÌin subunits, and that dynamic instability depends on the GTP-tubulin concentration
Effects of Tillage Method and Sowing Time on Growth, Water Use and Yield of Chickpea (Cicer arietinum L.) in Kenyan Dry Highlands
(2010) Onyari, Charles N.
The need to provide sufficient protein food for an increasing population that is mainly resource poor requires opening up of marginal land for growing appropriate pulses such as chickpea. An experiment was carried out at KARI-Naivasha situated at an altitude of 1900 m, characterized with clayey to sandy loam soils in a split plot of randomized complete block design over two seasons (December 29, 2004 to May 26, 2005 and June 21 to November 15, 2007). The objective was to investigate the production of kabuli chickpea in Kenya as affected by tillage methods (main plots) and sowing times (subplots) and the effects of these factors on water use and yield of the crop. The overall mean height ranged from 39.7 to 47.7 cm under tillage methods with strip tillage resulting in relatively taller plants than the other tillage methods. Sowing times gave plant heights of 41.5 – 46.4 cm with early sown crops being relatively taller than late sown crop in both seasons. The leaf area index ranged from 2.50 to 3.31 and 4.22 to 5.44 under tillage methods in Season I and II, respectively. The corresponding values of LAI in the respective two seasons under sowing times were 2.80 to 3.20 and 3.59 to 5.69. The crop took 32.5 to 35.5 days to first flower and 61.8 to 61.4 days to 50% flowering in Season I and II, respectively. The mean time to physiological maturity was 120 days showed significant differences among tillage methods in both seasons. The time to first flower and 50% flowering however had non-significant differences (P<0.05) under both tillage method and sowing time treatments. The aboveground biomass yield of the chickpea varied from 3242.1 to 4231.3 kg ha-1 in Season I and 3035.8 to 4556.1 kg ha-1 in Season II under varying tillage treatments. The sowing time effects on biomass yield showed significant differences in biomass yields ranging between 3784.3 to 4095.0 kg ha-1 and 2938.1 to 4263.2 kg ha-1 in Season I and II, respectively. The grain yields obtained were significantly different (P<0.05) ranging from 1430.6 to 2544.9 kg ha-1 under tillage method effects and 1573.8 to 2235.3 kg ha-1 under sowing time treatment effects in both seasons. Tillage and sowing time effects on grain yield of chickpea were significantly different (P<0.05) only in the second season. In Season I, rains received in the post anthesis period of the chickpea thus causing it to exhibit indeterminate growth habit which resulted in additional yield increments of between 26.2 to 29.8% and 23.3 to 35.0% under various tillage and sowing time treatments, respectively. This gave a final overall mean grain yield of 2058.4 ka ha-1. The 100-grain weight of the chickpea varied between 36.7 to 40.2 g in both seasons and showed non-significant differences under both factors of study. Infiltration rates were not significant under tillage and sowing times but affected the storage capacity ranging between 450.3 mm for first sowing time in Season II to 488.1 mm for conventional tillage in Season I. The mean seasonal evapotranspiration varied between 300.1 mm to 326.1 mm and showed interaction effects between tillage and sowing times in Season II. The mean biomass based water use efficiency (WUEb) and grain based water use efficiency (WUEg) ranged from 12.09 to 12.21 kg ha-mm-1 and 4.93 to 6.31 kg ha-mm-1 in Season I and II, respectively. The moisture use rate was non-significant with ranges of 2.23 to 2.58 and 2.18 to 2.56 mm/day in Seasons I and II, respectively.
Socio-economic determinants of low birth weight in Kenya: Logistic regression analysis
(University of Nairobi, 2010) Atitwa, Edwin
Babies born with Low-birth weight are at increased risk for serious health problems which are accompanied by disabilities and even death. Hence this study aims to determine socioeconomic factors that lead to low birth weight of children in Kenya. Data used was from Kdhs 2003 and the significant effect of socio-economic determinants on low birth weight was examined using logistic regression analysis data is categorical and continuous in nature, where predictor variables being socio-economic determinants and birth weight being dependent variable. Results indicate that out of ten socio-economic factors involved in the study, six revealed some significant effects on the children with low birth weight, four determinants namely , sex of the child, antenatal visit for pregnancy, antenatal care attendance and time wanted pregnancy has no significant impact to the infant birth weight holding other factors constant. The six major socio-economic determinants which can alter the weight at birth for babies born in Kenya were Religion, Educational attainment, Age of household head, Smokes nothing, Current marital status, and Size of child at birth. Therefore Socio-economic determinants have a significant effect on Low birth weight which suggests a strong negative associated with infant survival in Kenya independent of other risk factors. Children can be ensured a healthy start in life if women start pregnancy healthy and well nourished, and go through pregnancy and childbirth safely. Also expectant mothers should keenly focus on the socio-economic determinants by avoiding some like smoking, acquire education so that they can understand how to take care of themselves and not always to depend on the doctor's advice, give enough time and prepare for the pregnancy
Spatial Analysis and Mapping of Infant Mortality in Kenya On The Basis Of Demographic and Health Survey Data
(University of Nairobi, 2010) Mutwiri, Robert M.
