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Search Results: 1 - 10 of 23815 matches for " Paul Onyango Ouma "
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Spatial Modelling of Weather Variables for Plant Disease Applications in Mwea Region  [PDF]
Paul Onyango Ouma, Patroba Achola Odera, John Bosco Mukundi
Journal of Geoscience and Environment Protection (GEP) , 2016, DOI: 10.4236/gep.2016.45013
Abstract: Climate change is expected to affect the agricultural systems, such as crop yield and plant disease occurrence and spread. To be able to mitigate against the negative impacts of climate change, there is a need to use early warning systems that account for expected changes in weather variables such as temperature and rainfall. Moreover, providing such information at high spatial and temporal resolutions can be useful in improving the accuracy of an early warning system. This paper describes a methodology that can be used to produce high spatial and temporal resolutions of minimum temperature, maximum temperature and rainfall in an agricultural area. We utilize MarkSim GCM, a weather file generator that incorporates IPCC based climate change models to downscale the weather variables at monthly intervals. An ensemble of 17 GCM models is used within the RCP 8.0 emission scenario within the latest model based CMIP5. We first assess the usability of the model, by comparing results produced to what has been recorded at weather station level over a vast region. Then, we estimate the correction factors for model results by implementing a linear regression that is used to assess the relationship between the variables and the deviation of model outputs to the weather station data. Finally, we use kriging geostatistical technique to interpolate the weather data, for the year 2010. Results indicated that the model overestimated the results of maximum temperature, while underestimating the result of minimum temperature. Variability in the recorded weather variables was also evident, indicating that the response variables such as plant disease severity dependent on such weather information could vary in the area. These datasets can be useful especially in predicting the occurrence of plant diseases, which are affected by either rainfall or temperature.
Estimating a Finite Population Mean under Random Non-Response in Two Stage Cluster Sampling with Replacement  [PDF]
Nelson Kiprono Bii, Christopher Ouma Onyango, John Odhiambo
Open Journal of Statistics (OJS) , 2017, DOI: 10.4236/ojs.2017.75059
Abstract: Non-response is a regular occurrence in Sample Surveys. Developing estimators when non-response exists may result in large biases when estimating population parameters. In this paper, a finite population mean is estimated when non-response exists randomly under two stage cluster sampling with replacement. It is assumed that non-response arises in the survey variable in the second stage of cluster sampling. Weighting method of compensating for non-response is applied. Asymptotic properties of the proposed estimator of the population mean are derived. Under mild assumptions, the estimator is shown to be asymptotically consistent.
Christopher Ouma Onyango,Romanus Odhiambo Otieno,George Otieno Orwa
Pakistan Journal of Statistics and Operation Research , 2010, DOI: 10.1234/pjsor.v6i2.128
Abstract: Chambers and Dorfman (2002) constructed bootstrap confidence intervals in model based estimation for finite population totals assuming that auxiliary values are available throughout a target population and that the auxiliary values are independent. They also assumed that the cluster sizes are known throughout the target population. We now extend to two stage sampling in which the cluster sizes are known only for the sampled clusters, and we therefore predict the unobserved part of the population total. Jan and Elinor (2008) have done similar work, but unlike them, we use a general model, in which the auxiliary values are not necessarily independent. We demonstrate that the asymptotic properties of our proposed estimator and its coverage rates are better than those constructed under the model assisted local polynomial regression model.
Systematic Monitoring of Male Circumcision Scale-Up in Nyanza, Kenya: Exploratory Factor Analysis of Service Quality Instrument and Performance Ranking
Dickens S. Omondi Aduda, Collins Ouma, Rosebella Onyango, Mathews Onyango, Jane Bertrand
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0101235
Abstract: Background Considerable conceptual and operational complexities related to service quality measurements and variability in delivery contexts of scaled-up medical male circumcision, pose real challenges to monitoring implementation of quality and safety. Clarifying latent factors of the quality instruments can enhance contextual applicability and the likelihood that observed service outcomes are appropriately assessed. Objective To explore factors underlying SYMMACS service quality assessment tool (adopted from the WHO VMMC quality toolkit) and; determine service quality performance using composite quality index derived from the latent factors. Study design Using a comparative process evaluation of Voluntary Medical Male Circumcision Scale-Up in Kenya site level data was collected among health facilities providing VMMC over two years. Systematic Monitoring of the Medical Male Circumcision Scale-Up quality instrument was used to assess availability of guidelines, supplies and equipment, infection control, and continuity of care services. Exploratory factor analysis was performed to clarify quality structure. Results Fifty four items and 246 responses were analyzed. Based on Eigenvalue >1.00 cut-off, factors 1, 2 & 3 were retained each respectively having eigenvalues of 5.78; 4.29; 2.99. These cumulatively accounted for 29.1% of the total variance (12.9%; 9.5%; 6.7%) with final communality estimates being 13.06. Using a cut-off factor loading value of ≥0.4, fifteen items loading on factor 1, five on factor 2 and one on factor 3 were retained. Factor 1closely relates to preparedness to deliver safe male circumcisions while factor two depicts skilled task performance and compliance with protocols. Of the 28 facilities, 32% attained between 90th and 95th percentile (excellent); 45% between 50th and 75th percentiles (average) and 14.3% below 25th percentile (poor). Conclusion the service quality assessment instrument may be simplified to have nearly 20 items that relate more closely to service outcomes. Ranking of facilities and circumcision procedure using a composite index based on these items indicates that majority performed above average.
