PT-school of Pure and Applied Sciences

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Accessibility of anal cleansing materials for public primary school pupils in Kajiado North sub county, Kenya.
(Kenyatta University, 2014-09-25) Sabla, Abduba Umuro
Anal, cleansing is the hygienic practice of cleaning anal area after defecation; it is an important aspect of personal hygiene as it contributes to prevention of enteric and .respiratory infections; 'Use of inadequate anal cleansing materials leads to hand contamination which leads' to transfer .of ' disease causing organisms to 'the body systems, this increases the risk of intestinal parasites infestation and diarrheal diseases. Different materials are used for anal cleansing depending generally on accessibility and specifically on affordability, availability, acceptability, physical location of the materials and one's social-demographic characteristics. Corumon materials used for anal cleansing are tissue paper, stones, leaves, newspapers among others and water used by Muslims. Discussion around these materials has been neglected by researchers and Water Sanitation and Hygiene programme implementers. Observation in most of the schools in Kajiado North Sub County shows shortage of anal cleansing materials and gaps ill sustainability of access of such materials as indicated by smearing of faeces on Iatrine walls. The study will be conducted in public primary schools in Kajiado North Sub County. School pupils are affected by the issue because of their age and limited instruction from their school administration on which materials to use for anal hygiene. The main objective of the study is to determine accessibility of anal cleansing materials for pupils in public primary schools Kajiado North Sub County. Current situation access, social demographic and institutional factors influencing access and choice, and sustainability of the same will also be assessed. Descriptive cross sectional study design will be used, sampling will be done by stratified random sampling technique to select schools from zones and pupils from .selected schools by age and gender. Mixed method of data collection will be' used and analyzed using Statistical Package for Social Sciences version. The study will shed light on the extent to which pupils have access to anal cleansing materials in the Sub County and findings will inform strategies for increased accessibility and sustainability, and options to be adopted in schools at county and national levels by informing policy formulation and strategic planning. Findings will be presented the form of text, charts, graphs and tables.
Analysis of bovigam and tuberculin tests in detection of bovine tuberculosis in cattle in Laikipia County and associated risk factors
(Kenyatta University, 2014-10-03) Mochere, Nyanchoka Lydia
Bovine tuberculosis (BTB) is an infectious disease of cattle caused by the bacterium Mycobacterium bovis which can also infect and cause tuberculosis in other mammals including goats, pigs, dogs and cats. The disease is an important zoonosis worldwide that has been emerging and re-emerging in different ecological scenarios. Amongst livestock the disease is most commonly associated with cattle and has a large economic significance. As a zoonotic disease, bovine tuberculosis is also a threat to public health where consumption of infected unpasteurized milk and other dairy products can be a source of human infection. However, exposure to aerosols containing Mycobacterium bovis is also likely to be an important risk factor for bovine tuberculosis in humans. Despite huge global efforts in tuberculosis control, pastoral areas remain under-investigated. Bovine tuberculosis has been extensively studied in countries neighboring Kenya. Little research has been done in Kenya concerning bovine tuberculosis and yet the disease causes major economic losses on animal productivity and human transmissions constitute a major public health concern. This study aims at detecting bovine tuberculosis in live cattle in Laikipia County by use of comparative intradermal tuberculin and bovigam tests and then compare results obtained from the two methods. This will involve sampling a total of 753 cattle from the sampling sites (Laikipia North, East and South). Animals aged six months and older will be selected for sampling. Ear tags and nail vanish will be used to identify test animals. The animal will then be shaved using a scapel two areas of 2 em, 12 em apart at the mid neck region of the animal. The thickness of the skin will be measured with a digital calliper and disinfected with 70% ethanol. Four (4) mls of venous blood will then be drawn from the animal after shaving and disinfection of the area in a vacutainer containing heparin, packaged in temperature controlled delivery boxes. 0.25 ml of the blood will be inoculated with 25 ul, bovine and avian purified protein derivatives and incubated at 37°C overnight within 24 hours of collection. Plasma supernants will then be harvested after incubation, stored at -20°C and then transported to the laboratory for quantification with sandwich ELISA using the commercially available BOVIGAM®Plate Kit. Intradermal injection of 0.1 ml (2,500 IV/ml) bovine purified protein derivative and 0.1 ml (2,500 IV/ml) avian purified protein derivative will be made in two shaved sites. In young animals in which there will be no room to separate the sites sufficiently on one side of the neck, injection shall be made on each side of the neck at identical position in the centre of the middle third of the neck. Skin thickness will be measured again at both injection sites after 72 hours. The reaction at each site will be derived as the difference of the skin thickness after 72 hours minus before injection. Data will be analysed by Statistical Package for Social Science software utilizing Chi-square analysis to test fOFrates of reactors according to study site, breed, sex, age and herd size obtained from comparative intradermal tuberculin test and bovigam (interferon gamma test). Descriptive analysis will be utilized where applicable. The findings from this study will be important as they will shed light on the presence of bovine tuberculosis in live cattle.
Application of Genetic Engineering Approach in the Control of Cassava Brown Streak and Bacterial Blight Diseases
(2013-12-14) Njiru, J. M.; Mgutu, Allan Jalemba; Tripathi, L.
