Publications

Found 7472 results

Sort by: [ Author  (Asc)] Title Type Year
Filters: First Letter Of Last Name is O  [Clear All Filters]
A B C D E F G H I J K L M N [O] P Q R S T U V W X Y Z   [Show ALL]
O
Obadiah N'ang'a, George N, W K, Abungu NO. An experimental Prototype for Low Head Small Hydro Power Generation Using Hydram.. Jomo Kenyatta University of Agriculture and Technology(JKUAT): JKUAT; 2012. Abstractjkuat_conference_paper.pdf

The global rise in energy demand has resulted to the over exploitation of both renewable and non renewable energy sources. Most feasible hydroelectric power (HEP) plants sites have been exploited and the current focus is on harnessing energy from small HEP plants which have low head and flow velocity rendering them unsuitable for HEP generation. Previous research work focused on improving the turbine shape and efficiency; designing better water intake, improving the generator and development of turbines suitable for low heads. The main aim of this research was to optimize the power generated by low head small hydro plants through the use of hydraulic ram pump (hydram) to boost the water pressure before it impinges on the turbine. In the current work, a smallHEP prototype system was designed fabricated and test runs conducted. The prototype comprised of; a low head water reservoir, a hydraulic ram pump which was used to increase the head of the water emanating from a low head source, a high head reservoir mounted at a the most optimal height based on the hydram flow rate and pressure considerations and a double cup pelton wheel turbine suitably designed to extract power from the water jet. A drive pipe was used to connect thehydram pump to the low head reservoir while the delivery pipe connected the pump to the high head reservoir. Water from the high head reservoir was used to turn the pelton turbine which was coupled to a generator. The flow rate in the drive pipe and the delivery pipe as well as the pressurein the hydram were optimized by adjusting the waste valve stroke length. It was observed that the hydram was able to pump water to a higher head which then increased the power produced by the turbine.

Obae R. Characteristics of dropouts among upper primary pupils. Beau Bassin, Mauritius: VDM Publishing House Ltd.; 2011.
OBAE MOSOTI ROSE NYABOKE. " HEADTEACHERS AND TEACHERS PERCEPTIONS TOWARDS THE CHARACTERISTICS OF DROPOUTS AMONG PUPILS IN UPPER PRIMARY IN NAIROBI PROVINCE.". In: Maseno Journal of Education, Art and Science Vol. No.1. Opuscula Mathematica,; 2013.thesis_abstract.doc
Obaga IM, Omido DK, Garashi HM, Odera O, Ogutu PM. "Analysis of retail marketing strategies on Organizational competitiveness." International Journal of Management & Information Technology. 2013;3(2). Abstractanalysis_of_retail_marketing_strategies_on_organizational_competitiveness.pdf

The purpose of this study was to analyze retail marketing strategies on organizational competitiveness. The study attempted to examine the strategies that have been applied and adopted by the retail companies elsewhere in attempt to understand how retailing functions. A descriptive research design was employed in this study. The population was marketing executives in the selected bottling companies in Kenya. Primary data was collected using closed questionnaire. The data collected was organized and presented using descriptive statistics. Correlation analysis was also utilized for data analysis. Findings indicate that the most pursued retail marketing strategies were; marketing segmentation, product strategies, distribution, pricing, marketing relationship and promotions. The findings also suggest that bottling companies rely on combination of strategies as different market segments respond differently hence need for product-specific marketing strategy.
Keywords: Retail marketing strategies, organizational competitiveness, Kenya

Obala LM, Kimani MW. "Land-use Conflicts and Urban Land Management in Kenya.". 2002. AbstractWebsite

Protected areas throughout the world are key for conserving biodiversity, and land use is key for providing food, fiber, and other ecosystem services essential for human sustenance. As land use change isolates protected areas from their surrounding landscapes, the challenge is to identify management opportunities that maintain ecological function while minimizing restrictions on human land use. Building on the case studies in this Invited Feature and on ecological principles, we identify opportunities for regional land management that maintain both ecological function in protected areas and human land use options, including preserving crucial habitats and migration corridors, and reducing dependence of local human populations on protected area resources. Identification of appropriate and effective management opportunities depends on clear definitions of: (1) the biodiversity attributes of concern; (2) landscape connections to delineate particular locations with strong ecological interactions between the protected area and its surrounding landscape; and (3) socioeconomic dynamics that determine current and future use of land resources in and around the protected area.

Obala LM, Olima WHA. The effect of existing land tenure systems on urban land development: A case study of Kenya's secondary towns, with emphasis on Kisumu.; 1988. Abstract

The Kenya Government has over a number of years pursued policies geared towards the promotion of secondary towns. Included in this strategy is the achievement of an orderly and coordinated urban land development. However, experience from these towns indicates that, planned land development has encountered a lot of bottlenecks particularly in relation to the institution of private ownership of land. This paper traces the land tenure systems that have existed in the Kenya’s secondary towns. In general, the paper examines the effects of land tenure forms on the provision of housing and the related infrastructure. The effects of existing land tenure identified include influence on housing development, influence on planned land development, cloudiness of titles, hoarding and speculation, insecurity, inflexibility and inequity. The paper concludes by making suggestions based on the observed bottlenecks that should be considered to encourage and promote systematic urban land development in secondary towns.

Obala LM, Olima WHA. The effect of existing land tenure systems on urban land development: A case study of Kenya's secondary towns, with emphasis on Kisumu.; 1988. Abstract

The Kenya Government has over a number of years pursued policies geared towards the promotion of secondary towns. Included in this strategy is the achievement of an orderly and coordinated urban land development. However, experience from these towns indicates that, planned land development has encountered a lot of bottlenecks particularly in relation to the institution of private ownership of land. This paper traces the land tenure systems that have existed in the Kenya’s secondary towns. In general, the paper examines the effects of land tenure forms on the provision of housing and the related infrastructure. The effects of existing land tenure identified include influence on housing development, influence on planned land development, cloudiness of titles, hoarding and speculation, insecurity, inflexibility and inequity. The paper concludes by making suggestions based on the observed bottlenecks that should be considered to encourage and promote systematic urban land development in secondary towns.

Obamba MO, Kimbwarata J, RIECHI ANDREWR. "Development Impacts of International Partnerships.". In: Internationalisation of African Higher Education. SensePublishers; 2013:. Abstract
n/a
Obanda V, Maingi N, Muchemi G, Ng’ang’a CJ, Angelone S, Archie EA. "Infection dynamics of gastrointestinal helminths in sympatric non-human primates, livestock and wild ruminants in Kenya." PLoS ONE . 2019;14(6).
obanda BA, Cook A, Fevre E, Wang S, Bebora L, Mwituria JM, Ng'etich R, Okoth W, Nafula C, Ogara W, Thaiyah AG, Kariuki S, Gabreyes WA. "Nasal carriage of Staphylococcus aureus in abattoir workers and livestock from western Kenya.". In: ICOPHAI. Thailand; 2015.
Obara I, Ulrike S, Musoke T, Spooner PR, Jabbar A, Odongo D, Kemp S, Silva JC, Bishop RP. "Molecular evolution of a central region containing B cell epitopes in the gene encoding the p67 sporozoite antigen within a field population of Theileria parva." Parasitol Res. 2015;114(5):1729-37. Abstract

Protective immunity induced by the infective sporozoite stage of Theileria parva indicates a potential role for antibodies directed against conserved serologically reactive regions of the major sporozoite surface antigen p67 in vaccination to control the parasite. We have examined the allelic variation and determined the extent of B cell epitope polymorphism of the gene encoding p67 among field isolates originating from cattle exposed to infected ticks in the Marula area of the rift valley in central Kenya where the African cape buffalo (Syncerus caffer) and cattle co-graze. In the first of two closely juxtaposed epitope sequences in the central region of the p67 protein, an in-frame deletion of a seven-amino acid segment results in a truncation that was observed in parasites derived from cattle that co-grazed with buffalo. In contrast, the variation in the second epitope was primarily due to nonsynonymous substitutions, resulting in relatively low overall amino acid conservation in this segment of the protein. We also observed polymorphism in the region of the protein adjacent to the two defined epitopes, but this was not sufficient to provide statistically significant evidence for positive selection. The data indicates that B cell epitopes previously identified within the p67 gene are polymorphic within the Marula field isolates. Given the complete sequence identity of the p67 gene in all previously characterized T. parva isolates that are transmissible between cattle by ticks, the diversity observed in p67 from the Marula isolates in combination with the clinical reaction of the infected cattle is consistent with them originating from ticks that had acquired T. parva from buffalo.

Obara I, Githaka N, Nijhof A, Krücken J, Nanteza A, Odongo D, Lubembe D, Atimnedi P, Mijele D, Njeri A, Mwaura S, Owido G, Ahmed J, Clausen PH, Bishop RP. "The Rhipicephalus appendiculatus tick vector of Theileria parva is absent from cape buffalo (Syncerus caffer) populations and associated ecosystems in northern Uganda." Parasitol Res. 2020;119(7):2363-2367. Abstract

Rhipicephalus appendiculatus is the major tick vector of Theileria parva, an apicomplexan protozoan parasite that causes the most economically important and lethal disease of cattle in East and central Africa. The African cape buffalo (Syncerus caffer) is the major wildlife host of T. parva from southern Uganda and Kenya to southern Africa. We show herein that R. appendiculatus appears to be absent from the two largest national parks in northern Uganda. Syncerus caffer is common in both of these national parks, specifically Murchison falls (MFNP) and Kidepo Valley (KVNP). We re-confirmed the previously reported absence of T. parva in buffalo sampled in the two northern parks based on RLB data using a nested PCR based on the T. parva p104 gene. By contrast, T. parva-infected R. appendiculatus ticks and parasite-infected buffalo were present in Lake Mburo (LMNP) in South central Uganda. This suggests that the distribution of R. appendiculatus, which is predicted to include the higher rainfall regions of northern Uganda, may be limited by additional, as yet unknown factors.