This study set out to examine and map the spatial variation of infant mortality in Kenya. We used data from Demographic and Health Survey (DHS) database to explore spatial variation. Generalized linear mixed inodel(GLMM) with Enumeration Areas (EA) specific random effects was used to assess the effects of geographical heterogeneity and other covariates. The model based Geostatistical methods were used to quantify the spatial variations of the observations using the variograms and fitted the exponential and matern parametric models to the sample variograms. Then utilizing the fitted variogram function, Trans-gaussian kriging was performed infant mortality rates based on both models and produced smooth maps. Generalized linear mixed model (GLMM) showed significant geographical heterogeneity in infant mortality. However, moran's I statistic showed spatial autocorrelation unaccounted for by GLMM. Modeling the correlation between people as a decreasing function of the spatial distance between them, Geostatistical models gave information no only on the magnitude but also on the scale of spatial variation. The socioeconomic status and infant mortality varied significantly across districts in Kenya. EA indicators better explained spatial variation of mortality when measured across a continuous space rather than within administrative areas. The resulting map broadly agreed with the the previous studies on the variation of risk in the country, and further showed marked variation even at local level. High risk areas were in Nyanza regions, while low risk areas are in Central of the country. The maps provided an initial description of the geographic variation of IMR in Kenya, and might help in the choice and design of interventions, which is crucial for reducing the child mortality by two thirds by 2015.
Connecting People using Latent Semantic Analysis for Knowledge Sharing
(2010-01) Mugo, David M.
A shift from technology-oriented knowledge management to people-oriented knowledge management is indispensable. To achieve this, organizations must understand the nature of knowledge. In this work, knowledge has been found to be both a process and a collection of artifacts. This makes knowledge and the knower to be two inseparable entities. Consequently, the appropriate way to share both the explicit and the implicit knowledge components is through people-with-people connection. However, from existing barriers like location and time differences among others, people-with-documents connection is proposed as an intermediate step. The investigation of latent semantic analysis (LSA) in achieving people-with-documents connection has revealed decreased precision performance at higher recall performance. A solution to include annotations in the technique has been proposed to refine knowledge representation into the LSA technique. Annotation process based on domain ontologies has been proposed to compliment the LSA knowledge mining process from documents with domain knowledge represented by ontologies
The Effects of Market Reforms on Irish Potato Price Volatility in Nyandarua District, Kenya
(University of Nairobi, 2010-08) Mwangi, Samuel C.
In the early 1990’s, the Kenyan government implemented refor ms in the agricultural sector that affected the volatility of agricultural product prices. However, there is lack of empirical evidence on the effects of these reforms on the level and volatility of Irish potato prices. This study evaluates the effects of market reform policies involving the decontrol of input and output prices on the evolution and volatility of Irish potato prices in Nyandarua district. The purpose of this study is to examine the effect of market reforms on Irish potato price variability. By using an Autoregressive Conditional Heteroscedasticity in Mean model, a monthly time series data set for the period 1986-2005 was utilized to identify the effects of the market reforms on the volatility of Irish potato prices. Results indicate that the implementation of market reform policies led to higher prices and reduction of price volatility. An increase in price level coupled with a decrease in price volatility after the implementation of market reform policies implies that with the reforms the Irish potato producers were better off than without the reforms. The high prices and low price volatility served as an incentive for the Irish potato farmers to boost production during the post reforms period. The study recommends development of storage and communication infrastructure, use of commodity exchange markets, improvement in productivity, and provision of an efficient market information system as necessary measures to enable the farmers to realize maximum benefits from the effects of the implementation of market reform policies.