Cassava is the fifth most important food crop in the world. Cassava's importance in Africa and South America can't be overstated. As a drought-tolerant crop that does well in poor soils, it enhances household food security and is a source of income that provides livelihood to 800million people globally. Annual global production of cassava is estimated at 232 million tonnes; an average yield of 12.5 tonnes per hectare. Diseases and pests are the greatest biotic problems to cassava production across the East" and Central Africa (ECA) sub-region causing yield losses. Cassava bacterial blight (CBB) caused by Xanthomonas axonopodis pv. manihotis (Xam) is the most destructive bacterial disease in all cassava growing areas of the world causing yield losses of about 50% to 75%. Cassava is vulnerable to at least 20 different viral diseases, cassava brown streak disease (CBSD), being one of the most important viral diseases in Africa. CBSD is more lethal than other cassava viral disease because it causes severe necrosis within the edible storage roots. Crop improvement efforts through conventional breeding have aimed at attaining CBSD and CBB resistance, however these efforts have been largely unsuccessful due to the nature of the cassava plant for example poor flowering and low pollen fertility. This study aims at generating CBB and CBSD resistant plants through genetic engineering. Hypersensitivity response assisting protein (Hrap) gene will be used for transforming cultivar 60444. The constitutive expression of the Hrap in plants generates durable resistance against plant bacterial pathogens. This study seeks to use the Hrap gene to generate CBB resistance in cassava. There is no robust genotype-independent transformation protocol that has been developed for African farmer preferred cultivars. Through this study :;t protocol for transformation of three farmer preferred cultivars (TME 14, Mkombozi, Albert) using friable embryogenic callus (FEC) as the explant will be optimized, then transform one of the cultivars for resistance against CBSD using the optimized protocol. Post-transcriptional gene silencing (PTGS) offer significant potential for controlling RNA plant viruses like CBSD. Therefore this study aims at using the RNA interference (RNAi) approach in developing CBSD resistant lines. The presence, integration and expression of the transgenes will be confirmed by PCR, Southern blot and RT-PCR analysis followed by screen house evaluation to gauge resistance. Data on different stages of optimization during transformation and regeneration will be collected and analysed by ANOV A (p<0.05) and means will be separated using LSD (p<0.05). For FEC and cotyledon induction a completely, randomized design (CRD) will be used for all experiments with the FEC as the observation unit and the plate as the replicate. At list three replicates will be set per experiments. The regeneration Frequency (RF) and transformation frequency (TF) of all the cultivars will be determined
Assessment of butyltin compounds in water and sediment matrices along Kilindini harbour, Mombasa county Kenya
(Kenyatta University, 2014-10-03) Mulima, Henry
Tributyltin (TBT) is an organotin compound used primarily as biocide in antifouling paints to prevent colonization by barnacles and drag-inducing taxa on ship hulls. It is extremely toxic to aquatic life and it is an endocrine - disrupting chemical that causes severe irreversible reproductive effects in aquatic organisms such as imposex. Human toxicology of tributyltins include, disturbance of smell sense, neural necrosis, hepatic lesions and interference with immune system. The TBT is relatively stable and resistant to natural degradation in water and sediment. Because of its chemical properties and wide spread use as antifouling agent, concerns have been raised over the risks it poses to both freshwater and salt water organisms. Therefore, continued monitoring and control of TBT in water ways is necessary all over the world. The TBT derivatives include monobutyltin (MBT) and dibutyltin (DBT) which are used as heat and light stabilizers in manufacture of PVC and polyurethane foams. Kilindini harbor has been receiving ships since 1896, and is the gateway to Eastern Africa. There is thus a high chance of TBT and its derivatives being found in the harbor. Studies on TBT and its derivatives along Kenyan coastline have not been reported. Therefore the study proposes to determine TBT and its derivatives in water and sediments at the Kilindini harbour. Purposive study design will be used in sampling. The water and sediment samples will be collected from Kilindini harbor and analyzed for TBT, DBT and MBT using gas chromatography-mass spectrometry (GC-MS). The data will be analyzed using special excel software computer package and analysis of variance (ANOVA) used to determine the variation in the levels of TBT and its derivatives in water and • sediment matrices. The results will be availed to relevant authorities and used to sensitize the public.
Bacterial profile of' bacteremia and septicemia among children under five years visiting Kisii Level 5 hospital in Kisii county, Kenya
(2014-07-28) Mokua, Evans Chakua; Maingi, J.M.