Accountable priority setting for trust in health systems - the need for research into a new approach for strengthening sustainable health action in developing countries
Jens Byskov, Paul Bloch, Astrid Blystad, Anna-Karin Hurtig, Knut Fylkesnes, Peter Kamuzora, Yeri Kombe, Gunnar Kv?le, Bruno Marchal, Douglas K Martin, Charles Michelo, Benedict Ndawi, Thabale J Ngulube, Isaac Nyamongo, ?ystein E Olsen, Washington Onyango-Ouma, Ingvild F Sand?y, Elizabeth H Shayo, Gavin Silwamba, Nils Songstad, Mary Tuba
Health Research Policy and Systems , 2009, DOI: 10.1186/1478-4505-7-23
Abstract: Accountability for Reasonableness (AFR) is an explicit ethical framework for legitimate and fair priority setting that provides guidance for decision-makers who must identify and consider the full range of relevant values. AFR consists of four conditions: i) relevance to the local setting, decided by agreed criteria; ii) publicizing priority-setting decisions and the reasons behind them; iii) the establishment of revisions/appeal mechanisms for challenging and revising decisions; iv) the provision of leadership to ensure that the first three conditions are met.REACT - "REsponse to ACcountable priority setting for Trust in health systems" is an EU-funded five-year intervention study started in 2006, which is testing the application and effects of the AFR approach in one district each in Kenya, Tanzania and Zambia. The objectives of REACT are to describe and evaluate district-level priority setting, to develop and implement improvement strategies guided by AFR and to measure their effect on quality, equity and trust indicators. Effects are monitored within selected disease and programme interventions and services and within human resources and health systems management. Qualitative and quantitative methods are being applied in an action research framework to examine the potential of AFR to support sustainable improvements to health systems performance.This paper reports on the project design and progress and argues that there is a high need for research into legitimate and fair priority setting to improve the knowledge base for achieving sustainable improvements in health outcomes.Efforts to strengthen district level planning in poorer countries using technical approaches based on burden of disease measures, cost effectiveness analysis, and capacity considerations have not achieved intended sustainable improvements [1]. They emphasize a narrow range of values without reaching neither adequate consensus between them nor the desired acceptance and changes at the operati
Knowledge, Attitudes and Practices (KAP) on Rift Valley Fever among Pastoralist Communities of Ijara District, North Eastern Kenya
Is H. Abdi?,Hippolyte D. Affognon?,Anthony K. Wanjoya?,Washington Onyango-Ouma,Rosemary Sang
PLOS Neglected Tropical Diseases , 2015, DOI: 10.1371/journal.pntd.0004239
Abstract: Outbreaks of Rift Valley fever (RVF), a mosquito-borne viral zoonosis, have previously been associated with unusually heavy rainfall and extensive flooding. The disease is a serious public health problem in Africa and the Middle East, and is a potential global health threat. In Kenya, outbreaks of the disease have disproportionately affected impoverished pastoralist communities. This study sought to assess the knowledge, attitudes and practices (KAP) regarding RVF among the pastoralists of North Eastern Kenya, and to establish the determinants of KAP on RVF. A cross-sectional study involving 392 pastoralists living in Ijara district (Masalani and Ijara wards) was carried out using an interview questionnaire. All respondents interviewed (100%) had heard about RVF disease. They recognized that the disease is dangerous (99%), and had a positive attitude towards vaccination of animals (77%). However, few respondents knew that abortion (11%) and high mortality of young animals (10%) were key signs of RVF in animals. Very few (4%) use any form of protection when handling sick animals to avoid infection. Significant factors associated with knowledge were being in a household with a history of RVF infection (OR = 1.262, 95% CI = 1.099–1.447), having more livestock (OR = 1.285, 95% CI = 1.175–1.404) and the place of residence, Masalani (OR = 0.526, 95% CI = 0.480–0.576). Overall knowledge score on RVF was found to be a significant predictor of good preventive practice of the disease (OR = 1.073, 95% CI = 1.047–1.101). Despite the positive attitude that pastoralist communities have towards the prevention of RVF, there exist gaps in knowledge and good practices on the disease. Therefore there is need for public health education to address these gaps, and to identify and facilitate the removal of barriers to behavioural change related to the prevention of RVF.
