Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 49 )

2018 ( 317 )

2017 ( 289 )

2016 ( 454 )

Custom range...

Search Results: 1 - 10 of 297378 matches for " J.Okello-Onen "
All listed articles are free for downloading (OA Articles)
Page 1 /297378
Display every page Item
The prevalence of serum antibodies to tick-borne infections in Mbale District, Uganda: The effect of agro-ecological zone, grazing management and age of cattle
C. Rubaire-Akiiki,J.Okello-Onen,G.W. Nasinyama,M. Vaarst
Journal of Insect Science , 2004,
Abstract: Between August and October 2000, a cross-sectional study was conducted in smallholder dairy farms in Mbale District, Uganda to assess the prevalence of ticks and tick-borne diseases under different grazing systems and agro-ecological zones and understand the circumstances under which farmers operated. A questionnaire was administered to obtain information on dairy farm circumstances and practices. A total of 102 farms were visited and sera and ticks were collected from 478 animals. Sero-prevalence of tick-borne diseases was determined using an enzyme-linked immunoassay. Acaricides were used indiscriminately but the intensity of their use varied with the grazing system and zone. Cattle from different farms mixed for various reasons. During the dry seasons farmers have to get additional fodder from outside their farms that can result in importation of ticks. The prevalence of ticks and serum antibodies to tick-borne infections differed across the grazing systems and zones. The highest serum antibody prevalence (>60%) was recorded in the lowland zone under the free range and tethering grazing systems. The lowest tick challenge and serum antibody levels (<50%) were recorded in the midland and upland zones under a zero-grazing system. These findings suggest that endemic stability to East Coast Fever, babesiosis and anaplasmosis is most likely to have existed in the lowland zone, particularly, under the tethering and free-range grazing systems. Also, endemic stability for babesiosis existed in the upland zones. Endemic instability for East Coast Fever existed in the midland and upland zones. These structured observational studies are instrumental in planning of control strategies for ticks and tick borne diseases since production systems and the cattle population at high risk of the diseases in the district have been identified.
Endemic stability for Theileria parva infections in Ankole calves of the Ankole ranching scheme, Uganda
F.M. Kivaria,C. Heuer,F. Jongejan,J. Okello-Onen
Onderstepoort Journal of Veterinary Research , 2010, DOI: 10.4102/ojvr.v71i3.259
Abstract: A population-based study was carried out on the Ankole ranching scheme in south-west Uganda with the aim of determining the endemic status of Theileria parva infections. For this purpose, the age-related sero-prevalence of T. parva and the specific calf mortality associated with the parasite were assessed. Blood samples were collected from 931 Ankole calves of up to 12 months of age from 81 randomly selected herds. The relationship between rainfall pattern and whole-body Rhipicephalus appendiculatus counts was determined. The influence of tick control practices on East Coast fever-related calf mortality, and sero-positivity were also determined. A significant (r2 = 0.76, P = 0.000) association between R. appendiculatus counts and rainfall was observed. There was no significant (P > 0.05) association between theileriosis- related calf mortality, sero-positivity and the different tick control practices. Antibody prevalence based on the PIM ELISA was above 70 % among calves of 6 months of age in 96 % in all the herds. Theileria parva-related calf mortality determined by repeated herd visits and farm records ranged between 0% and 5.4 %. It was concluded that endemic stability for theileriosis, caused by T. parva, existed in the study area, and that the risk of the occurrence of economically important outbreaks of East Coast fever in indigenous cattle was regarded as minimal under the prevailing conditions.
Ethnoveterinary Botanicals Used for Tick Control in the Acholi Subregion of Uganda
Robert Opiro,Anne M. Akol,Joseph Okello-Onen
Journal of Animal and Veterinary Advances , 2012, DOI: 10.3923/javaa.2010.2951.2954
Abstract: A survey was done to document ethnobotanicals for managing and controlling tick vectors of deadly cattle diseases. About 100 respondents aged 45 years and more distributed among 10 sub-counties of Gulu and Amuru districts in Northern Uganda were interviewed for their knowledge of plants with anti-tick properties and/or plant species used to manage ticks on cattle. All respondents were drawn from cattle keeping households. The plants were documented in both local and scientific names. A total of 13 plant species falling into 8 different botanical families were documented as locally known to control ticks. A mechanism for propagating these ethnoknowledge as well as conservation measures particularly for the plant species with high use frequency as reported by the locals therefore need to be developed.