Obare S, Ayienga E. "Performance Evaluation and Optimization of IP Lookup Algorithm.". In: UNESCO-HP Brain Gain Workshop. Nairobi, Kenya; 2012.
Obare F, Otieno AAT, Magadi M. "Gender role attitudes, Self Efficacy and Reproductive Health Communication among female adolescents in South Nyanza, Kenya." African Population studies. 2006; 21(1):37-54. AbstractWebsite

The antihypertensive effect of the fixed combination of timolol, a beta-blocking agent, hydrochlorothiazide, a thiazide diuretic, and amiloride, a potassium sparing agent, was compared against that of methyldopa in an open study lasting 16 weeks in 32 ambulatory African patients with previously untreated diastolic blood pressure of 95-120 mm Hg. A significant fall in mean diastolic and systolic blood pressure was achieved in both groups up to 8 weeks of treatment and was sustained in the timolol-hydrochlorothiazide-amiloride group during the entire follow-up. In the methyldopa group, mean diastolic and systolic blood pressure rose during follow-up. At 16 weeks the fall in mean diastolic and systolic blood pressure was significantly greater in the timolol-hydrochlorothiazide-amiloride treated patients than in the methyldopa group. Adverse reactions were more frequent and severe in the methyldopa group than in timolol-hydrochlorothiazide-amiloride treated patients. It is concluded that the fixed drug combination of timolol-hydrochlorothiazide-amiloride (Moducren) is effective in controlling mild to moderate hypertension in Africans and is better tolerated than methyldopa in these patients. It is further noted that hypertensive patients can be treated with a combination tablet once a day. This is of crucial significance as it would promote better compliance and, hence, minimize the sequelae of poorly controlled hypertension.

Obel OA, Camm AJ. "The use of drugs for cardioversion of recent onset atrial fibrillation and flutter. Focus on ibutilide.". 1998. Abstract

Atrial fibrillation (AF) is the most common sustained arrhythmia, particularly in the elderly population. It is well recognised that AF is a major cause of stroke, even in the absence of underlying heart disease. Although AF and atrial flutter share many causes and may be seen in the same patient, there are differences between these arrhythmias: atrial flutter is less common, and the risk of stroke associated with it is less than that with AF. In addition to stroke, both AF and atrial flutter may cause cardiomyopathy, which may be fully reversible with effective treatment of the arrhythmia. Both AF and atrial flutter can result in severe symptoms and may precipitate heart failure, ischaemia and syncope. Recent research indicates that AF is a self-perpetuating arrhythmia, and that the longer it is left untreated the less likely it is that effective cardioversion will be possible. Drugs are an attractive option for the cardioversion of AF and atrial flutter because their use does not require anaesthesia. Antiarrhythmic drugs in class III of the Vaughan-Williams classification are effective in the treatment of AF, but they have adverse effects; several new 'pure' class III agents are under development. The first of these to be made available is ibutilide, a methanesulphonamide derivative. Initial results are encouraging, particularly for atrial flutter. However, the drug has the potential for proarrhythmic effects and physicians who use it will need to be aware of these.

OBEL DRGORCHRISTOPHER. "Gor, C.O., and Riesenberg, L. (September, 1989). .". In: PhD Thesis , University of Nairobi. Opuscula Mathematica,; 1989.
Obel AO. "Epidemiology and diabetes mellitus in referral hospital in a tropical developing country. ." Tohoku Journal of Experimental Medicine. 1983;(14):207-10.
Obel AO. "Cushing ’ s Syndrome in Africans." East African Medical Journal. 1980;(57):495-99.
Obel AO. "Pharmacology of beta adrenoreceptor blocking agents." East African Medical Journal.. 1993;70(7):401.
Obel AO, J N, W G. "Antipyrine half - life in hyperthyroidism." East African Medical Journa l . 1981;(58):258-62.
Obel AO. "A comparison of timolol plus hydrochlorothiazide plus amiloride and methyldopa in essential hypertension in black Africans." ropical and Geographical Medicine. 1983;(35):285-91. AbstractWebsite

The antihypertensive effect of the fixed combination of timolol, a beta-blocking agent, hydrochlorothiazide, a thiazide diuretic, and amiloride, a potassium sparing agent, was compared against that of methyldopa in an open study lasting 16 weeks in 32 ambulatory African patients with previously untreated diastolic blood pressure of 95-120 mm Hg. A significant fall in mean diastolic and systolic blood pressure was achieved in both groups up to 8 weeks of treatment and was sustained in the timolol-hydrochlorothiazide-amiloride group during the entire follow-up. In the methyldopa group, mean diastolic and systolic blood pressure rose during follow-up. At 16 weeks the fall in mean diastolic and systolic blood pressure was significantly greater in the timolol-hydrochlorothiazide-amiloride treated patients than in the methyldopa group. Adverse reactions were more frequent and severe in the methyldopa group than in timolol-hydrochlorothiazide-amiloride treated patients. It is concluded that the fixed drug combination of timolol-hydrochlorothiazide-amiloride (Moducren) is effective in controlling mild to moderate hypertension in Africans and is better tolerated than methyldopa in these patients. It is further noted that hypertensive patients can be treated with a combination tablet once a day. This is of crucial significance as it would promote better compliance and, hence, minimize the sequelae of poorly controlled hypertension.

Obel AO, W.M KT-, Ellison R.H MM. "Dietary sodium/potassium ratios in salt substitute and its putative significance in essential hypertension." East African Medical Journal. 1985;( 62):507-514.
Obel AO, EG M. "Double - blind placebo controlled trial of glafeinine in acute pain." East African Medical Journal. 1981;(58):226-30.
Obel OA, d'Avila A, Neuzil P, Saad EB, Ruskin JN, Reddy VY. "Ablation of left ventricular epicardial outflow tract tachycardia from the distal great cardiac vein.". 2006. AbstractWebsite

The purpose of this study was to examine the feasibility and safety of ablation of idiopathic outflow tract ventricular tachycardia (OTVT) from the distal ramifications of the coronary sinus (CS).
A significant minority of patients presenting with idiopathic OTVT have an epicardial focus, the standard approach to which involves ablation from within one of the aortic valve cusps (AVCs). We describe the successful ablation of idiopathic epicardial OTVT from within the CS in the distal great cardiac vein (GCV).

Ablation from the distal GCV was performed in 5 patients with idiopathic OTVT who had unfavorable mapping, in some cases unsuccessful ablation from various endocardial and epicardial sites including the AVCs, and in 1 patient via the direct epicardial approach. An electroanatomic mapping system (Carto) was used in 3 patients, and conventional mapping was performed in 2 patients, and in 3 patients cryothermal ablation was performed.
In all patients, the first ablation lesion in the GCV successfully eliminated the arrhythmia. All patients have remained free of VT after a mean follow-up of 24 (7 to 44) months. There were no immediate or long-term complications.
Idiopathic epicardial OTVT can be successfully ablated from the distal GCV, and should be seen as an alternative to ablation from the aortic valve cusps.

OBEL DRGORCHRISTOPHER. "Gor, C.O. (May, 1988). .". In: Masters. Opuscula Mathematica,; 1988.
Obel AO. "Anti - mycotic agents and their relevance to HIV – infected patients." Medicine in Africa. 1993;(2):6-8.
Obel AO. "Pharmacokinetics in medicine.". 1982.
Obel AO, L G, J W. "Comparison of slow - release frusemide (Lasic Retard) and bendrofluazide in the trea tment of moderate hypertension in Kenya Negroes." Clinical Trial Journal. 1984;(21):443-50. AbstractWebsite

The relative efficacy and the risk of producing biochemical disturbances by bendrofluazide, 10 mg once daily and slow-release frusemide (Lasix Retard) 60 mg once daily, during treatment of moderate hypertension in Kenyan negroes were compared in a double-blind randomized control study. Fifty newly diagnosed hypertensive patients entered the study which lasted for 36 wk. There were 7 drop-outs at the end of the trial. Both slow-release frusemide and bendrofluazide significantly decreased both supine and standing diastolic pressures and standing systolic pressure (P < 0.05). Bendrofluazide also showed a significant effect on supine systolic pressure (P < 0.01), which was greater than that of slow-release frusemide. Biochemical disturbances were more pronounced in patients receiving bendrofluazide than in those on slow-release frusemide. Bendrofluazide treatment resulted in significant hyperuricemia (P < 0.02), hypokalemia (P < 0.01) and a rise in blood glucose which was not statistically significant (t [test of significance] = 0.26). Slow-release frusemide produced no significant alterations in blood uric acid, K and blood glucose. Both treatment modalities produced no significant change in other biochemical and hematological indices. Compared with slow-release frusemide, bendrofluazide produced potentially serious adverse biochemical changes. The drugs were equally effective in controlling moderate hypertension although the hypotensive effect on systolic blood pressure was more pronounced with bendrofluazide.