An exploration of extra linguistic factors of English – Kiswahili code switching in FM Industry in Kenya
OR Onyango
Journal of Language, Technology & Entrepreneurship in Africa , 2009,
Abstract: The paper examines English and Kiswahili Code-switching (CS) in Kiss Fm and Easy Fm radio stations in Kenya.CS is a recently formed practice in Fm stations in Kenya. Liberalization of the air waves led to a shift in the language of broadcasting among the Fm anchors unlike the previous years when broadcasters used English exclusively .The new stations started switching language during their shows. Since then, several Fm stations have adopted CS during their programmes to communicate with the Fm listeners and various audiences. In this study, we examine the motivations of Fm anchors to code switch and whether the specific extralinguistic factors contribute to such code switching. Data from naturally- occurring conversations by four Fm anchors are analyzed within Blom and Gumperz (1972) interactional/Interpretative model. An attempt is also made to demonstrate that code-switching in Fm stations is influenced by extralinguistic factors.Fm anchors are found to use CS as a communication strategy employed for effective communication between Fm anchors and Fm listeners . The data set for this work came from four FM anchors in the two FM stations sampled through purposive sampling and ten Maseno University Student selected through snow ball sampling technique..
Freedom and poverty in the fishery commons
Svein Jentoft,Paul Onyango,Mohammad Mahmudul Islam
International Journal of the Commons , 2010,
Abstract: In fisheries, alleviating poverty sometimes requires strategies that are inherently in conflict. When aiming to develop a fishery as a means to reduce poverty, its common pool resource basis might be undermined, resulting in greater poverty. But poverty in fisheries is also linked to, or a part of deeper social issues and processes, for instance, the marginalization and exclusion of certain communities. Poverty also has many factors— income, health, literacy, gender, power, security, etc.—all of which make poverty alleviation a particularly “wicked problem” that would require a broad process of political, social and institutional reform. In other words, poverty alleviation is not only an issue of sustainable resource management but also one of societal governance. Drawing from research in small-scale fisheries communities in Nicaragua, Tanzania, and Bangladesh, this paper describes how fishing people cope with poverty. The paper discusses what the governance implications are for alleviating poverty at individual, household and community levels, and argue that both the definition of poverty and poverty alleviation in small-scale fisheries must be rooted in real life experiences.
Factors associated with non-adherence to Artemisinin-based combination therapy (ACT) to malaria in a rural population from holoendemic region of western Kenya
Elizabeth O Onyango, George Ayodo, Carren A Watsierah, Tom Were, Wilson Okumu, Samuel B Anyona, Evans Raballah, John M Okoth, Sussy Gumo, George O Orinda, Collins Ouma
BMC Infectious Diseases , 2012, DOI: 10.1186/1471-2334-12-143
Abstract: ACT Adherence level was assessed with reference to the duration of treatment and number of tablets taken. Using systematic random sampling technique, a questionnaire was administered to a particular household member who had the most recent malaria episode (<2?weeks) and used ACT for cure. Parents/caretakers provided information for children aged <13?years. Key Informant Interviews (KIIs) were also conducted with healthcare providers and private dispensing chemist operators.Adherence to ACT prescription remained low at 42.1% and 57.9% among individuals above 13 and less than 13?years, respectively. Stratification by demographic and socio-economic characteristics in relation to ACT adherence revealed that age (P?=?0.011), education level (P?<?0.01), ability to read (P?<?0.01) and household (HH) monthly income (P?=?0.002) significantly affected the level of ACT adherence. Consistently, logistic regression model demonstrated that low age (OR, 0.571, 95% CI, 0.360-0.905; P?=?0.017), higher education level (OR, 0.074; 95% CI 0.017-0.322; P?<?0.01), ability to read (OR, 0.285, 95% CI, 0.167-0.486; P?<?0.01) and higher income (Ksh.?>?9000; OR, 0.340; 95% CI, 0.167-0.694; P?=?0.003) were associated with ACT adherence. In addition, about 52.9% of the respondents reported that ACT was not always available at the source and that drug availability (P?=?0.020) and distance to drug source (P?<?0.01) significantly affected accessibility.This study demonstrates that more than half of those who get ACT prescription do not take recommended dose and that accessibility is of concern. The findings of this study suggest a potential need to improve accessibility and also initiate programmatic interventions to encourage patient-centred care.
Multiple Endemic Solutions in an Epidemic Hepatitis B Model without Vertical Transmission  [PDF]
Nelson Owuor Onyango
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.516242

This paper examines the dynamics of Hepatitis B via a Susceptible Exposed Infectious Recovered (SEIR) type epidemic model. Previous studies have shown that Hepatitis B is characterized by multiple endemic solutions, a matter which may be of concern in developing control strategies. We identify the possible causes of multiple endemic solutions in a Hepatitis B model and conclude that the dependance of the probability of carriage development  (q(Λ)) on the force of infection (Λ) is the main reason for multiple endemicity. Other factors such as a large proportion of infants that are not vaccinated (ω) may also enhance the possibility of multiple endemicity. The role of carriers may also play a key role in the possibility of such complex dynamics, i.e., when infectiousness of carriers-(α) is high, the probability of existence of multiple endemic equilibrium solutions is increased. In our arguments, the traditional reproduction number R0< 1 which we define here by a function G(0) < 1 does not imply stability of disease-free equilibrium.

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