Prevalence and Severity of Current Human-Elephant Conflicts in Amboseli Ecosystem, Kenya: Insights from the Field and Key Informants  [PDF]
Moses Makonjio Okello, Stephen J. Njumbi, John Warui Kiringe, James Isiiche
Natural Resources (NR) , 2014, DOI: 10.4236/nr.2014.59043
Few animals elicit such drastically different human emotions, so do elephants. Elephants capture the affection of people but also inspire animosity and fear at the same time. This is because there are conflicts with people over space, critical resources, costs of damages and general insecurity to people. This paper examined field evidence and interviewed expert key informants on current intensity and frequency of human-elephants in Amboseli Ecosystem. According to them, generally, the most prevalent (score of 1 lowest to 10 highest) threats to elephants were competition for critical resources (6.32 ± 0.44) followed by blocking of migration (6.24 ± 0.46), harassment of elephants (4.83 ± 0.75), poaching (4.57 ± 0.37), and retaliatory killings (3.78 ± 0.31). For threats that elephants pose to people, the most prevalent one was crop raiding (6.95 ± 0.26) followed by environmental degradation (6.71 ± 0.46), general insecurity to people (5.76 ± 0.65), property destruction (5.16 ± 0.41), injury and death to livestock (3.78 ± 0.37), and injury and death to people (2.71 ± 0.27). For the severity of the threats, the highest score was given to crop raiding whose average score was 7.90 ± 0.24 followed by environmental destruction and degradation (6.89 ± 0.43), injury and death to people (6.72 ± 0.44), injury and death to livestock (6.36 ± 0.50), property destruction (5.78 ± 0.49), general insecurity to people (5.62 ± 0.64). Severity levels followed the same trend or varied slightly. These drivers of human-elephant conflicts need to be addressed decisively to protect both people and elephants. There is a need to ensure local people’s benefit from elephants through ecotourism investments such as wildlife sanctuaries, leasing critical space for elephants’ dispersal on acceptable terms, through appropriate compensation schemes for elephant costs, and supporting local community wildlife rangers to prevent conflicts.
Depression and Its Relationship to Work Status and Income among HIV Clients in Uganda  [PDF]
Glenn J. Wagner, Bonnie Ghosh-Dastidar, Dickens Akena, Noeline Nakasujja, Elialilia Okello, Emmanuel Luyirika, Seggane Musisi
World Journal of AIDS (WJA) , 2012, DOI: 10.4236/wja.2012.23018
Abstract: Purpose: Despite high levels of depression among persons living with HIV (PLWHIV), little research has investigated the relationship of depression to work status and income in PLWHIV in sub-Saharan Africa, which was the focus of this analysis. Methods: Baseline data from a prospective longitudinal cohort of 798 HIV patients starting antiretroviral therapy in Kampala, Uganda were examined. In separate multivariate analyses, we examined whether depressive severity and symptom type [as measured by the Patient Health Questionnaire (PHQ-9)] and major depression [diagnosed with the Mini International Neuropsychiatric Interview (MINI)] were associated with work status and income, controlling for demographics, physical health functioning, work self-efficacy, social support and internalized HIV stigma. Results: 14% of the sample had Major Depression and 66% were currently working. Each measure of depression (PHQ-9 total score, somatic and cognitive subscales; Major Depression diagnosis) was associated with not working and lower average weekly income in bivariate analysis. However, none of the depression measures remained associated with work and income in multivariate analyses that controlled for other variables associated with these economic outcomes. Conclusions: These findings suggest that while depression is related to work and income, its influence may only be indirect through its relationship to other factors such as work self-efficacy and physical health functioning.