Strategic Alliances between Jomo Kenyatta University of Agriculture and Technology (JKUAT) and Middle Level Colleges in Kenya
(University of Nairobi, 2010-11) Kinyua, Jesse M.
Strategic alliance is one of many methods of strategy development. It has been defined as a situation where two or more organizations share resources and activities to pursue a strategy. Alliances vary considerably in their complexity, from a simple two partner alliance co-producing a product to a one with multiple partners providing complex products, services and solution. Research on strategic collaboration between firms has received increasing attention in literature during the last decade, reflecting the increasing frequency and importance of strategic alliance in business. In the recent past, competitive firms are truly smart at conducting their business and have learnt important lessons in the process. You need to know when and how to compete, but even more importantly you need to know when and how to co-operate. Many firms these days have come to rely on alliances as strategic necessities for sustaining competitive advantage and creating customer value. In the recent past, higher education sector in Kenya has experienced dynamic changes in the external environment. Increasing demand for higher education as population grows has stretched physical infrastructure of public universities. Government funding has also been dwindling and not going in tandem with increasing demand. Competition has gone a notch higher as private and international universities fight to increase their market share. All these have prompted public universities managers to be proactive and think “outside the box”. We are currently seeing public and even private universities collaborating with middle level colleges in same domestic market. The purpose of this study was to shed some light on motivation of such domestic strategic alliances where internationalization is not one of such motive. The research study through a case study of JKUAT also sought to know the challenges encountered in the formation of the network. The research methodology used was a case study. The study sought to have a thorough understanding of the phenomenon from the perspective of JKUAT. An in-depth case study was used. Data was gathered through interviews with three respondents who were involved in the formation and management of the alliances. Content analysis was used to analyse the information gathered. The study qualified the relationship between JKUAT and collaborating middle level academic institutions to be a network. The alliance were formed with a motive/s of enabling students who would otherwise be locked out of universities owing to stiff competition to progress with their studies hence exploiting this niche market. It also intended to reduce brain drain and capital leaving Kenya economy. The collaborations intended also to tap the resources from vocational economies of scale and enjoy faster payback on investment. The network faced challenges like opportunism by some partners, lack of adequate man power, loss of trust among partners, difficulties in meeting critical deadlines by partners, failure to discover shortcomings before “marriage” and hence being stuck with the wrong partners and lack of experience in the management of strategic alliance by some partners. However, these challenges were amicably sorted out or, they learnt to live with them and relationships continued to thrive. The alliance success was found to be more than luck and was based on successful effort despite natural occurrence of tensions with a failure rate of 24.3% when the dormant (inactive) relationships were included to those that pulled out. The study recommended that the commission of higher education should undertake rigorous inspections to public, private universities and middle level colleges entering into collaboration arrangements. The brand owners should ensure that the middle level colleges have enough qualified personnel and proper infrastructure to ensure quality. The challenge of high demand for education can also be solved by using ICT for online education which should focus from teaching to learning by creating new learning environments. Due diligence is necessary in the formulation stage by ensuring that prospective partners have the right attitude toward quality and the brand owner should be able to confirm this. Trust should start to be cultivated at this stage by all partners and retained in the long run. The study had some limitations. It would have been for instance been interesting to get the views of all network members. However this was not possible, the thirty alliance members are scattered all over the country. Time was a limiting factor as research was to be done within its planned time frame. The research would have wished to interview more respondents to follow up on some information gathered. Some of those targeted respondents happened to be unavailable. The researcher would have wished to carry out a survey from JKUAT and thirty (30) collaborating institution. However, this was not possible and the researcher got the view from the perspective of JKUAT. This should be an area for further study. Other public universities like Kenyatta and Moi University are collaborating with tertiary college albeit on a small scale. A survey study can be employed by other scholars to include them in their study.