Obel AO. "Antipyrine and progranolol disposition in malnutrition." East African Medical Journal. 1978;(55):20-24.
Obel OA, Camm AJ. "Supraventricular tachycardia. ECG diagnosis and anatomy.". 1997. Abstract

This paper reviews the anatomical substrates responsible for the induction and maintenance of supraventricular tachycardia and discusses the ECG findings associated with these tachycardias. The normal anatomy of the supraventricular conducting system, particularly within the atria, is complex with conduction proceeding along preferential pathway, which are in turn determined in part by the anisotropic properties of the atrial myocardium. There appear to be at least dual inputs to the atrioventricular node, a posteriorly situated slow pathway and an anterior fast pathway. It is sometimes possible to relate ECG findings directly to anatomical substrates; for example, in some cases of atrial tachycardia the site of the atrial focus (left or right, superior or inferior) can be determined by the polarity of the P wave. The anatomical substrates responsible for intra-atrial re-entry, atrial flutter and atrial fibrillation relate to anatomical barriers to impulse propagation and areas of slow conduction. In atrial flutter the crista terminalis, Eustachian valve, inferior vena cava, coronary sinus os, and tricuspid annulus have been identified as anatomical barriers to conduction around which a macro re-entrant circuit within the right atrium may conduct, usually in a counter-clockwise direction. Clockwise direction of conduction, and other mechanisms of tachycardia, occur in some of the less typical forms of atrial fluter. Atrial fibrillation is caused by multiple wavelets which randomly conduct through the atrial myocardium and are responsible for the irregular 'fibrillation waves' on the ECG. Supraventricular tachycardia presents as a narrow complex tachycardia unless pre-existing or rate-related bundle branch block is present. Less common causes for a broad complex tachycardia occurring in supraventricular tachycardia include an accessory atrioventricular or atriofascicular pathway conducting antegradely during tachycardia, or accessory pathway participation as a bystander during supraventricular tachycardia. ECG features which can help to distinguish between atrioventricular nodal re-entrant tachycardia and atrioventricular re-entrant tachycardia include: (1) the presence of a delta wave during sinus rhythm which is highly suggestive of atrioventricular re-entrant tachycardia as the mechanism of supraventricular tachycardia; (2) the finding of a pseudo s (lead II) or pseudo r' (lead V1) during tachycardia in atrioventricular nodal re-entrant tachycardia; (3) lengthening of the tachycardia cycle length in cases of atrioventricular re-entrant tachycardia when bundle branch block occurs ipsilateral to the accessory pathway and (4) the finding of QRS alternans during tachycardia which is suggestive of atrioventricular re-entrant tachycardia. "Long RP' tachycardia may be caused by an atrial tachycardia due to an inferiorly situated area of abnormal automaticity, atypical atrioventricular nodal re-entrant tachycardia with slow retrograde conduction, or atrioventricular re-entrant tachycardia with an accessory pathway conducting slowly from ventricle to atrium during tachycardia.

Obel AO. "Body mass index in Non - Insulin Dependent Diabetes in K enya." Tropical and Geographical Medicine . 1988;40(2):93-96.
Obel AO. "Placebo - controlled trial of potassium supplements in black patients with mild essential hypertension." ournal of Cardiovascular Pharmacology. 1989;14(2): 294-296.
OBEL DRGORCHRISTOPHER. "Gor, C.O., and Riesenberg, L. (July, 1987). .". In: Masters. Opuscula Mathematica,; 1987.
Obel OA, Camm AJ. "Accessory pathway reciprocating tachycardia.". 1998. AbstractWebsite

Patients who have an accessory pathway (AP) of atrioventricular (AV) conduction may develop circus movement tachycardia otherwise known as atrioventricular re-entrant tachycardia (AVRT). Orthodromic AVRT is the most common form. It occurs as a result of antegrade conduction through the normal AV conduction system and retrograde conduction to the atria via the AP. Less commonly, conduction occurs in the opposite direction resulting in antidromic AVRT. Tachycardia may also involve multiple APs which may provide both antegrade and retrograde conduction and may alternate antegradely or retrogradely. Tachycardia may occur in which the AP simply acts as a bystander, and does not participate in the tachycardia mechanism. When atrial fibrillation is conducted to the ventricles via and AP, the resultant ventricular rate may be extremely rapid, placing the patient at risk of developing ventricular fibrillation and cardiac arrest. This paper reviews the anatomical and physiological substrates involved in the pathogenesis of AVRT. The acute and long-term management of patients who suffer from these arrhythmias will then be discussed. The normal AV annulus is composed exclusively of electrically inert fibrous tissue. The AV node and His bundle normally act as the sole route of electrical conduction. Accessory pathways occur at all points along the AV ring, and usually occur as isolated abnormalities, although a proportion of patients have associated congenital abnormalities. This is particularly true of right-sided APs. Most APs exhibit non-decremental conduction properties, and conduct faster than normal AV conduction tissue. In many patients with APs the surface ECG reveals clear evidence of pre-excitation, and a good idea of pathway localization is possible using one or more of several algorithms which have been developed. Patients with latent pre-excitation, intermittent pre-excitation, and patients with concealed APs have not evidence of pre-excitation on a proportion or all of Their surface ECGs. Patients present with a history of paroxysmal palpitations, often with associated symptoms such as chest discomfort Syncope is a rare presenting symptom. Unless bundle branch block is present, patients with orthodromic AVRT exhibit a narrow complex tachycardia on the surface ECG. Patients with pre-excited tachycardia including antidromic AVRT, and other forms of SVT in which the AP conducts to the ventricles as a bystander but does not participate in the tachycardias mechanism, present as broad complex tachycardias on the surface ECG which may be difficult to distinguish from ventricular tachycardia. Adenosine is increasingly used for this purpose since it is highly efficacious and has an extremely short half-life. Adenosine is also very useful in the diagnosis of broad-complex tachycardia, and in unmasking latent pre-excitation during sinus rhythm. Electrophysiology study in these patients is frequently performed at the same time as an attempt at catheter ablation; it aims to diagnose, localize and determine the functional characteristics of an AP, and to characterize the role of the pathway in tachycardia. AVRT can be reliably terminated by effective AV nodal blockade. Drug therapy for the prevention of AVRT is useful for temporary control whilst awaiting more definitive measures and in certain cases as long-term management. No class of drug stands out as 'therapy of choice', and physician preference, pro-arrhythmic effects and associated conditions need to be taken into account such that an individual choice can be made in each patient. The management of patients with AVRT has been revolutionized in recent years with the advent of catheter-based techniques for their cure. Whilst this method of treatment is highly effective and has low complication rates, pathways in particular locations such as the septal region remain challenging.

Ober-Oluoch JA, Kemoli A, Masiga, Dimba E. "Dental Caries and Periodontal health of Children with Cerebral Palsy.". 2011;2(1).
OBIERO DRSAMUELV. "Rural-Urban Linkages in Regional Development. A paper presented at 6th Africa Training Course on Local and Regional Development and Management, Nairobi, Kenya (2000). UNCRD.". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 2000. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
Obiero A. Automation of library services in Academic libraries. NAIROBI: TECHNICAL UNIVERSITY; 2008.
OBIERO DRSAMUELV. "Role of Non-Motorized Transport Services in Nairobi: A paper to the Velocity Conference, Nottingham, U.K. September 1993.". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 1993. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
Obiero JPO, Gumbe LO, Omuto CT, Hassan MA, Agullo JO. "Development of Pedotransfer functions for saturated hydraulic conductivity." Open Journal of Modern Hydrology. In Press.
Obiero K, Lawrence T, Ives J, Smith S, Njaya F, Kayanda R, Waidbacher H, Olago D, Miriti E, Hecky RE. "Advancing Africa’s great lakes research and academic potential: Answering the call for harmonized, long-term, collaborative networks and partnerships." Journal of Great Lakes Research. 2020. Abstractdio.org

Abstract
The African Great Lakes (AGL) have rich fisheries and are renowned “biodiversity hotspots”. Consequently the AGLand the ecosystem services they provide, underpin the welfare and livelihoods of over 50 million people across 10 countries. Despite the recognized importance of the AGL, these vital ecosystems and their livelihood support systems are threatened by numerous anthropogenic stressors at local, regional, and global scales. Past and continued efforts to address critical challenges on these lakes are often short-term, parochial, disparate, and uncoordinated resulting in a lack of comprehensive and comparable scientific data and inadequate resources to influence evidence-based policy. Over the past two decades, several international workshops, conferences and scientific publications have identified the need for collaboration, knowledge sharing, and harmonization of research and management as key elements to enhance conservation efforts in the AGL. In this commentary, we introduce the African Center for Aquatic Research and Education (ACARE), which aims to strengthen research and provide the scientific evidence needed to make informed decisions related to sustainable fisheries and aquatic resource management in the AGL. To do this, ACARE will administer a highly collaborative network of experts with three long-term goals: (1) strengthen global and regional research partnerships; (2) establish transboundary and inter-jurisdictional lake advisory groups; and (3) build capacity of freshwater scientists through experiential education and public engagement.

Keywords
African Great Lakes Collaborative networks Transboundary lake advisory groups, educationResearch partnerships

OBIERO DRSAMUELV. "Mobility Plan for Eldoret Town: SSATP, World Bank, January 1997.". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 1997. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
Obiero, J.P.O; Thine MCO; DO. "Rainwater Harvesting for Crop Production in Semi-arid Areas.". 2003.
Obiero L, Abdi A. "An Assessment of the Performance of the Social Protection Program for the Elderly Persons." The International Journal of Humanities & Social Studies. 2018;6(3):220-226.
Obiero JPO, Gumbe LO, Omuto CT, Hassan MA, Agullo JO. "Development of Pedotransfer functions for saturated hydraulic conductivity." Open Journal of Modern Hydrology,. 2013;3:154-164.Website
OBIERO DRSAMUELV. "Stakeholders in the Limelight: Principles of Actor-Centred Resources Management. Eastern and Southern Africa. Geographical Journal Vol. 8. Sept. 1998.". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 1998. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
Obiero G, Martha Smit,. SHTL. "Bioconversion of linear alkanes to dicarboxylic acids using genetically engineered yeast strains.". In: Bio-08 conference.; 2008.
Obiero JA, Waititu KK, Mulei I, Omar FI, Jaoko W, Mwethera PG. "Baboon vaginal microbial flora." J. Med. Primatol.. 2016;45(3):147-55. Abstractbaboon_vaginal_microbial_flora.pdfPUBMED

Knowledge of the composition of vaginal microbial ecosystem is essential for understanding the etiology, prevention, and treatment of vaginal diseases. A baboon model has been used to provide detailed understanding of reproductive physiology and immunology applicable to women. However, little is known about the composition of its vaginal microbial ecosystem.