Depression, Internalized HIV Stigma and HIV Disclosure  [PDF]
Elialilia S. Okello, Glenn J. Wagner, Bonnie Ghosh-Dastidar, Jeffrey Garnett, Dickens Akena, Noeline Nakasujja, Seggane Musisi
World Journal of AIDS (WJA) , 2015, DOI: 10.4236/wja.2015.51004
Abstract: Purpose: There is extensive evidence regarding the relationship between HIV related stigma and disclosure; however, the influence of depression in this relationship is not well understood, and thus is the focus of our analysis. Methods: Baseline data from a prospective longitudinal cohort of 798 HIV patients starting ART in Kampala, Uganda were examined. A staged-approach regression analysis was used to examine variables associated with HIV disclosure to most people (general disclosure) and disclosure to primary sex partner. Internalized HIV stigma plus demographic and background covariates were first entered into the model; the binary indicator of clinical depression was added on step two, followed by the addition of the interaction of stigma and depression in step three. Separate analyses were conducted for each of the two disclosure outcomes. Results: 39% indicated that they kept their HIV status as a secret from most people, while 19% of respondents with a regular sex partner had not disclosed their HIV status to the partner. In bivariate analysis, respondents who preferred to keep their HIV status as a secret from most people had higher internalized HIV stigma (p < 0.001) and depression (p < 0.01), and were more likely to be clinically depressed (p < 0.01) compared with others in the sample. Similarly, participants who had not disclosed their HIV status to their main sex partner had higher internalized HIV stigma (p < 0.01) and depression (p < 0.05), and were more likely to be clinically depressed (p < 0.01) compared with those who had informed their partner of their HIV status. The regression analysis revealed that internalized HIV stigma was strongly negatively correlated with disclosure to primary partner, while depression was not associated. In the regression analysis for general disclosure, both stigma and depression were negatively correlated with disclosure when the interaction term was included in the model. Further analysis showed that internalized HIV stigma was more strongly associated with general disclosure among participants who were not depressed. Conclusions: Although there was clearly a strong and consistent association between internalized HIV stigma and depression symptoms, the strong association between internalized HIV stigma and general disclosure among respondents who were not depressed indicated that HIV stigma was in itself remained a strong barrier to HIV disclosure. Therefore, interventions to reduce internalized HIV stigma may aid in efforts to decrease secondary transmission of HIV.
Evaluation of Real-Time 16S rDNA PCR and Pyrosequencing for Routine Identification of Bacteria in Joint Fluid and Tissue Specimens  [PDF]
Naomi J. Gadsby, Alev Onen, Sally-Anne Phillips, Luke Tysall, Steffen J. Breusch, Hamish Simpson, Jayshree Dave, Elzbieta Czarniak, Kate E. Templeton
Open Journal of Medical Microbiology (OJMM) , 2011, DOI: 10.4236/ojmm.2011.11001
Abstract: 16S rDNA PCR and sequencing are powerful tools for bacterial detection and identification, although their routine use is not currently widespread in the field of clinical microbiology. The availability of pyrosequencing now makes 16S rDNA assays more accessible to routine diagnostic laboratories, but this approach has had limited evaluation in general diagnostic practice. In this study we evaluated a real-time 16S rDNA PCR and pyrosequencing assay for use in a routine microbiology laboratory, by retrospectively testing joint fluid and joint tissue specimens received for conventional culture. We found that use of the real-time 16S rDNA assay was clinically valuable in this specimen type because it enabled us to identify a small number of culture-negative infections. Although faster and less labour-intensive, we found that the utility of pyrosequencing for pathogen identification is still hampered by shorter read lengths compared to conventional (Sanger) sequencing. Combining results from both molecular and conventional culture methods, bacteria were only detected in 11.8% specimens in this study. However, the detection rate was increased to 18.6% if specimens were only included from patients with a documented clinical suspicion of infection. In conclusion, while pyrosequencing had significant advantages in speed and ease-of-use over conventional sequencing, multiple reactions will be required to deliver comparable species-level identification, thus negating many of the benefits of using the technique. We found that 16S rDNA PCR and sequencing should be rationally targeted on the basis of good clinical information in the routine diagnostic setting, and not used as a general screening test for the exclusion of bacterial infection in joint specimens.
Factors Influencing Awareness and Use of Electronic – Based Market Information Services for Farming Business in Malawi
Julius J. Okello,Samson P. Katengeza,Edouard R. Mensah
International Journal of Economics and Research , 2011,
Abstract: The government of Malawi has over the years initiated a number of agricultural market interventions including the recent electronic-based market information services in order to expose smallholder farmers to the exigency of market forces. The performance of agricultural markets is of significant importance in Malawi where agriculture remains the engine of growth. The study uses biprobit regression to examine drivers of awareness and adoption of electronic-based market information service interventions for farming business in Malawi. Using capability approach, it poses the hypothesis that farmers’ awareness of ICT-based market information services determines use. Results indicate that household’s awareness is positively influenced by owning a mobile phone, leasing some land and being a member of farmer group while being males, distant to agricultural field office and distance to the nearest electricity center are associated with lower likelihood of being aware. The paper also confirms that awareness raises use of ICT-based market interventions. In fact, drivers of ICT usage include income, membership in farmer group and awareness which interacts with distance to the nearest electricity center, distance to agricultural field office and land size. The study concludes that policy-makers will be valuable to work on formation of farmer organizations, access to power grid and land policy to create an enabling environment for awareness of electronic-based market interventions and ICT usage by farmers in Malawi.