Factors Affecting the Implementation of Water Sector Reforms Strategy: A Case of Tana Water Services Board
(Kenyatta University, 2011) Chege, Purity Nyambura
According to the National Water Services Strategy (2007-2015), water is the most important natural resource, indispensable for life and the backbone of the growth and prosperity of mankind. Due to poor access of water and sanitation the Government initiated a process of reforms for the entire water sector which led to a new water policy and new sector strategies with an aim of attaining some outcomes like increased access to water and sanitation, increased funding among others. The Water Service Boards have however not been able to sufficiently implement the water sector reform strategy as expected since most of the expected outcomes of the water reforms have not been attained. It is in the light of this that the researcher wanted to find out why the expected outcomes had not yet been attained by conducting a study on the factors affecting the implementation of the water sector reforms strategy at Tana Water Services Board. To conduct the study, descriptive survey method was used. The study was carried at Tana Water Services Board Headquarters in Nyeri where a total population 75 staff members were targeted. Primary data was collected by use of questionnaires while secondary was through periodic reports , journals, government publications, academic works, internet and TWSB’s financial records . Data analysis was done by descriptive statistics. The collected data was analyzed by use of descriptive statistical techniques and presented through frequency tables, of pie charts, bar charts. The study established that 87.8% of the respondents felt that autocratic leadership style affected implementation of the strategy. 51.22% of the respondents indicated that planned activities were not adequately funded thus affecting implementation of strategy. Majority of the respondents ( 90.2 % ) were aware of the Board’s core values but some felt that the same were not upheld thus adversely affecting implementation of water sector reforms strategy. The study showed that existing systems required improvement while new ones introduced to effectively implement water sector reforms strategy. Based on the findings, the study proposes some recommendations that are; The Board to embrace participatory leadership style, to explore other avenues of obtaining resources other than relying on budgetary allocations from the government, uphold Board’s core values, ensure staff are well versed with all policies and strategies and improve existing systems, innovate and adopt new ones.
Preparation and Properties of Long Afterglow CaAl2O4 Phosphors Activated by Rare Earth Metal Ions
(University of the Free State Republic of South Africa, 2011-11) Wako, Ali Halake
This work comprises of several aspects of calcium-aluminate phosphor activated with rare earth metal ions i.e. (CaAl2O4:Eu2+, Nd3+, and Dy3+). In particular the luminescent and structural properties of the long afterglow CaAl2O4:Eu2+,Nd3+,Dy3+ phosphors prepared by urea-nitrate solution-combustion method were investigated. The solution-combustion method is more efficient because phosphors with high efficiency were obtained at low temperature (500 oC) in a very short period of time (5 min). The effects of varying concentration of host matrix composition (Ca:Al), flux i.e. boric acid (H3BO3), activator (Eu2+) and co-activator (Nd3+/Dy3+) mass ratios and urea ((NH2)2CO) on the structural, luminescent, and thermoluminescent(TL) properties of the CaAl2O4:Eu2+, Nd3+, Dy3+ phosphors were studied. It was observed that Ca:Al mass ratios greatly affect the crystalline structure of the material. The results of the X-ray diffraction (XRD) analysis reveal that the formation of several crystalline phases depends on the ratios of the host material. The XRD peaks show the presence of other phases such as Ca3Al2O6 and CaAl4O7 but the predominant phase formed was that of CaAl2O4. However it was found that the crystalline structure is generally not affected by the variation of the co-dopants concentration. Photoluminescence (PL) studies revealed a general rise in intensity with an increase in the mass ratio of Ca:Al. The highest PL intensity was observed with 0.7% Ca. The luminescent intensities vary from each other when co-doped with various proportions of Nd3+ and Dy3+. The addition of H3BO3 favored the formation of pure monoclinic CaAl2O4 phase while the variation of the amount of ((NH2)2CO) showed mixed phases although still predominantly monoclinic. Both boric acid and urea to some extent influence the luminescence intensity of the obtained phosphor but unlike the case of CO(NH2), the emission peak for H3BO3, does not shift evidently because the energy level difference of 4f-5d does not change obviously. The broad blue emissions consisting mainly of symmetrical bands having maxima between 440–445 nm originate from the energy transitions between the ground state (4f7) and the excited state (4f65d1) of Eu2+ ions while the narrow emissions in the red region 600-630 nm arise from the f-f transitions of the remnant unreduced Eu3+ions. High concentrations of H3BO3 generally reduce both intensity and lifetime of the phosphor powders. The optimized content