Burian A.,University of Vienna |
Schagerl M.,University of Vienna |
Yasindi A.,Egerton University
Hydrobiologia | Year: 2013
We investigated the feeding behaviour of the dominant microzooplankton of saline lakes in the East African Rift Valley. A set of grazing experiments revealed high ingestion rates of the two euryhaline rotifers Brachionus dimidiatus and Brachionus plicatilis and of the large-sized omnivorous ciliates Frontonia sp. and Condylostoma magnum reflecting the unique nature of tropical saline systems. The size spectrum of ingested particles was broad and even included filamentous cyanobacteria such as the commonly dominating Arthrospira fusiformis. Feeding selectivity on cyanobacteria, however, was rather low showing higher values for cryptomonads and small ciliates. Bacterial biomass was favoured by the presence of grazers, as small bacterivorous predators were reduced at an average of 13. 9%, showing the cascading effect of large zooplankton on the food web structure. Overall, based on this first-time study of the microzooplankton feeding behaviour in East African soda lakes, a strong structuring effect of rotifers and large ciliates on microbial plankton communities is assumed, especially in times of high consumer biomass. © 2012 The Author(s).
King'ori A.M.,Egerton University
International Journal of Poultry Science | Year: 2011
Poultry production at all scales of operation is wholly dependent on the supply of day-old chicks. Fertility and hatchability are two major parameters that highly influence the supply of day-old chicks. Fertility refers to the percentage of incubated eggs that are fertile while hatchability is the percentage of fertile eggs that hatch. It is therefore important to understand the factors that influence fertility and hatchability of eggs. For the hatchability traits, breed has little effect on hatchability of poultry eggs, although light breeds have been reported to have higher fertility and hatchability. The diet of breeder poultry should be adequate in both quality and quantity to meet the recommended levels set out in the feed standards for the category. The most influential egg parameters that influence hatchability are: weight, shell thickness and porosity, shape index (described as maximum breadth to length ratio) and the consistency of the contents. Heat stress reduces the external and internal egg qualities. Heat stress affects all phases of semen production in breeder cocks. Hatchability for small eggs is lower compared to that of medium and large eggs. There are many factors contributing to the failure of a fertile egg to hatch which include lethal genes, insufficient nutrients in the egg and exposure to conditions that do not meet the needs of the developing embryo. Breeder factors that affect hatchability include strain, health, nutrition and age of the flock, egg size, weight and quality, egg storage duration and conditions. The optimum temperature range for poultry is 12-26°C. Fertile eggs should not be stored for more than 10-14 days, after 14 days of storage; hatchability begins to decline significantly. The position (large end up or vice versa) of egg storage influences hatchability. Eggs stored with the small end up have higher hatchability as compared to the large end up. Incubation of fertile eggs can be done naturally by a broody hen or in an incubator. The broody hen provides the fertile eggs with optimum environmental conditions (temperature, egg turning and humidity) to stimulate embryonic development until hatching. The incubator is a simulated artificial design that mimics the broody hen's role of providing fertile eggs with optimum environmental conditions (temperature, egg turning and humidity) to stimulate embryonic development until hatching. A constant incubation temperature of 37.8°C is the thermal homeostasis in the chick embryo and gives the best embryo development and hatchability. Mortality is seen if the temperature drops below 35.6°C or rises above 39.4°C for a number of hours. Egg turning during incubation is critical for successful hatching and influences hatchability. No turning of eggs during incubation results in low hatchability and delays hatch by a few days. © Asian Network for Scientific Information, 2011.
Kiboss J.K.,Egerton University
Journal of Educational Computing Research | Year: 2012
Achievement in mathematics is an issue of great concern not only to students and parents but also to employers and researchers in Kenya. This is because the Kenya National Examination Council (KNEC) has continuously reported dismal results in this area, and especially in geometry. Also, KNEC indicates that it presents difficulties to both the teachers and learners during instructional sessions. In an extension of research demonstrating causal effects of electronic learning environments on special education learners' achievement and perceptions of mathematics instruction, the present study experimentally examined the effectiveness of a special electronic learning program (SELP) to improve hearing-impaired learners' achievement of basic geometry and their perception of the Geometry learning environment. Sixty-six hearing-impaired learners from four special education schools situated in Rift Valley province were sampled purposively on the basis of the school's accessibility to participate in the study. The study employed the Solomon-Four Group Design research method. The specific dependent measures were the learners' achievement in geometry and their perception of the classroom learning environment. Measurement of achievement and perception were conducted using two instruments: (i) the Geometry Achievement Test (GAT), and (ii) the Special Learners Classroom Environment Questionnaire (SLCEQ). GAT's reliability was computed using K-R20 formula yielding a reliability of 0.78. On the other hand, SLCEQ reliability was determined using Cronbach alpha yielding a reliability coefficient of 0.82. The study established that SELP was modestly effective in improving the achievement of hearing-impaired learners on geometry and their perception of the classroom environment. The study concludes that teachers can arrest the special learners' problem of poor performance in geometry through the use of electronic learning programs. © 2012, Baywood Publishing Co., Inc.
Odadi W.O.,Mpala Research Center |
Karachi M.K.,Egerton University |
Abdulrazak S.A.,National Council for Science and Technology |
Young T.P.,Mpala Research Center |
Young T.P.,University of California at Davis
Science | Year: 2011
Savannas worldwide are vital for both socioeconomic and biodiversity values. In these ecosystems, management decisions are based on the perception that wildlife and livestock compete for food, yet there are virtually no experimental data to support this assumption. We examined the effects of wild African ungulates on cattle performance, food intake, and diet quality. Wild ungulates depressed cattle food intake and performance during the dry season (competition) but enhanced cattle diet quality and performance during the wet season (facilitation). These results extend our understanding of the context-dependent-competition-facilitation balance, in general, and are critical for better understanding and managing wildlife-livestock coexistence in human-occupied savanna landscapes.
Misati A.G.,Egerton University
Environmental Health and Preventive Medicine | Year: 2016
Objective: Contaminated drinking water can lead to the risk of intestinal and other infectious diseases that lead to high morbidity. Therefore, determining household safe water management practices will benefit billions of people by ensuring there is no recontamination. Methods: A cross-sectional study design was used and a sample of 346 households was selected through systematic random sampling. A questionnaire was then used which was based on the core questions on drinking water and sanitation for household surveys and descriptive analyses were performed for the collected data using SPSS. Results: Springs were predominantly used as the main source of water (97 %). Approximately, over half (58 %) of the sampled households never treated their drinking water to ensure that it was safe for drinking. Mostly (56 %), the households used jerricans for the storage of water with a majority of the households (95 %) covering their containers which were elevated from the reach of children in 52 % of the households. Conclusions: The risks included lack of water treatment, not covering the water container, risk of permitting dipping for those containers, lacking narrow neck and the risk of container being accessible to children. Basic treatment of the water at the household level by use of chemicals, filtration and boiling may have a great impact on the drinking water quality and health of the inhabitants of Kisii County. Also, creation of awareness on the possibilities of spring water being contaminated should be carried because of the assumption that spring water is safe and does not need to be treated. © 2016 The Japanese Society for Hygiene