Exit, voice and loyalty in Kenya’s French bean industry: What lessons can we learn from smallholder farmers’ past response to international food safety standards?
JJ Okello
African Journal of Food, Agriculture, Nutrition and Development , 2011,
Abstract: Kenya is one of the leading exporters of fresh vegetables to Europe. Kenyan exporters have since the 1990s targeted the leading European supermarkets with their produce. However, the food safety scandals of the 1980s and 1990s led these supermarkets to adopt stringent food safety protocols relating to pesticide use, hygiene, and traceability. These standards were then passed on to Kenyan exporters. In turn, many leading fresh export companies in Kenya developed their own stringent private protocols relating to food safety standards. Others adopted the European Retail Group’s Good Agricultural Practices or their European buyers’ private food safety standards. In both cases, Kenyan exporters required full compliance with the food safety standards in order to continue buying beans from their suppliers. This study examined how Kenyan smallholder growers responded to the standards and how their response affected their continued participation in the supermarket business. It applies Hirschman’s concept of exit, voice and loyalty to assess the strategies used by Kenyan smallholder French bean farmers in response to international food safety standards (IFSS). It then assesses the factors that influence the success or failure of such strategies. Data obtained in this study suggest that smallholder farmers used different strategies to respond to IFSS. The initial overwhelming response was to exit production. Other farmers resorted to voice strategy: complaints, petitions, threats,lobbying, in attempt to influence buyers/exporters to relax or change the standards. Such farmers largely failed. The rest of the farmers, however, proactively complied with the standards by using collective action and were able to stay in the fresh export business. This strategy of compliance with IFSS has since become the model in smallholder export horticulture in Kenya. This study, therefore, demonstrates role that collective action and proactive response to standards can play in maintaining their participation of smallholder in fresh vegetable export business and suggests the need for assisting the poor smallholder farmers to keep their share of market.
Asynchronous Realization of Algebraic Integer-Based 2D DCT Using Achronix Speedster SPD60 FPGA
Nilanka Rajapaksha,Amila Edirisuriya,Arjuna Madanayake,Renato J. Cintra,Dennis Onen,Ihab Amer,Vassil S. Dimitrov
Journal of Electrical and Computer Engineering , 2013, DOI: 10.1155/2013/834793
Abstract: Transformation and quantization play a critical role in video codecs. Recently proposed algebraic-integer-(AI-) based discrete cosine transform (DCT) algorithms are analyzed in the presence of quantization, using the High Efficiency Video Coding (HEVC) standard. AI DCT is implemented and tested on asynchronous quasi delay-insensitive logic, using Achronix SPD60 field programmable gate array (FPGA), which leads to lower complexity, higher speed of operation, and insensitivity to process-voltage-temperature variations. Performance of AI DCT with HEVC is measured in terms of the accuracy of the transform coefficients and the overall rate-distortion (R-D) characteristics, using HM 7.1 reference software. Results indicate a 31% improvement over the integer DCT in the number of transform coefficients having error within 1%. The performance of the 65?nm asynchronous hardware in terms of speed of operation is investigated and compared with the 65?nm synchronous Xilinx FPGA. Considering word lengths of 5 and 6 bits, a speed increase of 230% and 199% is observed, respectively. These results indicate that AI DCT can be potentially utilized in HEVC for applications demanding high accuracy as well as high throughput. However, novel quantization schemes are required to allow the accuracy improvements obtained. 1. Introduction High dynamic range (HDR) video and image transmission over digital communication channels is undergoing exponential growth [1]. With the increasing demand for high-definition programming, there exists a strong need for efficient digital video coding (DVC) that provides high data compression ratios which in turn leads to better utilization of network resources [2]. The H.264/AVC standard [3] does not provide the required compression ratios for emerging capture and display technologies such as ultra high definition (UHD) [4], multiview [5], and autostereoscopy [6]. To address such emerging needs, the Joint Collaborative Team on Video Coding (JCT-VC) has developed the successor for H.264/AVC, called High Efficiency Video Coding (HEVC) [4]. The HEVC standard aims at achieving a 50% reduction in data rate compared with its predecessors while maintaining low complexity computation. Video compression systems operating at high frequencies and resolutions require hardware capable of significant throughput with tolerable area and power requirements. Real-time video compression circuits having high numerical accuracy are needed for next-generation video [1], coding systems [2, 3, 7], and retina displays [8]. The two-dimensional (2D) 8 8 discrete cosine
Page 1 /297378
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.