Obiero JPO, Marenya MO, Nkuna TR. "Hydrologic response modelling in Lutanandwa river catchment, Limpopo, South Africa, using Soil Water Assessment Tool (SWAT) model." Journal of Engineering in Agriculture and the Environment (JEAE). 2019;Volume 5.(No1. 2019):1-13.
OBIERO DRSAMUELV. "Identification Process as a Factor in Project Implementation: Case studies from Kenya.". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 1988. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
OBIERO DRSAMUELV. "Planning for Non-Motorized Transport as a Sustainable Transport System in Nairobi: A paper presented at the International Conference on Re-Appraising the Urban Planning Process as an Instrument of Sustainable Urban Development and Management, UNCHS (Habit.". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 1994. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
Obiero, J.P.O; Thine MCO; DO. "Rainwater Harvesting for Crop Production in Semi-arid Areas.". 2003.
Obiero JPO, Hassan. MA. Determining the effect of land use change on streamflow using soil water assessment tool (SWAT) Model. Pula/Sardinia/Italy: CRS4 Research Centre, Italy; 2015.
OBIERO DRSAMUELV. "Rural Planning in Regional Development. A paper presented at the Fourth Africa Training Course on Local and Regional Development Planning and Management, Nairobi, Kenya (1998), United Nations Centre for Regional Development (UNCRD).". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 1998. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
Obiero, A. KOJM & UA. "Strategies used in maintaining students’ discipline in Public secondary schools in Nairobi County, Kenya, ." , International journal of social science and economic research. 2018;3(11).
Obiero JPO. Pedotransfer Functions For Saturated Hydraulic Conductivity For Surface Runoff Modeling .; 2013. Abstract

The study involved development of pedotransfer functions (PTFs) for determining saturated hydraulic conductivity (Ks) used in surface flow prediction. This preceded evaluation of existing PTFs for Ks in flow simulation. The pedotransfer functions were developed to predict parameters used in the determination of Ks using selected basic soil properties. The Soil Water Assessment Tool (SWAT) model was used in flow prediction in the Naro Moru river catchment of the Ewaso Ng’iro river basin, Kenya. The developed pedotransfer functions were then used in the simulation of surface runoff on the catchment and their performance in surface flow prediction compared with that of existing pedotransfer functions. Initial model runs during flow simulation yielded poor daily flow simulations compared to monthly simulations. This was attributed to differences in the timing of peak discharges for the observed and simulated hydrographs. The model was calibrated for a three year period followed by a three year validation period based on monthly flows. Calibration results yielded acceptable, but modest agreement between observed and simulated monthly stream flows. The modest model performance was associated with input data deficiencies and model limitations. The results indicated that the model could be adapted to the local conditions. Manual flow calibration was performed to improve simulation results initially based on average annual conditions followed by monthly calibration. There was significant improvement in the model performance based on monthly flow simulations. The model simulation of surface flow registered better performance compared to base flow and total flow indicating the model to be a better simulator of surface flow than baseflow. Observed and predicted surface runoff was compared to evaluate performance of existing PTFs. Model performance was similar for the existing PTFs selected. There was diversity v in performance of PTFs when used for surface runoff prediction. It was felt there is the need for continued development of PTFs for predicting Ks. The developed PTFs were evaluated for accuracy and reliability. The PTFs developed for saturated soil moisture content (θs) produced better performance in reliability compared to the remaining parameters in the van Genutchen moisture retention equation. The developed pedotransfer functions were then used in predicting Ks for surface flow simulation. The model performance in surface runoff simulation using developed PTFs was found acceptable. The study provides insight in developing equations for predicting Ks from basic soil properties being an input parameter in hydrological models. Hydrologic modeling plays a significant role in enabling policy makers, watershed planners and managers make appropriate decisions consistent with sustainable management of watershed resources.

OBIERO DRSAMUELV. "Feasibility Studies in Transport. Input in the Transportation Policy Framework for Ministry of Transport, Kenya, April 2004.". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 2004. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
Obiero GO. "Evaluation of Yarrowia lipolytica as a host for cytochrome P450 monooxygenase expression." University of the Free State. 2006. Abstract

Biohydroxylation reactions are catalyzed by various types of hydroxylating enzymes (Ayala and Torres, 2004) which include dioxygenases, lipooxygenases as well as CYP450 monooxygenases. These particular hydroxylation reactions have several advantages over chemical synthesis. Several microorganisms including yeasts have the ability to hydroxylate various substrates. The exploitation of microbial hydroxylations for the production of industrially useful products such as pharmaceuticals is a more recent development (Holland et al., 2000). Yeasts from the genera Schizosaccharomyces, Pichia, Saccharomyces and Yarrowia have all been used to express foreign CYP450 genes (Mukarami et al., 1990; Nthangeni et al., 2004) since they offer an advantage especially when a eukaryotic environment is required for the functional expression of the heterologous gene (Blanquet et al., 2003). A recent evaluation of several yeasts revealed that Y. lipolytica is, a highly attractive alternative host for secretion and expression cloning (Muller et al., 1998; Juretzek et al., 2001). However, a literature search on successful expression of CYP450s in Y. lipolytica yielded only six cases. Three of these were done in our laboratory. In most of the reported cases, the recombinant CYP450 activities were never evaluated in terms of whole cell biotransformations. It was therefore the aim of this study to evaluate Y. lipolytica as a recombinant whole-cell biocatalyst for hydroxylation reactions by using available Y. lipolytica strains overexpressing different CYP450s which were (i) CYP1A1 coding for polyaromatic hydrocarbon hydroxylase (ii) CYP53B1 coding for benzoate.

Obiero LM, Abong' GO, W OM, OMAYIO DUKEG, G OE, Villacampa M. "Current practices concerning the environmental management systems among horticultural processing MSMES in Kenya." East African Journal of Science, Technology and Innovation,. 2021;2(special Issue):1-16.current_practices_of_msmes.pdf
OBIERO DRSAMUELV. "Para-Professionl Training For Human Settlements in Kenya. Which was incorporated in the Kenya National Paper entitled: A Systematic and Comprehensive Approach to Training for Human Settlements and a Systematic and Comprehensive Approach to Information for.". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 1988. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
OBIERO DRSAMUELV. "The Study of the Development of Multimodal Transport Services in Kenya. United Nations Development Programme, Nairobi, November 1993.". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 1993. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
Obiero JPO, Onyando JO. "Climate.". In: KENYA : A NATURAL OUTLOOK GEO ENVIRONMENTAL RESOURCES AND HAZARDS. Netherlands: ELSEVIER; 2013.
OBIERO DRSAMUELV. "Urbanization as a Component of Regional Development. A paper presented atFourth Africa Training course on Local and Regional Development and Management, Nairobi, Kenya (1998), UNCRD.". In: Vaccine. 2008 May 23;26(22):2788-95. Epub 2008 Mar 31. IBIMA Publishing; 1998. Abstract
The safety and immunogenicity of plasmid pTHr DNA, modified vaccinia virus Ankara (MVA) human immunodeficiency virus type 1 (HIV-1) vaccine candidates were evaluated in four Phase I clinical trials in Kenya and Uganda. Both vaccines, expressing HIV-1 subtype A gag p24/p17 and a string of CD8 T-cell epitopes (HIVA), were generally safe and well-tolerated. At the dosage levels and intervals tested, the percentage of vaccine recipients with HIV-1-specific cell-mediated immune responses, assessed by a validated ex vivo interferon gamma (IFN-gamma) ELISPOT assay and Cytokine Flow Cytometry (CFC), did not significantly differ from placebo recipients. These trials demonstrated the feasibility of conducting high-quality Phase 1 trials in Africa.
Obiero, G.O, MS S. "Biotransformation of phenylnonane using Yarrowia lipolytica overexpressing a benzoate para-hydroxylase from R. minuta.". In: 14th Congress of the South African Microbiology Society. Pretoria, South Africa; 2006.
Obiero JA, Mburu MN, Ndung’u BM, Waititu KK, Farah IO, Mwethera PG. "UniPron is A Fully Effective Non-hormonal Reversible Contraceptive in Baboon Model (Papio Anubis).". Submitted. AbstractWebsite

Objective To determine the safety and efficacy of UniPron as a reversible contraceptive. Methods Vaginal swabs were obtained before and after UniPron administration, cultured onto appropriate culture media and bacteria identification was done based on type of media used, Gram stain reactions, colony morphology and biochemical tests. Vaginal biopsy tissues were processed using paraffin wax method, stained with hematoxylin and eosin and examined under light microscopy to determine the effect of the product on vaginal tissues. The effect of UniPron on sperm was examined by mixing the product with electroejaculated spermatozoa in vitro at different concentrations. For efficacy studies, male baboons of proven fertility were mated with UniPron treated or untreated females of proven fertility during the fertile stages. Results All the five females (100%) that were treated with UniPron did not conceive and they regained total fertility when the treatment was stopped while all the controls conceived. At a concentration of 40%,UniPron completely immobilized spermatozoa in an in-vitro system. UniPron mechanism of action was by lowering the vaginal pH and on application in baboon, the pH was lowered for at least 3 h after which it went back to normal. Conclusions As we plan for a study to test UniPron as a microbicide to prevent STIs including HIV, our current study has established that this novel product is effective in contraception and harmless to vaginal tissues and vaginal microbial flora in a baboon model (Papio anubis).

Obiero JA, Kunyera R WKKMFIOLJMPGIKW &. "A comparative study of Smugel and KY Jelly vaginal lubricating gels." Journal of Reproduction & Contraception. 2013;24(2):76-87.
Obiewo, J.O. KWDKDN. "Assimilation of Pollution Loading on Sosiani River in Eldoret Municipality, Kenya, as a Wastewater Management Strategy." American Journal of Water Resources. 2019;7(4):155-162.
OBIMBO DRLAMUKAPETER. "Effects of Lyophilized Thermophilus whey and Irradiation on Bacteriological quality of mechanically Deboned Chiken Meat. Abstract IFT Annual Meeting. Dallas Texas. June 1 .". In: Eur J. Biochem. Heinrich Boll Foundation.; 1991. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
Obimbo MM, Ogeng'o JA, Saidi H. "Comparative regional morphometric changes in human uterine artery before and during pregnancy." Pan Afr Med J. 2012;13:30. Abstract

Uterine artery undergoes structural modifications at different physiologic states. It is expected that due to its unique course, hemodynamic stresses in the vessel would vary resulting in differences in arterial dimensions. The objective of this study was to investigate regional morphometric changes in the human uterine artery.