of H3BO3 is 5.8 mol % for the obtained phosphor with excellent properties. XRD analysis of the influence of Eu2+ and Nd3+ doping concentrations on the morphological, structural and PL properties of the CaAl2O4: Eu2+; Nd3+ phosphor, depict a dominant monoclinic phase that indicates no change in the crystalline structure of the phosphor even with high concentration of Eu2+ or Nd3+. The Energy Dispersive x-ray Spectroscopy (EDS) and Fourier Transform Infra-Red Spectroscopy (FTIR) spectra showed the expected chemical components of the phosphor. The excitation iv spectra show one broadband from 200 nm to 300 nm centered around 240 nm corresponding to the crystal field splitting of the Eu2+ d-orbital. The prepared phosphor compositions exhibit PL emission in the blue region with a maximum around 440 nm. This is a strong indication that there was dominantly one luminescence centre, Eu2+ which represents emission from transitions between 4f7 (8S7/2) ground state and the 4f6-5d1 excited state configuration. Two other, minor peaks, at 580 and 614 nm indicate the presence of remnants of Eu3+ ions as a result of incomplete reduction during sample preparation. High concentrations of Eu2+ and Nd3+ generally reduce both intensity and lifetime of the phosphor powders. The optimized content of Eu2+ is 0.36 mol % and for Nd3+ is 0.09 mol % for the obtained phosphors with good properties. The decay characteristics exhibit a significant rise in initial intensity with increasing Eu2+ doping concentration while the decay time increased with Nd3+ co-doping. Analysis of the TL glow curves is one of the most significant ways to measure the number of traps and also the activation energy of the trap levels in luminescent materials. In the present study TL properties of the CaAl2O4:Eu2+, Nd3+,Dy3+ phosphors were investigated above room temperature by use of Nucleonix 1009I TL reader. The trap depths were estimated with the aid of the peak shape method. The glow curve of CaAl2O4:Eu2+ with a first peak at 50 °C was found to correspond to several traps. The ratio of Nd3+:Dy3+ ions were observed to influence the position, concentration and type of traps formed. The observed afterglow can be ascribed to the generation of suitable traps due to the presence of the Nd3+ trap levels. Trivalent rare earth ions (Nd3+/Dy3+) are thought to play the role of hole traps in calcium aluminate phosphors (CaAl2O4:Eu2+). In these phosphors, Eu2+ ions act as luminescent centre emitting in the blue (λ max = 440 nm) region. Despite a large number of research on the phenomenon the mechanism of the persistent luminescence of CaAl2O4:Eu2+,Nd3+,Dy3+ has not been well presented. A proper understanding of the exact luminescence mechanisms and the identification of trap levels or locations in long phosphorescent materials is required for their use in areas such as detection of radiation, sensors for cracks in buildings, fracture of materials and temperature among others.
Ethical Dilemmas Experienced by Nurses in the Critical Care Units in Kenyatta National Hospital
(University of Nairobi, 2012-07) Mutinda, Jostine
Introduction- Ethical issues have emerged in the recent years as a major component of health care for the critically ill patients, who are vulnerable and totally depend on the caregiver, optimally the nurse working in the critical care unit. As a result nurses working in the Critical Care Units are faced with ethical dilemmas on a day to day basis in the course of executing their duties. Ethical dilemmas have therefore become one of the priority concerns in the nursing profession that require urgent attention in Kenya. As the provision of care to the critically ill becomes more complex due to technological advancement, and the profession of nursing more autonomous, professional accountability cannot be overemphasized. (Fry, 2002). The complex nature of the health problems faced by patients admitted in ICU coupled with extensive use of very sophisticated technology requires at times rapid decision making. Ethical dilemmas confront even the most experienced nurse (Breen C.M. et al, 2004). Those working in KNH ICU are not any different particularly considering particularly considering that KNH is public hospital having the biggest ICU in the country. Additionally it admits patients from various walks of life and the nurses have diverse socio- demographic factors. However their perception and magnitude of ethical dilemmas they face while working in these areas and how they resolve them have not been studied. Duration of the study: The study took five weeks. Pretesting of the questionnaires took two days. Objective: To explore ethical dilemmas experienced by nurses working in the critical care areas at Kenyatta National Hospital and factors influencing the nurses‟ ethical decision making. Study question: What ethical dilemmas face nurses working in the critical care areas at KNH and how do they resolve them? Materials and methods: An exploratory survey study design was adopted whereby 123 nurses shall be requested to participate in the study upon signing an informed consent. These participants were employees of KNH working in the critical care areas during the time of data collection. The study was conducted in the critical care units of KNH. Permission to conduct