Kimoloi S.,Masinde Muliro University of Science and Technology |
Rashid K.,Egerton University
Frontiers in Neuroscience | Year: 2015
Cerebral malaria (CM) is the most severe complication associated with Plasmodium falciparum infection. The exact pathogenic mechanisms leading to the development of CM remains poorly understood while the mortality rates remain high. Several potential mechanisms including mechanical obstruction of brain microvasculature, inflammation, oxidative stress, cerebral energy defects, and hemostatic dysfunction have been suggested to play a role in CM pathogenesis. However, these proposed mechanisms, even when considered together, do not fully explain the pathogenesis and clinicopathological features of human CM. This necessitates consideration of alternative pathogenic mechanisms. P. falciparum generates substantial amounts of ammonia as a catabolic by-product, but lacks detoxification mechanisms. Whether this parasite-derived ammonia plays a pathogenic role in CM is presently unknown, despite its potential to cause localized brain ammonia elevation and subsequent neurotoxic effects. This article therefore, explores and proposes a potential role of parasite-derived ammonia in the pathogenesis and neuropathology of CM. A consideration of parasite-derived ammonia as a factor in CM pathogenesis provides plausible explanations of the various features observed in CM patients including how a largely intravascular parasite can cause neuronal dysfunction. It also provides a framework for rational development and testing of novel drugs targeting the parasite's ammonia handling. © 2015 Kimoloi and Rashid.
Uzayisenga R.,Tianjin University of Traditional Chinese Medicine |
Uzayisenga R.,Ministry of Health |
Ayeka P.A.,Tianjin University of Traditional Chinese Medicine |
Ayeka P.A.,Egerton University |
Wang Y.,Tianjin University of Traditional Chinese Medicine
Phytotherapy Research | Year: 2014
Herbal medicines have traditionally played a major role in the management of diabetes in Asian countries for centuries. Panax notoginseng (Burk) F. H. Chen (Araliaceae) known as Tiánqī or san qi is a well-known medicinal herb in Asia for its long history of use in Chinese medicine. Qualified as 'the miracle root for the preservation of life', it has been used in China for 600 years, for treatment of various diseases. Panax notoginseng saponins (PNS) are the key active components. PNS have been widely used in China for treatment of cardiovascular diseases. However, scientific studies have shown a wide range of other pharmacological applications including anti-cancer, neuroprotective and anti-inflammatory agents, immunologic adjuvant and prevention of diabetes complications. Recently, hypoglycemic and anti-obesity properties of PNS have also been demonstrated. The present review highlights the effects of PNS on glucose production and absorption, and on inflammatory processes that seem to play an important role in the development of diabetes. Copyright © 2013 John Wiley & Sons, Ltd.
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.
Agency: European Commission | Branch: FP7 | Program: CP-FP-SICA | Phase: ENV.2010.3.1.1-3 | Award Amount: 2.48M | Year: 2011
There are a large number of small communities and towns in Africa that suffer from severe problems with water supply and sanitation. Small communities in rural areas and peri-urban areas of small towns have comparable settlement structures in which reuse of water and use of sanitation products can be utilized. However, there is only limited local capacity to adopt, implement and operate integrated water supply and sanitation. CLARAs overall objective is to strengthen the local capacity in the water supply and sanitation sector. From a technological point of view, existing low cost technologies for decentralized water supply and sanitation systems shall be assessed and adapted for African conditions with the focus on reducing risks in use and reuse of water and sanitation products, and providing demand oriented water quality. Based on these technological improvements and the experiences from the FP6 projects ROSA and NETSSAF, a simplified planning tool for integrated water supply and sanitation systems for small communities and peri-urban areas shall be developed that incorporates the key factors for success, i.e. operation and maintenance issues and reuse potential, form the beginning of the planning process, and that can be tailored to available local capacities. This simplified integrated CLARA planning tool shall then be tested and evaluated in different geographical African regions to incorporate different economic, cultural and social boundary conditions. For the communities participating in the planning process, application documents will be prepared as a final output that serve as basis to ask for funding of their implementation plans for integrated water supply and sanitation.
Olang L.O.,Egerton University |
Furst J.,University of Natural Resources and Life Sciences, Vienna
Hydrological Processes | Year: 2011
The impacts of historical land cover changes witnessed between 1973 and 2000 on the hydrologic response of the Nyando River Basin were investigated. The land cover changes were obtained through consistent classifications of selected Landsat satellite images. Their effects on runoff peak discharges and volumes were subsequently assessed using selected hydrologic models for runoff generation and routing available within the HEC-HMS. Physically based parameters of the models were estimated from the land cover change maps together with a digital elevation model and soil datasets of the basin. Observed storm events for the simulation were selected and their interpolated spatial distributions obtained using the univariate ordinary Kriging procedure. The simulated flows from the 14 sub-catchments were routed downstream afterwards to obtain the accrued effects in the entire river basin. Model results obtained generally revealed significant and varying increases in the runoff peak discharges and volumes within the basin. In the upstream sub-catchments with higher rates of deforestation, increases between 30 and 47% were observed in the peak discharge. In the entire basin, however, the flood peak discharges and volumes increased by at least 16 and 10% respectively during the entire study period. The study successfully outlined the hydrological consequences of the eminent land cover changes and hence the need for sustainable land use and catchment management strategies. © 2010 John Wiley & Sons, Ltd.