OBIMBO DRLAMUKAPETER. "The role of liberalized dairy industry in rural development in Kenya. Paper presented at a seminar on .". In: Eur J. Biochem. Heinrich Boll Foundation.; 1996. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
OBIMBO DRLAMUKAPETER. "The potential role of Lactoperoxidase system in milk preservation for increased smallholder dairy production and Marketing in Kenya. Presented at RELMA Regional Workshop on Lactoperoxidase System, Nairobi, Kenya. March 27 .". In: Eur J. Biochem. Heinrich Boll Foundation.; 2000. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
Obimbo MM, Ogeng'o JA, Saidi H. "Comparative regional morphometric changes in human uterine artery before and during pregnancy." Pan Afr Med J. 2012;13:30. Abstract

Uterine artery undergoes structural modifications at different physiologic states. It is expected that due to its unique course, hemodynamic stresses in the vessel would vary resulting in differences in arterial dimensions. The objective of this study was to investigate regional morphometric changes in the human uterine artery.

Obimbo MM, Ogeng'o JA, Saidi H. "Comparative regional morphometric changes in human uterine artery before and during pregnancy." Pan Afr Med J. 2012;13:30. Abstract

Uterine artery undergoes structural modifications at different physiologic states. It is expected that due to its unique course, hemodynamic stresses in the vessel would vary resulting in differences in arterial dimensions. The objective of this study was to investigate regional morphometric changes in the human uterine artery.

Obimbo M. "Microscopic organization of male genital system.". In: Kimani Histology Text and Manual. Nairobi: University of Nairobi; 2014.
OBIMBO DRLAMUKAPETER. "Lamuka P.O., Sunki G.R., Rao D.R. and Shackelford L.A. 1991. Effects of Streptococcus thermophilus whey Fermented an Low Dose Irradiation on Microbiological quality and Self Life of chicken Carcasses. Abstract IFT Annual meeting. California. June 14 .". In: Eur J. Biochem. Heinrich Boll Foundation.; 1991. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
Obimbo MM, Ogeng'o JA, Saidi H. "Comparative regional morphometric changes in human uterine artery before and during pregnancy." Pan Afr Med J. 2012;13:30. Abstract

Uterine artery undergoes structural modifications at different physiologic states. It is expected that due to its unique course, hemodynamic stresses in the vessel would vary resulting in differences in arterial dimensions. The objective of this study was to investigate regional morphometric changes in the human uterine artery.

OBIMBO DRLAMUKAPETER. "Proceedings of National Workshop on .". In: Eur J. Biochem. Heinrich Boll Foundation.; 1993. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
OBIMBO DRLAMUKAPETER. "traditional cereal (maize) processing and preservation practicesl suing fermentation technology in Kenya: - A case study of Western Privince. In proceedings of workshop on .". In: Eur J. Biochem. Heinrich Boll Foundation.; 1999. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
Obimbo MM, Ogeng'o JA, Saidi H. "Variant anatomy of the uterine artery in a Kenyan population." Int J Gynaecol Obstet. 2010;111(1):49-52. Abstract

To investigate the uterine artery's origin, branching patterns, and relation to the ureter in a Kenyan population. METHOD: The uterine arteries of the bodies of 53 girls and women were dissected at the University of Nairobi Department of Human Anatomy to study these patterns. Data were analyzed for frequency and the patterns are presented via digital macrographs. RESULTS: The uterine artery consistently originated as a branch of the internal iliac artery. It formed the second or third branch of the anterior trunk in 70.8% of cases; it ascended as a single branch, or from a bifurcation, or from a trifurcation in 76.4%, 17.1%, and 6.7% of cases; and lay posterior to the ureter in 3.8% of cases. In all, 46.2% of the uterine arteries studied varied from the classic description. CONCLUSION: About half of the uterine arteries had a nonclassic origin, branching pattern, or relation to the ureter-as a posterior relation to the ureter had not been previously described. Surgeons operating in the pelvis should be aware of this variant anatomy to avoid injury to the ureter and other organs

Obimbo E, Musoke RN, Were F. "Knowledge, attitudes and practices of mothers and knowledge of health workers regarding care of the newborn umbilical cord." East Afr Med J. 1999;76(8):425-9. Abstract

To determine the knowledge, attitudes and practices (KAP) of mothers and the knowledge of health workers regarding care of the newborn umbilical cord.

Obimbo MM, Ogeng'o JA, Saidi H. "Variant anatomy of the uterine artery in a Kenyan population." Int J Gynaecol Obstet. 2010;111(1):49-52. Abstract

To investigate the uterine artery's origin, branching patterns, and relation to the ureter in a Kenyan population.

OBIMBO DRLAMUKAPETER. "The Potential Role of Lactoperoxidase systems in milk preservation for increased smallholder dairy production and marketing in Kenya. A study done for the smallholder Dairy Project (SDP), MOALD/KARI/ILRI/Collaborative Research programme.". In: Eur J. Biochem. Heinrich Boll Foundation.; 2001. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
Obimbo M. "Microscopic organization of Urinary system.". In: Kimani Histology Text and Manual. Nairobi: University of Nairobi; 2014.
OBIMBO DRLAMUKAPETER. "Effects of Streptococcus thermophilus Whey Fermented and Low Dose Irradiation on Microbiological Quality and Shelf Life of Chicken Carcasses. M.Sc thesis, Alabama A & M University, normal, Alabama 35762, U.S.A.". In: Eur J. Biochem. Heinrich Boll Foundation.; 1990. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
Obimbo MM, Omwandho C, Ogeng’o JA. "REGIONAL DIFFERENCES IN THE TUNICA MEDIA OF THE UTERINE ARTERY OF DOMESTIC PIG (Sus Scrofa Domesticus): BASIS FOR UTERINE BLOOD FLOW REGULATION." Anatomy Journal of Africa . 2015;4(1):505-511. AbstractREGIONAL DIFFERENCES IN THE TUNICA MEDIA OF THE UTERINE ARTERY OF DOMESTIC PIG (Sus Scrofa Domesticus): BASIS FOR UTERINE BLOOD FLOW REGULATIONWebsite

This study aimed at describing the structure of tunica media of the uterine artery of domestic
pig, since this structure influences the pattern of blood flow and reproductive performance.
Specimens were obtained from main trunk, broad ligament segment and the terminal portion
of twelve healthy adult domestic pigs (Sus scrofa domesticus) age range 6 – 18 months. They
were fixed in 10% formaldehyde solution, and routinely processed for paraffin embedding and
sectioning. Seven micron thick sections were stained with Hematoxylin & Eosin, Mason’s
Trichrome and Weigert resorcin fuchsin counterstained with Van Gieson stains. Tunica media
comprising predominantly smooth muscle occupied approximately fifty percent (50%) of the
volume of the entire wall with vasa vasora present deep into its inner zone. It showed zonal
and regional variation in that in the main trunk and broad ligament segments was divided into
inner two thirds having predominantly circular smooth muscle orientation while outer third
was preponderantly fibroelastic with longitudinally disposed smooth muscles. The terminal
segment had only circular layer. Density of vasa vasora declined distally. The predominantly
muscular tunica media of the uterine artery in pigs shows zonal and regional suggesting
segmental differentiation of function. The main trunk of this artery, due to its additional
longitudinal layer of smooth muscle may be involved in regulation of blood flow to the uterus
depending on the functional demands of the uterus.

OBIMBO DRLAMUKAPETER. "Bacteriological Quality of Freshly Processed broiler Chicken as Affected by Carcass Pretreatment and Gamma Irradiation. J. Food Sc. 57:330.". In: Eur J. Biochem. Heinrich Boll Foundation.; 1992. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
OBIMBO DRLAMUKAPETER. "Evaluation and review of bachelor of Science curricula in Food Science and Technology at Egerton University. Paper presented at Workshop on .". In: Eur J. Biochem. Heinrich Boll Foundation.; 1996. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
OBIMBO DRLAMUKAPETER. "Lamuka P.O. 2001. The Potential Role of Lactoperoxidase systems in milk preservation for increased smallholder dairy production and marketing in Kenya. A study done for the smallholder Dairy Project (SDP), MOALD/KARI/ILRI/Collaborative Research programme,.". In: Eur J. Biochem. Heinrich Boll Foundation.; 2001. Abstract
Thymidine kinase is an enzyme involved in DNA precursor metabolism and DNA replication. The synthesis of this enzyme is highly regulated during the cell cycle and the activity of the enzyme is also regulated by feedback inhibition. Genes encoding thymidine kinase have been extremely useful as selectable markers for introducing DNA into a number of cells. In order to study cell cycle regulation of thymidine kinase, the gene which encodes this enzyme, as well as aspects of DNA replication in the ciliated protozoan Tetrahymena thermophila, we have purified thymidine kinase from Tetrahymena. Two forms of thymidine kinase with native molecular masses of 59 kDa and 80 kDa have been identified and purified 6800- and 4600-fold, respectively. The 59-kDa enzyme, a homodimer of 30-kDa subunits, has been purified to near homogeneity and polyclonal antibodies have been raised against the 30-kDa subunit. Serological studies indicate that the two enzymes are antigenically distinct. The antibody against the Tetrahymena protein cross-reacts with a polypeptide in Chinese hamster ovary (CHO) cell extracts of 26 kDa which corresponds to the reported size of Chinese hamster thymidine kinase protein.
Obimbo EM, Wamalwa D, Richardson B, Mbori-Ngacha D, Overbaugh J, Otieno P, Bosire R, Payne BL, John-Stewart. "Pediatric HIV-1 in Kenya: pattern and correlates of viral load and association with mortality." J Acquir Immune DeficSyndr. 2009 Jun 1;51(2):209-15.. 2009. Abstract

Abstract
BACKGROUND:
There is limited information regarding the pattern and correlates of viral replication in vertically HIV-1-infected children and its role on their outcomes in resource-limited settings.
METHODS:
HIV-1-infected infants were followed from birth to 24 months. Serial HIV-1 RNA levels were compared in infants infected in utero (<48 hours), peripartum (48 hours-1 month), and late postnatal (after 1 month). Cofactors for viral peak [highest viral load (VL) within 6 months of infection] and set point and mortality were determined.
RESULTS:
Among 85 HIV-1-infected infants, 24 were infected in utero, 41 peripartum, 13 late postnatal; 7 had no 48-hour assay. HIV-1 VL set point was significantly lower in infants infected >1 month vs. < or = 1 month (5.59 vs. 6.24 log10 copies per milliliter, P = 0.01). Maternal VL correlated with peak infant VL (P < 0.001). Univariately, infant peak and set point VL and 6-month CD4% <15% predicted mortality; and 6-month CD4% <15% remained independently predictive in multivariate analyses (hazard ratio = 4.85, 95% confidence interval: 1.90 to 12.36).
CONCLUSIONS:
Infants infected after the age of 1 month contained virus better than infants infected before 1 month of age. Maternal VL predicted infant VL, which, in turn was associated with early mortality.

