Abstract In this thesis, I investigate the application of various statistical methods towards analysing GPS tracking data collected using GPS collars placed on large mammals in Kruger National Park, South Africa. Animal movement tracking is a rapidly advancing area of ecological research and large amount of data is being collected, with short sampling intervals between successive locations. A statistical challenge is to determine appropriate methods that capture most properties of the data is...
ABSTRACT Common bean is an important legume and a cheap source of proteins. Phaeoisariopsis griseola causing Angular Leaf Spot disease (ALS) is a major constraint for common bean production in Kenya contributing to yield losses estimated at 80%. ALS disease has been difficult to control using cultural practices and resistant varieties which necessitates the need to search for an alternative management option. Synthetic fungicides too have numerous side effects, so the plant-based products are...
ABSTRACT Lake Victoria is the largest freshwater and fishery lake in Africa. Kisumu City on the Winam Gulf has industrial activities that dispose of their effluents into the lake which may contaminate aquatic species thus threatening human health. It is not known fully if these anthropogenic activities adversely change the water quality and contribute heavy metal pollutants to the lake water and/or cause high accumulation of the metals in sediments and fish from the gulf. The study employed a...
ABSTRACT Acute Myelocytic Leukemia (AML) is a cancer of the bone marrow characterized by arrested maturation along with uncontrolled proliferation of hematopoietic progenitor cells. Mostly, it affects persons of age 65years and above. In AML, there is absence or low amounts of Estrogen Receptors in the bone marrow. Various studies have associated Estradiol to the variation of ER. However, the exact role Estradiol is still not known in association with the onset and progression of AML. The mai...
ABSTRACT Iron deficiency, mainly from iron deficient diets, impedes cognitive, psychomotor and physical development, especially of school age children. Flour fortification with iron, an effective intervention for increasing iron intake, is influenced by the amount of fortified food consumed. Intra-household food distribution (IHFD) patterns may influence how much food a child gets, hence amount of iron from fortified flour. However, information on such influence on iron intake of school age c...
ABSTRACT Finger millet (Eleusinecoracana (L.) Gaertn) is one of the most important crops among the small millets. In Kenya yields are generally low, because of blast caused by the fungus Pyricularia grisea. Low finger-millet production accelerates incidences of malnutrition. Management has been challenging with cultural approach showing minimal success. Comparatively the use of actinomycetes species as a bio-control agent in management of rice blast caused by a similar pathogen, has shown so...
ABSTRACT Direction-of-arrival (DOA) estimation is an important branch in the field of array signal processing. It can be applied in such fields as wireless communication, sonar, radar, biomedicine, and radio detection. This fact together with the development of the geometries used in the past years is the principal motivation of this research project. Although various studies have focused on the uniform hexagonal array for direction finding, there is scanty use of the uniform hexagonal array ...
ABSTRACT Sugarcane productivity in Kenya has declined despite increased acreage and new cultivars possibly due to use of old-cultivar agronomic inputs. The N-K2O optimal rates for new cultivars are unknown. Kenya Sugar Industry intends to pay farmers based on sucrose instead of tonnage however, factors that influence productivity e.g. N-K2O rates and harvesting age have not been evaluated. Foliar analysis is a diagnostic tool, but has not been embraced. The objective was to compare variations...
ABSTRACT Plastic pollution has recently gained global concern due to the negative effect it presents on both the environment and human health. In the environment, plastics degrade yielding millions of micro- and nano-scale plastic particles. The microplastics have the ability to adsorb organic pollutants, heavy metals, and micro-organisms in either the aquatic or terrestrial environments. The microplastics size range and ubiquity in the environment provides an easy pathway into the food chain...
ABSTRACT Completely positive maps is an important eld due to its signicance, application and mathematics itself. While discussing the properties of the positive maps, researchers have questioned whether the properties of the positive maps also hold for completely positive maps. In chapter 1, we have started with a C-algebra A, generated on A other C-algebras and then investigated these forms of C-algebras. We investigated whether the properties of A such as self-adjointedness and completeness...
ABSTRACT Inflation is increasingly becoming an important parameter that determines financial performance of central banks worldwide. Although many empirical studies have used time series and vector auto regression models to analyze inflation, very few studies have relied on the predictive ability of the logistic model which has a more intuitive interpretation for key issues such as drivers of inflation. The primary concern for every country is growing expectations about inflation which has re...
ABSTRACT Despite more than a century of efforts to eradicate and control malaria, it still remains a major risk to public health and economies of countries in the tropical and subtropical regions of the world. Control of malaria has been based on eradication of the vector, mosquito, by use of pesticides. In order to reduce malaria incidence, some African countries are re-introducing the banned dichlorodiphenyltrichloroethane (DDT), however, organophosphates are known to have far more immediat...
Abstract. This study is a critical review of theoretical issues that underline the linear mixed effects (LME) and nonlinear mixed effects (NLME) models. These two areas are revisited under maximum likelihood and restricted maximum likelihood 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-dat...
ABSTRACT The prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency and sickle cell trait (SCT) may vary within very close localities in malaria endemic areas due to dynamics in malaria incidence and demographics. Immunoglobulin-G (IgG) antibodies against Plasmodium falciparum (Pf) circumsporozoite protein (CSP) and apical membrane antigen-1 (AMA1) confer protection against malaria. Both G6PD deficiency and SCT increase resistance to Pf malaria and it is not well understood if this...
ABSTRACT Mineral data shows several deposits of copper and titanium minerals in Kenya yet the country continues to import copper and titanium products. In some regions of Tharaka Nithi County, occurs ores that are known to contain both copper and titanium minerals. These minerals have never been earmarked for extraction mainly because the common methods known for extraction are expensive. In addition, the hydrometallurgical or pyrometallurgical process used in copper extraction releases green...