Carroll M.R.R.,Royal Surrey County Hospital Foundation Trust |
Seaman H.E.,Egerton University |
Halloran S.P.,Egerton University
Clinical Biochemistry | Year: 2014
Worldwide, colorectal (CRC) is the third most common form of cancer, after lung and breast cancer, and the fourth most common cause of cancer death, although in developed countries CRC incidence is higher and it accounts for an even higher proportion of cancer deaths. Successful treatment of early-stage CRC confers substantial survival advantage, and there is now overwhelming evidence that screening average-risk individuals for CRC reduces the incidence and disease-specific mortality. In spite of considerable research for new biomarkers for CRC, the detection of blood in faeces remains the most effective screening tool. The best evidence to date for population-based CRC screening comes from randomised-controlled trials that used a guaiac-based faecal occult blood test (gFOBt) as the first-line screening modality, whereby test-positive individuals are referred for follow-up investigations, usually colonoscopy. A major innovation in the last ten years or so has been the development of other more analytically sensitive and specific screening techniques for blood in faeces. The faecal immunochemical test for haemoglobin (FIT) confers substantial benefits over gFOBt in terms of analytical sensitivity, specificity and practicality and FIT are now recommended for CRC screening by the European guidelines for quality assurance in colorectal cancer screening and diagnosis. The challenge internationally is to develop high quality CRC screening programmes for which uptake is high. This is especially important for developing countries witnessing an increase in the incidence of CRC as populations adopt more westernised lifestyles. This review describes the tests available for CRC screening and how they are being used worldwide. The reader will gain an understanding of developments in CRC screening and issues that arise in choosing the most appropriate screening test (or tests) for organised population-based screening internationally and optimising the performance of the chosen test (or tests). Whilst a wide range of literature has been cited, this is not a systematic review. The authors provide FOBT CRC screening for a population of 14.6 million in the south of England and the senior author (SPH) was the lead author of the European guidelines for quality assurance in colorectal cancer screening and diagnosis and leads the World Endoscopy Organization Colorectal Cancer Committee's Expert Working Group on 'FIT for Screening'. © 2014 The Canadian Society of Clinical Chemists.
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.
King'ori A.M.,Egerton University
International Journal of Poultry Science | Year: 2011
This study was conducted to find out the multiple uses of eggshells in nutrition and medicine. Eggshells can be utilized for various purposes that minimize their effect on environmental pollution. Eggshells present healthy, balanced calcium due to its trace amounts of other minerals and is probably the best natural source of calcium. One whole medium sized eggshell makes about one teaspoon of powder, which yields about 750-800 mgs of elemental calcium plus other micro elements. Eggshell powder has been reported to increase bone mineral density in people and animals with osteoporosis. In laying hens in the late production phase, eggshell powder has been found to increase egg production and improve the quality of shells. Discarded eggshells are often used as a plant fertilizer and are effective liming sources. This is because eggshells contain calcium that raises, or neutralizes, the pH level of overly acidic soil. Chicken eggshells can be used as an alternative soil stabilizer like lime since they have the same chemical composition. Such stabilized soil can be used as subgrade materials in road construction works. Eggshell membrane consists of collagen as a component. Collagen is a type of protein, fibrous in nature that connects and supports other bodily tissues, such as skin, bone, tendons, muscles and cartilage. Collagen has been isolated mainly from bovine and swine skins and bones Collagen used in medicine, biochemical, pharmaceutical, food and cosmetics industries. After the outbreaks of bovine spongioform encephalopathy, foot and mouth disease, autoimmune and allergic reactions, restrictions on collagen uses from these sources were enforced. Eggshell membrane collagen is very low in autoimmune and allergic reactions as well as high in bio-safety and is of similar characteristics to other mammalian collagen. Eggshells/shell membranes have multiple uses in nutrition, medicine, construction and art works. © Asian Network for Scientific Information, 2011.
Adung'a V.O.,University of Cambridge |
Adung'a V.O.,Egerton University |
Gadelha C.,University of Cambridge |
Field M.C.,University of Cambridge
Traffic | Year: 2013
Endocytosis is a vital cellular process maintaining the cell surface, modulating signal transduction and facilitating nutrient acquisition. In metazoa, multiple endocytic modes are recognized, but for many unicellular organisms the process is likely dominated by the ancient clathrin-mediated pathway. The endocytic system of the highly divergent trypanosomatid Trypanosoma brucei exhibits many unusual features, including a restricted site of internalization, dominance of the plasma membrane by GPI-anchored proteins, absence of the AP2 complex and an exceptionally high rate. Here we asked if the proteins subtending clathrin trafficking in trypanosomes are exclusively related to those of higher eukaryotes or if novel, potentially taxon-specific proteins operate. Co-immunoprecipitation identified twelve T. brucei clathrin-associating proteins (TbCAPs), which partially colocalized with clathrin. Critically, eight TbCAPs are restricted to trypanosomatid genomes and all of these are required for robust cell proliferation. A subset, TbCAP100, TbCAP116, TbCAP161 and TbCAP334, were implicated in distinct endocytic steps by detailed analysis of knockdown cells. Coupled with the absence of orthologs for many metazoan and fungal endocytic factors, these data suggest that clathrin interactions in trypanosomes are highly lineage-specific, and indicate substantial evolutionary diversity within clathrin-mediated endocytosis mechanisms across the eukaryotes. © 2013 John Wiley & Sons A/S.