Obimbo MM, Y Z, MT MM, CR C, Z Q, J O’ech, JA O’o, SJ F. "Placental Structure in Preterm Birth Among HIV-Positive Versus HIV-Negative Women in Kenya." Journal of Acquired Immune Deficiency Syndromes. 2019;80(1):94-102. AbstractWebsite

Background: Preterm birth (PTB) is a major cause of infant morbidity and mortality in developing countries. Recent data suggest that in addition to Human Immunodeficiency Virus (HIV) infection, use of antiretroviral therapy (ART) increases the risk of PTB. As the mechanisms remain unexplored, we conducted this study to determine whether HIV and ART were associated with placental changes that could contribute to PTB.

Setting: We collected and evaluated placentas from 38 HIV-positive women on ART and 43 HIV-negative women who had preterm deliveries in Nairobi, Kenya.

Methods: Anatomical features of the placentas were examined at gross and microscopic levels. Cases were matched for gestational age and compared by the investigators who were blinded to maternal HIV serostatus.

Results: Among preterm placentas, HIV infection was significantly associated with thrombosis (P = 0.001), infarction (P = 0.032), anomalies in cord insertion (P = 0.02), gross evidence of membrane infection (P = 0.043), and reduced placental thickness (P = 0.010). Overall, preterm placentas in both groups were associated with immature villi, syncytial knotting, villitis, and deciduitis. Features of HIV-positive versus HIV-negative placentas included significant fibrinoid deposition with villus degeneration, syncytiotrophoblast delamination, red blood cell adhesion, hypervascularity, and reduction in both surface area and perimeter of the terminal villi.

Conclusions: These results imply that HIV infection and/or ART are associated with morphological changes in preterm placentas that contribute to delivery before 37 weeks. Hypervascularity suggests that the observed pathologies may be attributable, in part, to hypoxia. Further research to explore potential mechanisms will help elucidate the pathways that are involved perhaps pointing to interventions for decreasing the risk of prematurity among HIV-positive women.

Obino VK. "Natural Gas Hydrates: Technical Review and Prospects in Asia." International Journal of Engineering Research & Technology (IJERT). 2021;10(01):290-299.
Oboka, W. A. NMM, Awinja J. "Considerations for special needs groups in institutional disaster reduction plan: A Key to realization of the goals of Education for All.". International Journal of Disaster Management and Risk Reduction (IJDMRR). ISSN: 19922-2744. Vol. 2:2, pp. 39-47; 2010. Abstract
n/a
Oboko RO, Wagacha PW, Omwenga E, Odotte Z. "Non-obtrusive determination of learning styles in adaptive web-based learning." East African Journal of Information Sciences. 2009;1(2):19-31.Full Text
Oboko RO, Maina EM, Waiganjo PW, Omwenga EI, Wario RD. "Designing adaptive learning support through machine learning techniques.". In: IST-Africa Week Conference, 2016. IEEE; 2016. Abstract

The use of web 2.0 technologies in web based learning systems has made learning more learner-centered. In a learner centered environment, there is need to provide appropriate support to learners based on individual learner characteristics in order to maximize learning. This requires a Web-based learning system to have an adaptive interface to suit individual learner characteristics in order to accommodate diversity of learner needs and abilities and to maintain an appropriate context for interaction and for achieving personalized learning. The purpose of this paper is to discuss how machine learning techniques can provide adaptive learning support in a Web-based learning system. In this research, two machine learning algorithms namely: Heterogeneous Value Difference Metric (HVDM) and Naive Bayes Classifier (NBC) were used. HVDM was used to determine those learners who were similar to the current learner while NBC was used to estimate the likelihood that the learner would need to use additional materials for the current concept. To demonstrate the concept we used a course in object oriented programming (OOP).

Oboko RO, Njeng ST. "Use of Concept Map Scaffolds to Promote Adaptive E-Learning in Web-Based System." International Journal of computing and ICT Research. 2011;5(2):59-66. AbstractFull text link

Scaffolds are a good method of implementing self-regulated learning. Use of prior knowledge makes the
learner to understand a topic better. Learner adaptation enables a learner to be presented with content that
matches his/her level of understanding.
The main aim of this project is to use the adaptive scaffolds in form of concept maps in web-based elearning
systems to play the role of learner guide. The learner creates a concept map from prior knowledge
to show how he/she understands a certain domain of knowledge. The concept map takes into account the
knowledge of the learner in that topic, and uses it to adapt to the user level. This is done by integrated
evaluation where the learner is presented with a concept map that matches his level of understanding as
he/she draws the concept map. The scaffolding and the adaptation are implemented using production rules.
Categories and Subject Descriptions: H.5.2 [Information Interfaces and Presentation]: User Interfaces –
User Centered Design; H.5.4 [Information Interfaces and Presentation]: Hypertext/Hypermedia –
Navigation, User issues; I.2.6 [Artificial Intelligence]: Learning – Concept learning; Induction; K.3.1
[Computers and Education]: Computer Uses in Education – Distance Learning, Computer Assisted
Instruction (CAI); J.4 [Social and Behavioral sciences]: Psychology
General Terms: Algorithms, Human Factors, Experimentation, Measurement, Performance
Additional Key Words: Scaffold, adaptation, prior knowledge, learner evaluation, concept maps,
cognition, adaptive e-learning systems, adaptive scaffolds, integrated assessment.

Oboko RO, Wagacha PW. "Using Adaptive Link Hiding to Provide Learners with Additional Learning Materials in a Web-Based System for Teaching Object Oriented Programming. ." Journal of the Research Center for Educational Technology. 2012;8(1):11-25.
Oboko RO, Omwenga E, Wagacha P. "Using Adaptive Link Hiding to Provide Learners with Additional Learning Materials in a Web-Based System for Teaching Object Oriented Programming.". In: VLIR-IUC-UoN International Conference. Journal of School of Continuous and Distance Education ; 2009. Abstract

Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

Oboko RO, Wagacha PW, Omwenga EI, Odotte Z. Non-Obtrusive Determination of Learning styles in Adaptive Web-Based Learning..; 2009.
Oboko R, Wagacha PW, Omwenga EI, Libotton A. "Comparison of different machine learning algorithms for the initialization of student knowledge level in a learner model-based adaptive e-learning system." International Journal of computing and ICT Research. 2009;3(1):50-56. Abstract

Web-based learning systems give students the freedom to determine what to study based on each individual student’s learning goals. These systems support students in constructing their own knowledge for solving problems at hand. However, in the absence of instructors, students often need to be supported as they learn in ways that are tailored to suit a specific student. Adaptive web-based learning systems are suited to such situations. In order for an adaptive learning system to be able to provide learning support, it needs to build a model of each individual student and then to use the attribute values for each student as stored in the student model to determining the kind of learning support that is suitable for each student. Examples of such attributes are student knowledge level, learning styles, student errors committed during learning, the student’s program of study, gender and number of programming languages learned by the student of programming. There are two important issues about the use of student models. Firstly, how to initialize the attributes in the student models and secondly, how to update the attribute values of the student model as students interact with the learning system. With regard to initialization of student models, one of the approaches used is to input into a machine learning algorithm attribute values of students who are already using the system and who are similar (hence called neighbors) to the student whose model is being initialized. The algorithm will use these values to predict initial values for the attributes of a new student. Similarity among students is often expressed as the distance from one student to another. This distance is often determined using a heterogeneous function of Euclidean and Overlap measures (HOEM). This paper reports the results of an investigation on how HOEM compares to two different variations of Value Difference Metric (VDM) combined with the Euclidean measure (HVDM) using different numbers of neighbors. An adaptive web-based learning system teaching object oriented programming was used. HOEM was found to be more accurate than the two variations of HVDM.

Oboko RO, Wagacha PW, Masinde EM, Omwenga E, Libotton A. "Value difference metric for student knowledge level initialization in a learner model-based adaptive e-learning system." Strengthening the Role of ICT in Development. 2008:411. Abstract

Web-based learning systems give students the freedom to determine what to study based on
each individual learner's learning goals. These systems support learners in constructing
their own knowledge for solving problems at hand. However, in the absence of instructors,
learners often need to be supported as they learn in ways that are tailored to suit a specific
learner. Adaptive web-based learning systems fit in such situations. In order for an adaptive
learning system to be able to provide learning support, it needs to build a model of each

Oboko RO, Wagacha PW, Masinde EM, Omwenga E, Libotton A. Value Difference Metric for Student Knowledge Level initialization in a Learner Model-based Adaptive e-Learning System.; 2008. AbstractValue Difference Metric for Student Knowledge Level initialization in a Learner Model-based Adaptive e-Learning System

Web-based learning systems give students the freedom to determine what to study based on each individual learner’s learning goals. These systems support learners in constructing their own knowledge for solving problems at hand. However, in the absence of instructors, learners often need to be supported as they learn in ways that are tailored to suit a specific learner. Adaptive web-based learning systems fit in such situations. In order for an adaptive learning system to be able to provide learning support, it needs to build a model of each individual learner and then to use the attribute values for each learner as stored in the model to determining the kind of learning support that is suitable for each learner. Examples of such attributes are learner knowledge level, learning styles and learner errors committed by learners during learning. There are two important issues about the use of learner models. Firstly, how to initialize the attributes in the learner models and secondly, how to update the attribute values of the learner model as learners interact with the learning system. With regard to initialization of learner models, one of the approaches used is to input into a machine learning algorithm attribute values of learners who are already using the system and who are similar (hence called neighbors) to the learner whose model is being initialized. The algorithm will use these values to predict initial values for the attributes of a new learner. Similarity among learners is often expressed as the distance from one learner to another. This distance is often determined using a heterogeneous function of Euclidean and Overlap measures (HOEM). This paper reports the results of an investigation on how HOEM compares to two different variations of Value Difference Metric (VDM) combined with the Euclidean measure (HVDM) using different numbers of neighbors. An adaptive web-based learning system teaching object oriented programming was used. HOEM was found to be more accurate than the two variations of HVDM