Bacteremia and septicemia in children is an important cause of mortality and morbidity. It is among the most common health-care associated infections. In recent years, bacteremia and septicemia infections in children less than five years have been on the increase due to infections that occur without localized signs or focus of infection, for example, typhoid and non-typhoid Salmonella infections that are a common cause of bacteremia or those infections whose localized signs develops later. These infections are treated using first line antibiotics such as Ampicillin, Chloramphenicol, and Nalixidic acid, Streptomicin, Sulfixozasole, and Tetracycline. However, multi-drug resistance is an increasing problem. The aim of this study will be to describe the frequency of occurrence of etiological isolates of bacteremia and septicemia and their antimicrobial susceptibility patterns at Kisii hospital levelS in Kisii County, Kenya. This crosssectional study will be carried out at Kisii hospital levelS for children below five years. In this study, about 150 patients will be enrolled. Blood collected will be cultured, sub cultured and isolates identified by standard conventional methods such as colonial morphology, Gram stain method, and confirmed by biochemical tests. The frequency of the various bacterial isolates will then be determined. The antimicrobial susceptibility of the isolates will be tested using the disk diffusion method according to Clinical and Laboratory Standard Institute. Data collected will be analyzed using appropriate biostatical tools and will be used in future management of the bacteremia and septicemia infections.
Behavioural and environmental highland malaria risk factors analysis in Nyamira North district, Nyamira County
(Kenyatta University, 2014) Okonji, Gilbert, Asilenje
Malaria is caused by protozoan parasites of the genus Plasmodium. It is one of the leading causes of illness and death and one of the most important causes of human morbidity and mortality with enormous medical, economic and emotional impact in the world. Estimates indicate that there were about 207 million cases of malaria and an estimated 627 million deaths. Nyamira North District lies in the western Kenya highland and is known to be a malaria epidemic area with unstable transmission of varying seasonality. The highest peak of malaria transmission is usually reached between May - July and November-January periods preceding the short and long rain seasons. The current study aims to investigate the correlation between environment and household's knowledge, attitudes and practices with malaria epidemics in Nyamira North District. 890 participants of all ages (all-age cohort) from the study area will be enrolled. Data on environmental, socio-demographic, and economic factors will be collected from 21villages systematically selected. Environmental data will be collected from Olobal Positioning System (OPS) measurements. The dwelling in which the participant normally sleep will be assessed and distances to mapped forest edge, swamps, rivers, roads, and health centers will be calculated. Type of vegetation within 200 m of the house will be recorded. The presence and type of slope will also be determined. A questionnaire will be orally administered to ascertain socio-demographic, economic and behavioral characteristics. To establish whether there is any statistical relationship between the mentioned variables and malaria prevalence, Pearson Chi- square test will be used. An association between the two variables will be considered significant if the p value~0.05. Data generated by the study will be used by the Ministry of health in future control strategies for highland malaria in Nyamira North district.
Capacities and efficiencies of electrospun titania nanofibers in removing organic dyes and pesticides from contaminated water
(2014-07-28) Chepngetich, Josphine; Mbuvi, Harun M.
The release of organic dyes and pesticides into water bodies by paint factories and flower farms results in the degradation of both water quality and aquatic life. A complete water treatment system may consist of the application of a number of physical, chemical and biological processes to the waste water. These current water treatments are ineffective in completely removing pollutants; they are not accessible to rural majority facing the challenge of access to clean drinking water, beyond reach to most consumers and cannot be recycled. This work describes the use of nanotechnology in water treatment and environmental remediation. We exploit the use of titaniananofibers as the remediation agent because of its high reduction and oxidation potentials. The high redox potentials can reduce or oxidize any organic and pesticides present in polluted water under sunlight irradiation. The titaniananofibers will be prepared by electro spinning process of titania precursors dissolved in a suitable polymer followed by calcinations. Titanium dioxide fibers will be characterized for morphology and structure by Scanning Electron Microscopy and aspect ratio by Branuer-Emmet-Teller (BET) analysis. UV-visible spectroscopy and high performance liquid chromatography is used to monitor the rate of photodegradation and their products respectively. The developed technique can be used in rural areas and small scale industries to treat water before releasing it to the environment.
Characterization of cdxsel_xs/cu2sp-n junction for solar cell application deposited by chemical bath deposition method
(2014-07-30) Njeru, Ephantus Nyaga; Munji, M. K.; Njoroge, W. K.
