142 research outputs found
Adoption of a New Maize and Production Efficiency in Western Kenya
Declining yields of maize as a result of Striga infestation has necessitated a new technology known as Imazapyr-resistant maize (IRM) to contain the problem. As a result, research and development initiatives with substantial participation of the private sector to transfer this new technology to farmers have been made in western Kenya. This study therefore assesses the adoption of IRM variety and efficiency levels of farmers in western Kenya. A multi-stage sampling technique was used to select a total of 600 households from Nyanza and Western provinces for this study. Tobit model and stochastic production frontier analysis were the analytical methods. Results show that age, education, maize production gap, risk, contact with extension agents, lack of seeds, membership in social group, effective pathway for IRM dissemination and compatibility of the technology are the variables that were found to be significant (P<0.05) in shaping the decisions of households on whether to adopt or not. The study reveals that the mean technical efficiency of maize production of sampled farmers is 70% indicating some inefficiencies of maize production in western Kenya. Also, adoption of IRM significantly increased frontier maize output (P<0.01); household size decreased inefficiency along with farm size. It was recommended that efforts to increase adoption of IRM for enhanced farm efficiency should focus on farmers’ education, farming experience and access to information and farm basic inputs.IRM technology, efficiency, stochastic production frontier, Tobit model, Crop Production/Industries,
CONTRIBUTIONS OF AGRICULTURAL IMPROVED TECHNOLOGIES TO RURAL POVERTY ALLEVIATION IN DEVELOPING COUNTRIES: CASE OF IMAZAPYR-RESISTANT MAIZE IN WESTERN KENYA
Last two decades have been dominated by issues on poverty as major growth area with the adoption by United Nations member countries of the Millennium Development Goals, the first of which calls for halving the incidence of poverty and hunger by 2015, this has underlined the importance of introduction of improved agricultural technologies. Most poor rural households in developing countries usually depend on agriculture and have to cope with poverty stills a rural phenomenon. Agricultural production has continuously decreased, subject to serious limitations such as declining soil fertility, diseases, pests, drought and erosion plaguing crops growing areas. This situation should have encouraged rural households to increasingly consider the use of promising technologies. This study was done using a case of imazapyr-resistant maize (IRM) technology for combating noxious Striga weed which has devastating effects on maize production in western Kenya. A cross sectional survey that included randomly a total selected sample of 600 households of which 169 IRM users and 431 non-users was employed.IRM technology, striga control, poverty reduction, Kenya., Research and Development/Tech Change/Emerging Technologies,
Assessing the technical efficiency of maize producers with Imazapyrresistant maize for Striga control in Western Kenya
Imazapyr-Resistant Maize (IRM) is a weed control technology, not yet well adopted in the Striga prone area in Western Kenya. The adoption may expand in the future because it enhances maize production via efficiency gains. As to help farmers maximize the maize output affected by Striga for so long in time, research and development initiatives with substantial participation of the private sector to shift to this novel technology have been made in Western Kenya. A multistage random sampling technique was used to select a total of 600 households from Nyanza and Western provinces for this study. Stochastic production frontier analysis was the analytical method and the study revealed that the mean technical efficiency in the maize production sector is 70% indicating some inefficiencies of maize production. Technical inefficiency effects were influenced by household size along with farm size. Enhancing the technical efficiency will increase net returns of maize production enterprises, hence, improving livelihoods of maize producers
Temporal Modulation of Traveling Waves in the Flow Between Rotating Cylinders With Broken Azimuthal Symmetry
The effect of temporal modulation on traveling waves in the flows in two
distinct systems of rotating cylinders, both with broken azimuthal symmetry,
has been investigated. It is shown that by modulating the control parameter at
twice the critical frequency one can excite phase-locked standing waves and
standing-wave-like states which are not allowed when the system is rotationally
symmetric. We also show how previous theoretical results can be extended to
handle patterns such as these, that are periodic in two spatial direction.Comment: 17 pages in LaTeX, 22 figures available as postscript files from
http://www.esam.nwu.edu/riecke/lit/lit.htm
Status of Animal Feed Resources in Rwanda
Animal feed resources remain a major constraint for livestock development in tropical Africa. In Rwanda, grazing lands are shrinking sharply because crop cultivation is progressively encroaching on grazing areas with increasing human pressure (Mutimura and Everson 2011). Therefore, over 60% of households cultivating less than 0.7 ha, and owning livestock, practise zero-grazing, where farmers cut-and-carry forage and crop residues to feed animals that are kept exclusively under sheds (MINAGRI 2009). In general, the main feed for dairy cattle under a zero-grazing system is Napier grass (Pennisetum purpureum). For more than a decade, efforts to improve the feed resource base and feeding management have been based on the introduction, characterisation and evaluation of exotic forage species, including grasses and legumes. The main aim of this study was to identify and document the status of improved forages as animal feed resources and for use in environmental protection in Rwanda