Oboko RO, Wagacha PW, Omwenga E. "Comparison of Different Machine Learning Algorithms for the Initialization of Student Knowledge Level in a Learner Model-Based Adaptive E-Learning System.". 2009. AbstractFull text link

Web-based learning systems give students the freedom to determine what to study based on each individual student’s learning goals. These systems support students in constructing their own knowledge for solving problems at hand. However, in the absence of instructors, students often need to be supported as they learn in ways that are tailored to suit a specific student. Adaptive web-based learning systems are suited to such situations. In order for an adaptive learning system to be able to provide learning support, it needs to build a model of each individual student and then to use the attribute values for each student as stored in the student model to determining the kind of learning support that is suitable for each student. Examples of such attributes are student knowledge level, learning styles, student errors committed during learning, the student’s program of study, gender and number of programming languages learned by the student of programming. There are two important issues about the use of student models. Firstly, how to initialize the attributes in the student models and secondly, how to update the attribute values of the student model as students interact with the learning system. With regard to initialization of student models, one of the approaches used is to input into a machine learning algorithm attribute values of students who are already using the system and who are similar (hence called neighbors) to the student whose model is being initialized. The algorithm will use these values to predict initial values for the attributes of a new student. Similarity among students is often expressed as the distance from one student to another. This distance is often determined using a heterogeneous function of Euclidean and Overlap measures (HOEM). This paper reports the results of an investigation on how HOEM compares to two different variations of Value Difference Metric (VDM) combined with the Euclidean measure (HVDM) using different numbers of neighbors. An adaptive web-based learning system teaching object oriented programming was used. HOEM was found to be more accurate than the two variations of HVDM. Categories and Subject Descriptions: H.5.2 [Information Interfaces and Presentation]: User Interfaces – User Centered Design; H.5.4 [Information Interfaces and Presentation]: Hypertext/Hypermedia-Navigation, User issues; I.2.6 [Artificial Intelligence]: Learning – Concept learning; Induction; K.3.1 [Computers and Education]: Computer Uses in Education – Distance Learning, Computer Assisted Instruction (CAI) General Terms: Algorithms, Human Factors, Experimentation, Measurement Additional Key Words: Learner modeling, initialization, web-based learning, nearest neighbors, overlap measure, knowledge level, object oriented programming, value difference metric.

Oboko R, Omwenga E. "A model for evaluating e-learning systems quality in higher education in developing countries Kennedy Hadullo Technical University of Mombasa, Kenya." International Journal of Education and Development using Information and Communication Technology. 2017;13(2). Abstract

The rapid growth of Information and Communication Technology (ICT) has
brought about significant changes in the practice of e-learning globally. In recent years,
there has been an increasing adoption of Learning Management System (LMS) assisted e-
learning in higher education institutions (HEIs) in developing countries. Despite the
perceived benefits attached to e-learning, several studies concur that there are still many
challenges facing e-learning.

Oboko RO, Wagacha PW, Omwenga EI, Odotte Z. Non-Obtrusive Determination of Learning styles in Adaptive Web-Based Learning..; 2009.
Oboko R, Omwenga E. "Factors affecting asynchronous e-learning quality in developing countries. A qualitative pre-study of JKUAT University Kennedy Hadullo Technical University of Mombasa, Kenya." International Journal of Education and Development using Information and Communication Technology. 2018;14(1): 152-163. Abstract

The purpose of the present study was to identify the influencing factors of asynchronous
elearning system quality particular in developing countries via a review of current literature
and a qualitative pre-study conducted at Jomo Kenyatta University of Agriculture and
Technology (JKUAT). Despite the perceived benefits of these systems to overcome
challenges facing education sector in the region, studies show that the majority of them have
not been successful. After a thorough review of existing literature on developing countries
and a qualitative pre-study conducted at JKUAT University, the study identified the factors
that influence quality of e-learning systems as: Course Design, Content support, social
support, and Student Characteristics, Instructor Characteristics, Technician Characteristics,
Course Assessment and Institutional factors.

Obondo A, Karani A, Wagoro MA. "Rehabilitation and community mental health.". 200. Abstract

Cerebral venous sinus thrombosis is an uncommon yet potentially life threatening condition which is often under-diagnosed or misdiagnosed because of the variability of the clinical signs and symptoms. The imaging findings are often subtle thus the need for a high index of suspicion. The superior sagittal and transverse sinuses are the most frequently involved. The correct diagnosis of cerebral venous thrombosis relies on neuroimaging studies. The two cases reported highlight the fact that the radiologist may be the first clinician to suspect and diagnose this condition. This ultimately affects prognosis as early diagnosis and treatment reduces morbidity and mortality.

Obondo A, Ngare D, Ndetei DM, Mbewe E, Morakinyo O, Rono R, Addo AS. "Human Development and Life Cycle."; 2006.
Obondo A, Khasakhala L, editor Ndetei DM, Mutiso V, Ongecha-Owuor F. "Communication and Communication Skills."; 2006.
Obondo A, Karani A, Wagoro MA. "Rehabilitation and community mental health.". 200. Abstract

Cerebral venous sinus thrombosis is an uncommon yet potentially life threatening condition which is often under-diagnosed or misdiagnosed because of the variability of the clinical signs and symptoms. The imaging findings are often subtle thus the need for a high index of suspicion. The superior sagittal and transverse sinuses are the most frequently involved. The correct diagnosis of cerebral venous thrombosis relies on neuroimaging studies. The two cases reported highlight the fact that the radiologist may be the first clinician to suspect and diagnose this condition. This ultimately affects prognosis as early diagnosis and treatment reduces morbidity and mortality.

Obondo A, Karani A, Wagoro MA. "Rehabilitation and community mental health.". 200. Abstract

Cerebral venous sinus thrombosis is an uncommon yet potentially life threatening condition which is often under-diagnosed or misdiagnosed because of the variability of the clinical signs and symptoms. The imaging findings are often subtle thus the need for a high index of suspicion. The superior sagittal and transverse sinuses are the most frequently involved. The correct diagnosis of cerebral venous thrombosis relies on neuroimaging studies. The two cases reported highlight the fact that the radiologist may be the first clinician to suspect and diagnose this condition. This ultimately affects prognosis as early diagnosis and treatment reduces morbidity and mortality.

Obondo A, editor Ndetei, D.M., Rono R, Ngare D. "Loss and Bereavement Therapies."; 2006.
Obonyo N, Cheroigin K, Kariuki M, Sumuni K, Lang’at O, Njogu B, Masika M, Patel N. "The Effects of MÛGÛKA (Catha edulis vahl) on the Behaviour of Rats." Nairobi Journal of Medicine. 2006. Abstractabstract_-_the_effects_of_muguka_on_rats.pdfeffects_of_muguka_catha_edulis_vahl_on_the_behavior_of_rats-_nairobi_journal_of_medicine_jun_2006.pdf

The Effects of MÛGÛKA (Catha edulis vahl) on the Behaviour of Rats

N.G Obonyo, K.S Cheroigin, M.M Kariuki, K.M Sumuni, O Lang’at, Njogu, M.M Masika, N.B Patel

INTRODUCTION: Mûgûka (Catha edulis vahl) are ‘residue’ leaves, which are chewed to elicit a stimulant effect. It is grown in Eastern province (mostly in Mbeere and Embu districts) of Kenya and is very popular with the local residents in this part of the country. It is closely related to miraa (Catha edulis forsk), which is reported to be one of the most recklessly abused drugs in Kenya by NACADA (National Agency for the Campaign Against Drug Abuse). Whereas lots of research has been done on miraa, little, if any, research has been done on mûgûka.

OBJECTIVE: To determine the effects of mûgûka on the behaviour of Sprague Dawley rats.

MATERIALS AND METHODS: Five Sprague Dawley rats were used. The experiment was divided into three phases: Baseline, Normal saline and Mûgûka. Baseline phase established the normal behaviour of the rats before injection of mûgûka plant extract (mûgûka phase). Normal saline was used as a control. We conducted an Open field Test. The behaviours exhibited during a 30-minute trial were recorded for each of the experimental phases. The four behavioural parameters recorded for each experimental phase were line crossings, rearing counts, grooming time and defecation pellets count.

RESULTS: The behavioural changes noted after injection of mûgûka plant extract were; the line crossing counts increased but the grooming time, rearing counts and defecation pellet counts decreased. However, none of these changes was statistically significant. Sniffing behaviour was also markedly increased when the mûgûka was administered.

DISCUSSION: The results obtained above suggest that there are changes in the behavioural parameters although they are not statistically significant. The sample size probably needs to be increased and serial dose-response measurements for the injected mûgûka plant extract need to be done.