The rapid growth in technology has led to a very high demand for renewable sources of energy which can be accessed by everyone irrespective of one's locality. CdS has so far proved to be a good window material when matched with CU2Sas an absorber material of the P-N junction for solar cell application. This research entails the doping of the Cadmium sulphide with selenium so as to enhance optoelectric properties. Cd-Set.sS films will be deposited using the CBD method. Chemicals to be used for this are; solutions of pure ammonium nitrate, thiourea, sodium selenosulphate and cadmium nitrate. Solutions of 0.004M cadmium nitrate, 0.008M ammonium nitrate, and 0.008M thiuorea in deionised water will be prepared, stirred till all the particles are dissolved and 20m1of each solution will be taken into a separate beaker. Doping of the CdxSel-xS films will be done by varying volumes of uniform concentration of sodium selenosulphate (Na2SeS03) solutions by volume at a constant deposition temperature of 80°c. The best value of x realised will be maintained as the deposition temperature is varied from 60°c to 90°c. Deposition of CU2Sfilm on a glass substrate will require the following Chemicals; copper sulphate, hydrochloric acid, thiourea, and tartaric acid solutions of analytical grade. At a constant temperature of 80°C, deposition of CU2Sfilms will be done as follows; 25mL of copper sulphate will be complexed with 25ml of O.2M tartaric acid in a beaker, and then 25ml of 0.2M thiourea will be mixed in it with constant stirring. The pH will be adjusted to 3 by addition of dilute hydrochloric acid with constant stirring using the pH meter. The cleaned glass substrate will be immersed vertically into a beaker and the deposition process will be carried out at different solution concentrations of CUS04 in order to determine the optimum conditions for the deposition of Cu2S thin films. The best concentration of CuS04 will be maintained as the deposition temperature is varied from 60°c to 90°c. The optical analysis of the thin films deposited above will be done using UVVIS NIR 3700 spectrometer while the sheet resistivity will be done using the four point probe method. Optical properties like reflectance and transmittance measured using UVVIS NIR 3700 spectrophotometer will be used to calculate others optical properties like band gap (Eg), refractive index (n), extinction coefficient (k) and absorbance (a). The results will be analysed to determine how optical conductance, transmittance, absorbance and the electrical resistivity varies with the conditions of deposition using the Scout software. Finally the optimal values of CdxSel-xS and CU2S will be used to fabricate (CdxSel_XS/CU2S)P-N junction for solar cell application. The solar cell P-N junction will be characterized using the solar celJ simulator to find it's I-V characteristics and parameters like fill factor (FF), conversion efficiency (11), and open circuit voltage (V00)'
Characterization of cuo/zno:ai p-n junction for solar cell application
(2014-07-31) King' ang'i, James Mwiti; Munji, M. K.
Solar cells with high efficiency and low price have long been desired. However the commercially available solar cells are still of low efficiencies and expensive. Various elements and compounds are used to fabricate thin film semi-conductors for solar cell application. However insufficient literature and data is available on the use of CuO and ZnO:Al for solar cell application especially by use of spray pyrolysis technique. In this research CuO and ZnO:Al thin films will be prepared by spray pyrolysis. In order to obtain different samples of CuO, deposition temperature will be kept constant first while solution molarity will be varied from O.3M to 0.45M. Each of the samples will be characterized separately in order to obtain the solution molarity which gives the best optical and electrical characteristics. Secondly, the optimised solution molarity will be kept constant and the deposition temperature will be varied from 2500 to 4000 in order to obtain more samples of CuO prepared at different temperatures. Each of the samples will also be characterized separately in order to obtain the sample which gives the best optical and electrical characteristics. To obtain the optimised conditions of ZnO:AI, initially the deposition temperature will be kept constant while doping percentage will be varied from 1% to 10% to obtain different samples of ZnO:AI thin films. Each of the samples will be characterized separately. The optimised doping percentage will be kept constant while deposition temperature will be varied from 2500 to 4000 in order to obtain more samples of ZnO:AI prepared at different temperatures. Each of these samples will be characterized separately in order to obtain the sample which gives the best optical and electrical characteristics. Optical properties of each of the above mentioned samples which include transmittance and reflectance will be measured using optical spectrum analyser and others which include refractive indices, absorption coefficients, dielectric constants and energy band gaps will be calculated using scouts software. Electrical characteristic which is the sheet resistivity will be obtained using four point probe method. The optimised conditions will be used in the fabrication of solar cell. In the fabrication of solar cell CuO will be used as absorber layer while ZnO:AI will be the window layer. After the solar cell has been fabricated, the CuO/ZnO:AI p-n junction will be characterised to obtain its current voltage characteristics using solar cell simulator. A graph of current against voltage will be plotted and from the graph solar cell parameters which includes open circuit voltage (Voe) and short circuit current (Ise) will be determined. Others which include conversion efficiency (11) and Fill factor (FF) shall be determined from measurements of current and voltage generated across the solar cell. The fabrication of CuO/ZnO:AI thin film solar cell is expected to offer reliable solution to design of solar cells with high efficiency from cheap and available resources
Characterization of p-s002: al in-zoo: al p-n Junction defosited by spray pyrolysis Technique for led applications
(2014-07-25) Onkundi, Paul Nyangaresi; Munji, M. K.; Bem, D. B.
Transparent zinc oxide (ZnO) and tin oxide (Sn02) are of great importance due to their various applications in opto-electronic devices. Tin oxide (Sn02) shows n-type conductivity. However when there is a suitable dopant doped with it the carrier conversion takes place and changes to p-type semiconductor. Aluminium doped (ZnO:AI) and undoped Zinc oxide (ZnO) shows n-type conductivity. In this study, ptype transparent conducting oxides of Sn02:AI and n-ZnO:AI thin films will be separately deposited on glass substrates by spray pyrolysis technique at different deposition temperatures and doping atomic percentages. Carrier gas pressure and substrate nozzle distance will also be varied. Optical characterization of the thin films will be done using optical spectrum analyzer. The data obtained will be used to calculate the transmittance, reflectance, absorbance, and the bandgap of the material. In electrical characterization IV characterization of the thin films will also be done to obtain rectifying current -voltage characteristics and the turn-on voltage. The optimized conditions of p-Sn02:AI and n- ZnO:AI will be used to prepare p-Sn02:AI /n-ZnO:AI PN junction. The resulting junction will be optically and electrically characterized for LED application.