the study was sought from the KNH management. Clearance to conduct the study was sought from University of Nairobi and KNH ethical research committee. Sampling was done using simple random sampling method whereby 123 nurses were picked from the total of 184 nurses. Out of these 3 did not return the questionnaires. Questionnaires were distributed to the participants to give the information needed. Data management: Upon completion, data was cleaned and analyzed using SPSS. Chi square test was used to assess the relationship between variables. Finally, propositions and conclusions were made based on apparent patterns or relationships within the data. Results: This study on has sought to ascertain what nurses experience as ethical dilemmas while working in the critical care areas and how they have dealt with these issues. The dilemmas which were of major concern to nurses included: prolonging the dying process, withdrawing/ withholding treatment, resuscitation (DNR) orders (table 8), unsafe nurse- patient ratios and allocation of scarce medical resource, rights of pediatric patients, and nursing of critically ill patients who may pose a risk to the nurses. In dealing with the issues majority of the nurses of the respondents indicated that they would consult with the physicians. Others reported to the nurse team leaders while a few made decisions without consulting a third party. Some socio- demographic factors were shown to influence the experience of ethical dilemmas by the respondents. These included: the age, level of knowledge on ethical issues, professional qualification and availability of work place resources. It was noted those aged below 35 years experienced more dilemmas than others while those whose level of knowledge was low experienced less dilemmas probably due to their inability to identify the dilemmas as accurately as those more knowledgeable. Those who reported to have adequate work place resources experienced fewer dilemmas. They probably knew the channels to follow to resolve issues compared to their colleagues who reported inadequate resources. Conclusion and recommendations- this study shows that ethical dilemmas are an issue of concern among the nurses working in the critical care units of the KNH. The experience of ethical dilemmas is influenced by various socio- demographic factors. In resolving the dilemmas most nurses would consult the Doctors showing that probably the profession is still at the place of subordination to the medical profession. It is notable that some nurses chose to make decisions without consulting. They may probably be confident of their ability to solve problems without involving a third party. Results of the study will be used to make recommendations for shaping of the curriculum for training of critical care nurses to include ethical decision making process as this need for education on ethical issues has been identified as shown in the results. The findings can be utilized as literature for further research on ethical issues.
Cytokine Levels and T cell Apoptosis Associated With Cerebral Malaria Immunopathology During Plasmodium berghei Anka Infection In A Mouse Model
(2013) Mugweru, Julius
During the course of malaria infection, a range of pro- and anti-inflammatory cytokines are produced by the host immune system. Successful recovery from malaria involves striking a balance between these counteracting cytokines. The cytokine imbalance contributes to pathological features but their exact levels have not been elucidated. The present study aimed at investigating the role played by circulating cytokines in pathophysiology of cerebral malaria. Using an experimental cerebral malaria (ECM) model, the profile of five serum cytokines was determined by employing Cytometric Bead Assay. Seventy-two BALB/c mice (7-9 week/old) were intraperitoneally inoculated with approximately 1 x 105 parasitisized red blood cells at day 0 and randomized into six groups (six mice/group). Another set of noninfected mice was included to serve as control. The mice were sacrificed at day 4, 6, 8, 11 and 20 pi. The possible role of cytokines in inducing T-cell apoptosis associated with CM was investigated using the whole genomic DNA extracted from splenic and brain lymphocytes. Significantly higher systemic levels (P<0.05,) of IFN-γ (mean ±S.D 210.6±133, 169.8±80.5, 203.6±91.6, 22.0±3.5 pg/ml), were observed between day 8 and 20 p.i while TNF-α levels were significant at days 4, 8 11, 14 and 20 respectively (M ±S.D 2.9 ± 0.2, 33.9±17.5, 95.5 ±17.0, 22.1±3.6 pg/ml) in BALB/c mice that survived until day 20 pi with a higher parasitemia (up to 52.6%±0.8). Significant concentrations (P< 0.05), of IL-4 (M ±S.D 14.6±2.5, 10.6±1.9, 9.6±1.3 pg/ml) were observed between day 4 and 8 respectively but afterwards its levels remained low throughout the course of infection. IL-5 levels (M xix ±S.D 4.1±0.7, 3.4±1.6) had significant differences at day 11 and 20 pi. The study found IL-4 to be elevated between days 11 and 20 respectively with no significant differences (P>0.05) being reported. T-cell pathology was revealed by fragmentation of whole genomic DNA during the infection which coincided with elevated systemic pro-inflammatory (IFN-γ and TNF-α at day six) responses which further accelerated the severity of CM. The study demonstrated a parallel link between T-cell pathology and elevated levels of Th1 cytokines concentrations in the brain and the spleen. This study revealed that elevated levels of proinflammatory cytokines induce inflammation and cellular apoptosis inhibiting parasite clearance. Thus, interventions to regulate the Th1 cytokine responses may be beneficial in the prevention of severe CM. Further work is needed on IL-2 IL-10 and IL-12 cytokines that could be involved in the pathology