Keywords: Mûgûka (Catha edulis vahl), miraa (Catha edulis forsk), NACADA (National Agency for the Campaign Against Drug Abuse) in Kenya

Published in the Nairobi Journal of Medicine, June 2006

Obonyo J, Olungah CO, Omia DO. "Fait accompli: Legitimizing the illegitimate in elections outcomes. Does the legality of the electoral process matter in Kenya?" Journal of Public Policy and Administration Research. 2015;5(4):103-107.
Obonyo FO, Maingi N, Githigia SM, Nganga CJ. "Prevalence, intensity and spectrum of helminths of free range pigs in Homabay District, Kenya." Livestock Research for Rural Development. 2012;24.4_obonyo_et_al_2012.pdf
Obonyo FO, Maingi N, Githigia SM, Ng’ang’a CJ. "Farming practices and risk factors for transmission of helminths of free range pigs in Homabay District, Kenya." Livestock Research for Rural Development.. 2013;25.Obonyo_et_al_2013.pdf
Obonyo J, Olungah CO, Omia DO. "Beyond remedial measures: Rethinking normalization of women's elections as part of the political experience in Kenya." Journal of International Affairs and Global Strategy. 2012;33:33-41.
Obonyo J. B., et al. "Kenya 2009 Population and Housing Census Analytical Report on Projections of Special Population Groups, 2010-2030,." Kenya National Bureau of Statistics, Ministry of Planning, National Development and Vision 2030. 2012;Vol. XI‛.
Obonyo J. B., O. AA, M. NS. "Kenya 2009 Population and Housing Census Analytical Report on Population Projections,." Kenya National Bureau of Statistics, Ministry of Planning, National Development and Vision 2030, Nairobi.. 2011;Vol. VI.
Obonyo" "CO-, Karanja" "JG, Bashir" "I, Odawa" "F, Beatrice" "KA-. "KOGS - Legal and policy reform for safe abortion.". In: Kenya Obstetrics and Gynecology Society 36th Conference. Safari Park Hotel, Nairobi; 2012.
Obosi OJ. "Public Private Partnetships in the Privatization of Water Service Delivery in Kenya.". In: Current Issues of Water Management. Rijeka: Intech; 2011. Abstract

Key words: Public - Private Partnerships, Privatization, Water service delivery
The Government of Kenya has introduced several water reforms in the provision of
water services since independence in 1963. The Local Government Act Chapter 165
of the laws of Kenya granted local authorities powers to engage in water services
provision especially in urban areas (Republic of Kenya, 1986b). The Water Act of
2002 introduced far reaching reforms in the water sector in terms of management and
provision services. It commercialized the provision of water services by forming
Public Limited Companies (PLCs) owned by respective local authorities. It also
allowed private sector participation in the provision of services. Individual companies
and communities have also been permitted to seek license from Water Services
Regulatory Board (WSRB) to provide water services to the public. Among the
private sector actors are independent water service Providers in the form of
community water projects, Private bore-holes, Water tankers, and Water kiosks.
Community water projects request for funds for putting up water projects from a state
organ known as Water Services Trust Fund (WSTF), hence the Public –Private
Partnerships. The paper examines the effectiveness of the existing policy and
institutional framework for the management of privatized water service delivery.
The paper particularly examines institutional monitoring mechanisms in ensuring
clean quality water is supplied to the unsuspecting poor. Are there clear mechanisms
in which the public through the state institutions regulate the water service provision
by private actors, as a requirement, before water is released to the public? How can
the private sector be made accountable for offering public goods.
The study has drawn its data from secondary data of randomly selected ten (10)
independent water service providers registered under two of the eight (8) Water
Service Boards (WSBs) in Kenya, namely, Rift Valley Water Service Board
(RVVWSB), and Athi Water Service Board (AWSB). The data was drawn from the
existing secondary data and was analyzed through content Analysis.
The paper has utilized the World Bank framework for the provision of transaction
intensive services as its analytical framework where water is taken as a transactionintensive
service with ministry of Water Development and Irrigation being policy
maker. Provider organizations include Water Resource Management authority
(WRMA), Water Service Regulatory board (WSRB), and Water Service Boards
(WSBs) as water providers. Water Service Providers (WSPs) are agents of WSBs.
WSPs include PLCs registered by the respective local authorities, and independent
ones including Community Water projects, and Water Kiosks.
The paper is expected to among others, identify and explain some role overlaps
between WRMA and WSBs since both can set water tariffs and there are weak
institutional arrangements to monitor the effectiveness and efficiency in the
operations of the independent water service providers.

Obosi J. The Public Service Delivery Challenge: A Public-Private Sector Partnership In Water Service Provision In The Lake Victoria Basin, Kenya. Nairobi: University of Nairobi; 2013. Abstractphd_thesis.-_joseph_okeyo_obosi_.pdf

The study investigated how public-private partnership arrangements have perfomed in the provision of water services in Kenya. This is with a view to explain the extent to which this increasingly preferred public service delivery approach has improved access to water in terms of coverage, affordability, quality of water and customer service.

The broad objective of the study was to investigate outcomes of the Private -Public Partnership policy for provision of water as a public good as a challenge in Kenya. Specific objectives are as follows: First, to analyze the nature and scope of Public- Private Partnership arrangements in the water sector; secondly, to examine the gains from organizational managerial strategies in the provision of water services, and finally, to analyse appropriate interventions adopted to enhance the accessibility of water services notably by vulnerable consumers.

The study used secondary data and primary data from a household survey of 288 respondents, seven (7) Focus Group Discussions, and 28 Key informant interviews from seven (7) WSPs (Mogombet, Chemosit, Boya, KIWASCO, SNWSCO, MIKUTRA and Nyasare) of the Lake Victoria South Water Services Board (LVSWSB) umbrella. The study was conducted under two mutually reinforcing theories: governance theory and public choice theory. We used both qualitative and quantitative techniques to analyze the data. The techniques included use of content analysis of secondary data, frequency tables and cross tabulations to measure the central tendencies and dispersions.

The main finding was that public institutions that have adopted more private sector participation have performed better than those that have not, hence the more the public private sector partnership, the better the quality of public service delivery.
Highlights of findings specificically include the following: that there are various stakeholders, both institutional and individual involved in water service provision either through interventions or as facilitators, for example, the government through WSTF provides funds to community water projects in the provision of water services.; there is more private participation independence as WSPs increasingly become less involved together with the government in service operations and management; the existing policy on organization of water resources management does not guarantee effective popular participation given the formal governance structure; community water projects with more public private sector participation implemented better, on average, the required managerial strategies such as Enterprise Design; Operational roles; Network management; and Human resource functions.

The study recommended first, a realignment of the national water regulatory agency (WSRB) to be in charge of both service provision and resource management. Secondly, the “Service Provider” role of the state should be changed to that of a regulator of services and facilitator. The idea is to make a shift which necessitates strengthening of institutions responsible for planning, implementation and management of water resources. Water service operation should be left to the community and private operators. Third, the Water Service Trust Fund (WSTF) funding level should be enhanced substantially to finance community or private water operators with viable proposals to provide water to the community without having to go through Water Service Boards.

Obosi OJOO& A. "Public Private Partnerships as a redistributive strategy in in University Education in Kenya." International Journal Of Innovative Knowledge and Research . 2018;3(9):44-55.
Obosi OJ. "Public-Private Partnerships in Kenya’s Water Sector Management.". In: Global Encyclopedia of Public Administration, Public Policy, and Governance . Springer; 2017.
Obosi JO. The provincial administration and the Democratisation of development process In kenya. Nairobi: University of Nairobi; 2003. Abstractmath.pdfma_thesis.pdf

This study is an attempt to investigate the emergence of the new actors such as Non Governmental Organizations (NGOs) and (Peoples Organizations) POs in the development space and their impact on the developmental role of the Provincial Administration in Kenya. The following objectives were formulated: First, to investigate the nature of the relationship between the civil society (NGOs and POs) as new actors in the development process, and the Provincial Administration (PA). Second, to examine the current development tasks of the Provincial Administration. Thirdly, to examine the impact of the democratization of the development process on PA with specific reference to the development activities of a given locality, and fourth, to investigate the impact of the emergence of the new actors (NGOs and POs) in the development space on popular participation.
This was done within the theoretical framework of development theories including statism and public or political choice. The study did not however lose sight of the fact that development still attracts both academic and policy debates that definitely have a bearing on the formulation of both development theory and/or policy in the light of the shifting world development thinking.

The study used both secondary data, and primary data obtained from surveys conducted in Nyamira, Nairobi and Migori districts in Kenya. The sample survey comprised a total of seventy-two respondents from all the three districts. The secondary data was analysed by use of content analysis. The survey data was coded and analyzed through cross tabulations of the frequencies and the results presented in table statistics form.

The main findings of the study were as follows: First, the increased democratization of the development process has called for a greater role for the Provincial Administration in development activities, especially in areas of security, advisory and mobilization of the local public. Secondly, it was found that an enhanced level of co-ordination of various project activities in the locality, liaison with other governmental agencies on behalf of local POs and NGOs are some of the new roles of the Provincial Administration. This is besides the traditional routine law and order roles of provision of security and mobilization of local population. Thirdly, the level of involvement of Provincial Administration is directly proportional to the level of popular participation in the development activities. Finally, the study found out that the level of involvement of civil society in the development activities is directly proportional to the level of popular participation in the development process provided the necessary level of party affiliation and involvement of Provincial Administration is sustained.

Finally, the study has recommended further research on the policy implementation consequences of liberalization of security arrangements and the role to be played by the Provincial Administration, and the need to investigate the impact of significant rise in the number of political parties on popular participation. The study recommended to the policy makers, especially government to consider: the training and retraining of Provincial Administrators to attain the required standards of professionalism; initiate and support policies to make development a shared responsibility of the PA and POs as the key players at the local level, and finally to formulate development policies tailored to different areas reflecting the socio-economic structural forms, wishes and needs of all the local stakeholders.

Obosi OJ. "Decentralized Governance in the Management of Urban Health Care Systems in Developing Countries." Open Journal Of Political Science. 2019;9(1):189-202.
Obudho RA. "Urbanization Process and the Spread of STDs, HIV and AIDS in Africa.". 2003. Abstract

It is well known that levels of HIV prevalence tend to be appreciably higher inurban areas. This article considers the reasons for this and shows that within world regions that are relatively homogeneous with respect to their experience of HIV/AIDS, variation in the level of urbanization corresponds to about one-third of variation in estimated HIV prevalence. Furthermore, for populations in the world's worst-affected area—eastern and southern Africa—there are signs that, partly by differentially raising urban death rates and depressing urban birth rates, HIV/AIDS is slowing the pace of urbanization. Finally, in countries with very high levels of HIV infection and relatively low birth rates, such as in South Africa, the urban sector will soon constitute a “demographic sink”—with death rates exceeding birth rates.

UoN Websites Search