Characterization of sns/cdxznl_xs thin film solar cell
(2014-07-25) Ntabo, Edward Omuga; Munji, M. K.
Semiconductors of group II-VI have potential applications in many technical fields, including solar cells and photo voltaic applications. Photovoltaic cells grown on glass substrates require p-type absorber thin films of optimum optoelectronic properties and ntype wide band gap thin films. The control of the composition of Cd1_xZnxSmay lead to the development of ideal materials for photovoltaic applications. Semiconducting Cd1_xZnxS materials and related ternary compounds are promising materials for high density optoelectronic applications. These applications are based on the structure of Cd1-xZnxS which exhibit fundamental absorption edges that can be varied. In solar cell systems, where CdS films have been demonstrated to be effective, the replacement of CdS with the higher band gap Cd1_xZnxSalloys has led to a decrease in window absorption loss and an increase in the short circuit current. In this research, zinc doped cadmium sulphide (CdxZnl_xS) thin films will be prepared by Chemical Spray Pyrolysis (CSP) technique on glass substrates and optimized. This will be done at different Zn doping percentages in CdS. On the other hand, SnS absorber layer will also be deposited using CSP technique and optimized from aqueous solutions on glass substrates. Samples of SnS will be prepared at different ratios and substrate temperatures. The film's electrical properties (resistivity) will be measured using <, the four point probe to determine their resistance. Optical properties like reflectance and transmittance will be measured by UV-V[S - NIR 3700 spectrophotometer type and used to calculate other optical properties like band gap (Eg) , refractive index (n), extinction coefficient (k) and absorbance (a). The results will be analyzed to determine how optical conductance, transmittance, absorbance and the electrical resistivity vary with the conditions of deposition using the Scout software. Conditions that give Cdl-xZnxS and SnS optimum optical properties will then be selected and used to fabricate a Cdl_xZnxS /SnS photovoltaic cell expected to give the highest efficiency. The photovoltaic cell's performance characteristics like short circuit current (Ise), open circuit voltage (Voe), fill factor (FF) and conversion efficiency (11) will be calculated from I-V curve plotted using a solar cell simulator.
Characterization of tin selenide: nickel-doped tin oxide prepared by spray pyrolysis for photovoltaic application
(2014-07-31) Mugambi, Nelson; Munji, M. K.
Thin film semiconductors of Sn.Se, and nickel doped Tin oxide are potential candidates for the development of future generation improved efficiency and low cost solar cell devices. This is due to their high absorption coefficient and good optical properties in the visible region of the solar spectrum. Nickel doped tin oxide and tin monoselenide thin films will be deposited using spray pyrolysis. Precursor solution will be prepared using a 0.05M Tin (II) Chloride (SnCI4.2H20) in de-ionized water and then being added in 100 ml ethanol to get equal proportions or to obtain a consistent balance of water and ethanol, followed by 1.5 weight percentage of nickel chloride 6-hydrate (NiCh.6H20).Thin films of tin selenide (SxSey) with atomic ratio y/x = 0.5 will be prepared on a glass substrate at deposition temperature, T=470°C using spray pyrolysis technique. The initial materials for the preparation of the films will be an alcoholic solution consisting of tin chloride Sncb.2H20 and 1,1-dimethl-2-selenourea (C3HgN2Se).Thin films of Sn02, Sn02: Ni, Sn.Se, and SnxSey- Sn02: Ni will be deposited on glass substrate using Spray pyrolysis. Spray pyrolysis deposition is a low-cost, up-scalable technique that allows obtaining thin (poly) crystalline films over large surface areas. The samples will be characterized by measuring their optical properties using UV-VIS-NIR spectrophotometer and will be used to calculate solid state and optical properties like band gap (Eg), refractive index (n) and absorbance (a). This will be analyzed to determine how optical conductance, transmittance, absorbance vary with the conditions of deposition using the Scout Software. Electrical characterization measurements especially sheet resistance will be done using four point probe method using Keithley 2400 Source Meter. Tin Selenide a p type and Nickel doped tin oxide n type deposited on a glass substrate will form a p-n junction. The diode characteristics such as short circuit current (Isc), open circuit voltage (Voc), fill factor (FF) and conversion coefficient (11) of the solar cell will be determined. Tin selenide (SnxSey) and nickel doped tin oxide (Sn02: Ni) semiconductor have an important role in solar cell devices. Its fabrication is expected to be cost effective and of improved solar conversion efficiency
Comparison of microscan walka way 40 plus and bruker maldi biotyper systems for identification of enteric pathogens in Kenya
(2014-08-13) Rono, Franklin Kipyegon
Enteric bacteria pathogens is a group of microbes that are responsible for causing bacterial gastroenteritis which is a condition that is characterized by diarrhea, vomiting, abdominal pain and cramping. The pathogens are a public health concern due to the increased rates of morbidity and mortality. In a clinical microbiology laboratory, the current method of identifying bacterial isolates is mainly based on phenotypic characterization and biochemical testing. These techniques are costly and time-consuming so new technologies are now being considered for pathogen identification and susceptibility profiling. This study will compare the performance and agreement of the Bruker MALDI Biotyper and the MicroScan WalkAway 40 Plus technologies for diagnosing enteric pathogens. A total of 104 bacterial isolates obtained from previously collected stool samples used for surveillance of enteric pathogens will be randomly selected from the Microbiology Hub Laboratory sample archive. A fresh culture of the bacteria will be generated and then characterized using the Bruker MALDI Biotyper and MicroScan WalkAway analyzers. Results from the two systems will be compared and the outcome indicators to be assessed will include turnaround time, system capability, test and acquisition cost and percent agreement at the genus and species level. Validation of the Bruker MALDI Biotyper and MicroScan WalkAway 40 Plus techniques will result in introduction of methods that creates scope for rapid, reliable, and cost savings strategies.