Instructional Roles in Diploma Nursing Education in Meru: Adaptation, Self Sufficiency and Sustainability
(Kenya Methodist University, 2013) Gitonga, Pius
Nursing education forms the basis of professional existence, development and sustainable future. The purpose of this study was to establish how nurse educators adapted to increased instructional workload, how they were self-sufficient in performing, and how they would sustain instructional roles in diploma nursing training in colleges within Meru. The target population was fifty two nurse educators who were all invited to participate. Forty six nurse educators participated in the study by availability, willingness to participate and giving a signed consent. A descriptive cross-sectional study design was carried out using a self-administered questionnaire for data collection after a pilot study showed validity and reliability of the tool. Data was collected after consent appointments with the principals and respondents of the participating colleges and was analysed using descriptive statistics performed at 95% confidence interval. The findings are presented in tables, bar graphs, pie charts and a discussion. The study found out that nurse educator to student nurse ratio was 1:20 which indicated instructional role overload. It was evident that there was role overload, teamwork challenges, lack of a mentoring program for novice faculty, and limited role orientation before role assignment. Educators had adequate adaptation mechanisms in planning, adjustment of instructional plans and taking in arising additional instructional roles. Adequate commitment to instructional roles and long service in the same diploma nursing training institution were indicators of selfsufficiency. Adequate adaptation mechanisms and self-sufficiency were indicators of sustainable instructional role performance. The recommendations made were; diploma nursing training institutions to recruit more nurse educators, ensure an orientation program for inducing novice faculty to institutional culture of performing the instructional roles, encourage and ensure planning and execution of plans for instruction and solve instructional challenges as a team for continuity/sustainability of diploma nurse training and education.
Influence of Khat (Miraa) Production, Trade and Consumption On Primary School Dropout among the Boys in Kangeta Division, Igembe South District, Kenya
(Egerton University, 2013-02) Njeru, Lucy K.
Education for all is a global development need. Achievement of universal primary education is addressed by the second United Nations Millennium Development Goals (MDG). In a bid to achieve this goal, Kenya government initiated Free Primary Education (FPE) in January 2003. However, despite this effort, there has been educational wastage through declined enrolments and increased dropout rates, which are common phenomena in Kangeta Division, Igembe South District. The purpose of this study was to determine the influence of khat production, trade and consumption on primary school dropout among boys in the Division. The study focused on boys aged 6-16 years and was guided by 3 research questions. These were. does providing the required labour for khat production cause the primary school boys to drop out of school?; how does khat consumption by primary school boys influence boys’ school dropout?; to what extent does khat trade by primary school boys influence their school dropout?. The study adopted a cross-sectional survey design. A sample size of 210 dropouts was used based on Balians’ recommendation of having an average sample of 200 respondents adjusted by 10-15 % to cater for attrition. All the head teachers of the selected 10 schools were included in the sample to give a total of 220 respondents. Questionnaire and interview guide whose reliability coefficients were alpha 0.83 and 0.72 respectively were used for data collection. Validity of the instrument was ascertained by a panel of five experts from the department of Agricultural Education. Data was analyzed by a t-test and a chi-square test using the SPSS software package. Frequency tables and percentages summarized the results. The study findings indicated that the drop out of school among the primary school boys in the Division is as a result of providing cheap labour in miraa production. The findings revealed the effects of khat chewing to the behaviour of the user and it is this behaviour that causes the boys to drop out of school. The findings further indicated that the easy money these boys earn after engaging in khat business influence them to drop out of school. These findings of the study would be useful to the entire community, educationists and policy makers in finding ways of reducing the school dropout for the boys in Kangeta Division.