Computational and optoelectronic studies of rare earth metals doped titania for photochromic applications
(Kenyatta University, 2014-11-28) Osoro, Mosiori Geoffrey
Nanofabrication of Ti02 makes it useful in varieties of applications like photocatalysis, photochromic devices, self-cleaning coatings, fog proof glass and water purifier. Titanium (IV)-oxide occurs in nature in three mineral forms: anatase, brookite and rutile. All three forms are characterized with high refractive index, low absorption and low dispersion in visible and near-infrared spectral regions, high chemical and thermal stabilities. This important metal-oxide semiconductor with relatively wide band gap (3.25 eV for anatase, 3.0 eV for rutile, 1.9 eV for brookite) and low phonon energy «700 em") is an excellent host for various rare earth (RE) impurities providing their efficient emission in visible range. These systems are of possible interest in white light emission diode (LED) industry, photocatalysts and photochromic applications. At the same time, being non-toxic and biocompatible, rareearth doped anatase has strong potential to replace standard types of fluorophores (quantum dots, organic dyes, etc.), traditionally used as fluorescent markers in medicine and biological applications. Titanium and Rare earth doped Ti02 nanoparticles will be synthesized by sol gel and wet precipitation method. Theoretical optical properties will be estimated by density functional theory (DFT) using quantum EXPRESSO software, which will be corroborated with experimental data. Morphological and structural properties will be characterized by Scanning electron microscope (SEM), transmission electron microscope (TEM) Energy dispersive X-ray (EDX), X-ray diffraction (XRD), UV-visible spectroscopy, Fourier Transform infrared (FTIR) spectroscopy and photolumnisce spectroscopy.
Determination of natural radioactivity and essential elemental concentration levels in the vicinity of minjingu mining - Tanzania
(Kenyatta University, 2014-10-03) Herman, James
The international body known as the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) periodically reviews the effects of ionizing radiation on the environment. Last year, the Committee, for the first time, issued a report that contained a review specifically focused on the effects of ionizing radiation on plants and animals. While the review contained no surprising findings, it does serve to focus attention on the changing nature of the scientific community's assessment of radiation's potential environmental effects. The release of radioactive wastes to the environment is known to increase the radiation exposure to humans. Minjingu, as one of the largest phosphate mine in Tanzania is expected to increase radiation exposure to its vicinity. This work aims to review the effect of naturally occuring radioactive substances in the villages around Minjingu since last research, 2000. This work will determine background radioactivity levels in soil and background concentration levels of essential elemental composition in soil and to estimate the committed effective dose received by the population in the vicinity of Minjingu mining phosphate. Gamma ray spectrometry and Energy Dispersive X-ray Fluorecence (EDXRF) will be used for sample analysis.
Determination of Prohylactic Activity of HIV-Protease Inhibitors and their Interractions with Antimalarials.
(2013-12-16) Mburu, D. T.; Makumi, J. N.
Malaria is a leading cause of morbidity and mortality in sub-Saharan Africa with children under 5 years and pregnant women at the highest risk. Over years, there has been an enhanced effort all over the world to find an effective drug or a vaccine against the protozoa. However most antimalarial drugs have been countered by increased resistance by parasite to the drugs rendering them ineffective. Among potential targets for new modes of chemotherapy are malarial proteases, which appear to mediate processes within the erythrocytic malarial life cycle, including the rupture and invasion of infected erythrocytes and the degradation of hemoglobin by trophozoites. Aspartic proteases playa key role in the biology of malaria parasites and human immunodeficiency virus type 1 (HIV -1). Most antivirals used in HIV therapy target these proteases that cleave a viral polyprotein precursor into individual mature proteins. Plasmodium falciparum, the most virulent human malaria parasite, expresses a number of aspartic proteases, known as plasmepsins. The convergence in dependence of the two parasites on the aspartic proteases makes them similar targets for chemotherapy. Malaria and AIDS share a wide geographical overlap in occurrence both being more prevalent in sub-Saharan Africa and the interaction of the two diseases results in co-infection which clearly has major public health implication. Given their known dependence on proteases, it appears the protease inhibitors (PI) in the treatment certainly exert a certain degree of antimalarial effect. This has also been demonstrated in in vitro and in vivo with the most potent compound, lopinavir, active against parasites at concentrations well below those achieved by ritonavir-boosted lopinavir therapy. The objective of this study will therefore be to assess the antimalarial activity of protease inhibitors in mice models, and assess if they have protective role when taken before malaria infections and whether their co-use with the malarial drugs has any interactions that would affect their utilization. Three HIV protease inhibitors Ritonavir, Saquinavir mesylate and Nelfinavir mesylate hydrate (Sigma Aldrich) currently available in Kenyan markets will be used. Mice (5 for each group) infected with Plasmodium berghei will be treated with each of the protease inhibitors (PIs). Parasitaemia will be determined every 3 days by microscopy and cure/survival rate over a period of 30 days recorded. Another group will be treated with a combination of ritonavir and conventional antimalarial drug artemether-lumefantrine (coartem) to assess their interaction and another prophylactic assay. The effects of inhibitors on P. bergei morphologytshape and cell integrity) will be assessed by light microscopy of Giemsa-stained smears. Data will be entered in excel spreadsheet and analyzed with student's T-test and ANOVA to determine whether the observed differences between the mean parasitaemia of the treatment groups is significant and testing significance within and between groups respectively. Statistical significance will be considered at P<0.05. Results of this study will generate useful information that can be used by malaria control programs especially in areas where both HIV/AIDS and malaria are endemic hence co-infection is high .
Determination of selected drought resistant grass species that could be used as alternative hosts of chilo parteuus (swinhoe) in Kisumu county, Kenya
(2014-07-31) Oncbangwa, A. Macbani; Kairu, E. W.
The stem borer (Chilo partellus Swinhoe, Lepidoptera: Pyralidae) is an important pest of maize in tropical lowland areas of Africa, seldom found above altitude of 1500 metres above sea level. Yield losses are caused by the borer feeding on plant leaves, grains, tussles and tunneling in stems hence weakening the plant. It is difficult to control C. partellus since both larvae and pupae live in stems. Spraying with insecticides only kills eggs and adults. Other methods used to control C. partellus include biological methods, host plant resistance and cultural practices. Trap plants could also help to control the pest. Trap plants are crops grown to attract insect pests so as to protect target crops from pest attack. This study is aimed at providing an alternative control measure by use of trap plants to control C. partellus. This approach may be used by smallholder farmers in dry areas of Kenya so as to boost their cereal production for subsistence consumption. The field experiments for the study will be conducted at Nyakach District in Kisumu County where ten grass species will be used while controlled green house experiments will be done at Kenya Agricultural Research Institute (KARl), Kisii centre. Green house experiments will help in confirming whether the damages that were observed in the field were due to C. partellus attack. The ten grass species that will be selected for both field and greenhouse experiments include Pennisetum sphacelatum, P. mezianum, P. pedicallum, Hypperhania spp, Hyparrrhenia cymbaria, Panicum maximum, Sporobolus pyramidalis, S. consimilis, Chloris gayana and Braicharia brizantha. These grasses were selected for this study because they can withstand drought, enrich the soil with nutrients by controlling soil erosion and can be used as fodder. The grass species will be planted in ten plots each measuring 2 m x 2 m during the dry period. The plots will be arranged in a randomized complete block design. Each grass species will be replicated three times. Data on number of larvae, entry and exit holes on stems, length of stem tunnels, number of "window" holes on leaves, number of eggs on stems and leaves and "dead hearts" will be collected from five grass stools picked randomly from each plot one month after planting in both field and green house experiments. Subsequent data collection will be done after every two weeks for a period of 6 months. Data on foliar damage will be collected using a scale of 1 to 9. Scale value of one will indicate no damage while that of nine will indicate grass damage. The larvae collected from the field and green house will be put in labeled bottles and taken to the laboratory for identification. The data obtained from the field and green house experiments will be subjected to ANaYA or its non-parametric equivalent and analysed using Statistical Analysis System (SAS) 2010. If there will be a significant difference among the treatments, the means will be separated using the Student-Newman-Keuls (SNK) test at a significance level of p = 0.05. The findings of this work are envisaged to assist farmers and agricultural officers in coming up with an integrated pest management system for managing C. partellus instead of using insecticides.
Determination of some trace elements with known immunological response and curative properties in some selected medicinal plants
(2014) Njenga, Isaac Kariuki
The emergence of drug resistant diseases coupled with the ever-nsmg cost of drugs and difficulties in assessing health care in Kenya has resulted in an upsurge of interest in herbal plants. Many sythentic drugs among them artemesinin used for malaria treatment have been derived from herbal plants.There has been a great emphasis on analysis of organic compounds in the herbal plants over the years.These bioactive compounds are part of the plant matrix which include the trace elements. Some trace elements have known immunological response and curative properties which might explain the efficacy of the herbal plants and thus the significance of this study. This study will be carried out to determine the concentrations of trace elements with known immunological response and healing properties in selected medicinal plants available in Kenya and used for treating various diseases. These plants are Prunus Africana (Hook f.) Kalkman,Urtica doica L., May ten us obscura (A. Rich.) Cuf., May tenus putterlickiodes, Azadiracta indica A. Juss , Mondia whytei (Hook. F.) , Zanthoxylum usambarense, Maerua edulis (Gilg & Gilg-Ben) , Trigonella foenum-graecum L. and Glycyrrhiza glabra . L. The last two are common exotic species.The concentrations of Zinc, Chromium, Vanadium and Selenium will be determined by the use of Atomic Absorption Spectroscopy (AAS) and Energy Dispersive X-ray Fluorescence Spectroscopy (EDXRF). The data will be analysed using SPSS and Ms Excel computer software. Spectral data analysis for EDXRF elemental concentration will be done using QAES, AXIL and S-100 computer software. The information obtained will be used to enhance the indigenous knowledge of the medicinal plants through dissemination to the public and health care providers.