Structure and Biomass Accumulation of Natural Mangrove Forest at Gazi Bay, Kenya
(Kenyatta University, 2013-08) Githaiga, Michael N.
Mangroves occupy only 0.4% of forested areas globally but are among the most productive ecosystems on earth. They account for about 11% of the total input of terrestrial carbon into the oceans. The above ground carbon stock in mangroves in some parts of the World has been estimated to be as high as 8 kg C m -2 ; with a similar amount reported for below ground components. Although a lot of research has been done on estimates of mangrove biomass in Kenya, there is no information on biomass accumulation across the zones. The present study aimed at determining the forest structure and estimating above and below ground biomass accumulation in Gazi Bay mangrove forest. Forest structure was determined in the western, middle and eastern forest blocks of the Gazi Bay mangrove forest while biomass accumulation studies were done in the western forest block. In-growth cores of 80 cm long × 20 cm wide and 60 cm-depth were used to estimate below ground biomass accumulation. Data on tree height and stem diameter at breast height (DBH-130) were used to estimate above ground biomass accumulation. Shoots were tagged for monitoring leaf phenology. Periodic measurements of environmental variables across four mangrove species zones were done at the beginning, thereafter every four months for a year. Composition and distribution pattern of natural regeneration was obtained using the method of linear regeneration sampling (LRS). Among the soil environment properties investigated, salinity had a significant negative correlation with above ground biomass accumulation. Comparing the four forest zones, Sonneratia alba had the highest biomass accumulation rate of 10.5 ± 1.9 t ha-1 yr -1 . This was followed by Rhizophora mucronata (8.5 ± 0.8 t ha-1 yr -1 ), Avicennia marina (5.2 ± 1.8 t ha-1 yr -1 ), and Ceriops tagal (2.6 ± 1.5 t ha-1 yr -1 ). There were significant differences in above ground and below ground biomass accumulation across zones (F (3, 8) = 5.42, p = 0.025) and (F (3, 8) = 16.03, p = 0 001) respectively. Total biomass accumulation was significantly different across zones (F (3, 8) =15.56, p = 0.001). A root: shoot biomass accumulation ratio of 2:5 was computed for the whole forest. The finding of this study gives better estimates of mangrove carbon capture and storage which can be used in negotiations for carbon credits in the evolving carbon market.
Relationship between Selected Motivational Factors and the Performance of Public Secondary School Agriculture Teacher’s in Imenti South District, Kenya
(Egerton University, 2013-11) Kirimi, Florence K.
Teacher motivation is very important as it directly affects the students’ performance. The performance of agriculture teachers in Imenti South District has been low compared to other districts. This has been characterized by a decline in the agriculture subject results. This might have been contributed by inadequate teacher motivation. The purpose of this study was to determine the relationship between selected motivational factors and the performance of secondary school agriculture teachers in the district. The study used a cross-sectional research design. The target population comprised of all the head teachers and agriculture teachers of secondary schools in Imenti South District. Fifty-nine head teachers and fifty-nine agriculture teachers were randomly sampled from 70 schools in the District. A structured questionnaire was used by the researcher to collect data from the respondents. The reliability of the instrument was estimated using Cronbach’s Alpha Coefficient. Data was analyzed with the help of Statistical Packages for Social Sciences (SPSS). Descriptive statistics specifically frequencies and percentages, and inferential statistics particularly Pearson’s Product Moment Correlation were applied in data analysis. The hypotheses were tested at a 0.01 confidence level. The general working conditions in secondary schools were fair as noted by 69% of the respondents. The results also indicate that there is a positive correlation (0.444) between working condition and performance of agriculture teachers. The results also indicate that the teaching load of most teachers (59%) was moderate; however, they had been assigned other non-teaching roles. Further, the study revealed a negative correlation (-0.416) between teaching load and performance of agriculture. A correlation analysis between interpersonal relations and performance of agriculture teachers revealed a positive correlation of 0.403 and a pvalue of 0.01. The overall performance of agriculture teachers in the District has been fair for the last three years; however, this can be improved by reducing the teachers teaching load, improving the working conditions and interpersonal relations in the schools. The study recommends that agriculture teachers should make use of the surrounding community in the teaching of agriculture. Also, the school administrators should equip the available workshops with appropriate tools and equipment and in schools without workshops; the administrators should construct them and equip them appropriately to facilitate effective teaching.

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