Development and On-Host Evaluation of Controlled-Release Formulations of Optimised Potent Repellents or Blends against Rhipicephalus Appendiculatus
(Kenyatta University, 2014-10-08) Kariuki, Margaret Wangechi
Tick borne diseases are major constraints to livestock productivity and food security in many developing countries. They cause high morbidity and mortality in cattle, and prevent the introduction of highly productive but disease-susceptible breeds of cattle. They are also expensive to control and place a huge economic burden on poor small holder farmers. East Coast Fever (ECF, Theileria parva, Theiler 1904) is one of the most serious of the theileria species. ECF is transmitted primarily by the brown ear tick Rhipicephalus appendiculatus. In Africa, it is estimated that 1.1 million cattle suffer from ECF resulting to losses at US dollars 168 million. In Kenya, about 50-80% of the national cattle population of about 10 million animals is exposed to tick infestations and out of this 1% die of ECF each year. Use of semiochemicals represents a strategy for the control management of the vector which is eco-friendly. On host behavior studies of adult R. appendiculatus shows preference to feed mainly inside and around the ear of their host. Combination of a repellent blend from the anal region and an attractive blend at the ear has been shown to play natural "push" and "pull" roles, respectively, to guide these ticks to the cattle ears. In a preliminary study, application of a crude repellent blend collected from the anal region at the ears has been shown to confuse the ticks, most of which drop off the cattle. Preliminary work showed the presence of forty three compounds in the GC-MS of the anal odour. These compounds include ketones, phenols, amines and alcohols. The major constituents comprised of 4-methylguaiacol, 4-hydroxy-4-methl-2-pentanone, and 3-methyl-2-pentanone among others. Bioassays of blends of these and individual constituents showed varying levels of repellence, with 4-methylguaiacol showing the most repellent effect. A number of analogues of this constituent was tested and 2,4-dimethylphenol was found to be most repellent . The present research will build on these results, undertake further structure-activity studies and evaluate potent compounds individually and in blends in laboratory assays and on cattle. This will be followed by development of a controlled-release formulation of a selected repellent or blend, which can then be evaluated in a push tactic on the host animals. All data will be analyzed using Analysis of Variance (AN OVA) while the mean will be compared by Student -Newrnan-Keuls test at P 20.05.
Dietary Intake, Nutritional Status and Morbidity Patterns of Male Prisoners living WITH HIV at Selected Prisons in Kenya
(2013-12-23) Kavithe, R.K.; Mbithe, D.; Maoga, W. N.
People living with HIV and AIDS face increased challenges in maintammg proper nutrition. HIV negatively affects almost all body systems, which results in recurrent opportunistic infections, weight loss, distribution of weight changes, and death. Dietary intake and consequently nutrition status impacts on HIV either negatively or positively. Within prison settings, barriers exist that limit the ability of prisoners to improve and maintain their health. Male inmates living with HIV are well recognized as vulnerable and socially excluded population, whose acquiring of adequate treatment is greatly affected by poor nutritional status among other factors. The purpose of the study will be to assess the food consumption patterns, nutritional and health status of male prisoners living with HIV at selected GK prisons in Kenya as well as determine the factors that affect the same. The study will use a cross sectional analytical survey with a sample size of 135 male inmates. The study will be carried out on HIV positive male inmates at the 4 selected GK prisons, both on remand and convicted. The subjects will include both those on care (Cotrimoxazole and multivitamins) and on treatment (ARVs) and should have been within the prison walls for the last 3 months. Purposive sampling will be used to select the study population (HIV positive prisoners) and simple random sampling to select the subjects among the HIV positive male inmates in the 4 prisons. The study is aimed at influencing the prison menu to be in line with the nutrition and HIV guidelines in order to improve nutrition care for HIV positive prisoners. An observation checklist will be used to check the food eaten, method of cooking used, amounts served and conditions in which the food is served. A structured questionnaire and FGDs will also be used to collect data. Anthropometric measurements will also be taken on all the subjects. Anthropometric data will be analyzed by use of Epi Info while nutrition data will be analyzed by use of Nutrisurvey. This data will further be analyzed by use of Statistical . Package for Social Sciences (SPSS Version 17) software. Association between health and nutrition status will be analyzed by use of regression analysis. Pearson's Product Moment correlation (r) will be used to analyze continuous data where P -Value <0.05 will be considered significant. Descriptive statistics will be used to describe and summarize data on HIV positive male inmates' socio economic, demographic characteristics and health factors. Data presentation will be in a form of descriptive statistics, that is frequency tables, cross tabulations, pie charts and bar graphs and appropriate inferential statistics will also be presented.

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