Symptoms and functional limitations related to respiratory health and carbon monoxide poisoning in Tanzania: a cross sectional study
BACKGROUND: The burden of chronic respiratory symptoms and respiratory functional limitations is underestimated in Africa. Few data are available on carbon monoxide (CO) poisoning in sub-Saharan Africa and existing data is derived from CO in ambient air, but not from biomarkers in the blood. METHODS: Data from the Tanzanian Lung Health study, a cross-sectional study on lung health among outpatients and visitors to an urban as well as a rural hospital in Tanzania, was analyzed to describe respiratory symptoms and functional limitations. Saturation of peripheral blood with carbon monoxide (SpCO) was measured transcutaneously and non-invasively in participants using a modified pulse oxymeter indicative of CO poisoning. Univariate and multivariate analysis was performed. RESULTS: Nine hundred and ninety-seven participants were included in the analysis, the median age of participants was 46 years (49% male). 38% of participants reported some degree of chronic shortness of breath and 26% felt limited in their daily activities or at work by this symptom. The median SpCO was 7% (IQR 4-13, range 2-31%) among all participants without active smoking status (N = 808). Participants cooking with gas or electricity had the lowest SpCO (median 5%), followed by participants cooking with charcoal (median 7%). Cooking with wood, particularly using a stove, resulted in highest SpCO (median 11.5%). Participants from households where cooking takes place in a separate room had the lowest SpCO as compared to cooking outside or cooking in a shared room inside (6% vs. 9% vs.10.5%, p < 0.01). Sex or the activity of cooking itself was not associated with a difference in SpCO. Multivariate analysis confirmed cooking in a separate room (as compared to cooking outside) and living in a rural vs. urban setting as protective factors against high SpCO. CONCLUSION: The findings demonstrate a high burden of chronic respiratory symptoms which also cause socioeconomic impact. High levels of SpCO indicate a relevant burden of carbon monoxide poisoning in the local population. The level of CO in the blood is more dependent on shared exposure to sources of CO with the type of housing and type of cooking fuel as most relevant factors, and less on person-individual risk factors or activities
Ring-Pattern Dynamics in Smectic-C* and Smectic-C_A* Freely Suspended Liquid Crystal Films
Ring patterns of concentric 2pi-solitons in molecular orientation, form in
freely suspended chiral smectic-C films in response to an in-plane rotating
electric field. We present measurements of the zero-field relaxation of ring
patterns and of the driven dynamics of ring formation under conditions of
synchronous winding, and a simple model which enables their quantitative
description in low polarization DOBAMBC. In smectic C_A* TFMHPOBC we observe an
odd-even layer number effect, with odd number layer films exhibiting order of
magnitude slower relaxation rates than even layer films. We show that this rate
difference is due to much larger spontaneous polarization in odd number layer
films.Comment: 4 RevTeX pgs, 4 eps figures, submitted to Phys. Rev. Let
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HIV-free survival among nine- to 24-month-old children born to HIV-positive mothers in the Rwandan national PMTCT programme: a community-based household survey
<p>Abstract</p> <p>Background</p> <p>Operational effectiveness of large-scale national programmes for the prevention of mother to child transmission (PMTCT) of HIV in sub-Saharan Africa remains limited. We report on HIV-free survival among nine- to 24-month-old children born to HIV-positive mothers in the national PMTCT programme in Rwanda.</p> <p>Methods</p> <p>We conducted a national representative household survey between February and May 2009. Participants were mothers who had attended antenatal care at least once during their most recent pregnancy, and whose children were aged nine to 24 months. A two-stage stratified (geographic location of PMTCT site, maternal HIV status during pregnancy) cluster sampling was used to select mother-infant pairs to be interviewed during household visits. Alive children born from HIV-positive mothers (HIV-exposed children) were tested for HIV according to routine HIV testing protocol. We calculated HIV-free survival at nine to 24 months. We subsequently determined factors associated with mother to child transmission of HIV, child death and HIV-free survival using logistic regression.</p> <p>Results</p> <p>Out of 1448 HIV-exposed children surveyed, 44 (3.0%) were reported dead by nine months of age. Of the 1340 children alive, 53 (4.0%) tested HIV positive. HIV-free survival was estimated at 91.9% (95% confidence interval: 90.4-93.3%) at nine to 24 months. Adjusting for maternal, child and health system factors, being a member of an association of people living with HIV (adjusted odds ratio: 0.7, 95% CI: 0.1-0.995) improved by 30% HIV-free survival among children, whereas the maternal use of a highly active antiretroviral therapy (HAART) regimen for PMTCT (aOR: 0.6, 95% CI: 0.3-1.07) had a borderline effect.</p> <p>Conclusions</p> <p>HIV-free survival among HIV-exposed children aged nine to 24 months is estimated at 91.9% in Rwanda. The national PMTCT programme could achieve greater impact on child survival by ensuring access to HAART for all HIV-positive pregnant women in need, improving the quality of the programme in rural areas, and strengthening linkages with community-based support systems, including associations of people living with HIV.</p
Under-two child mortality according to maternal HIV status in Rwanda: assessing outcomes within the National PMTCT Program
Introduction: We sought to compare risk of death among children aged under-2 years born to HIV positive mother (HIV-exposed) and to HIV negative mother (HIV non-exposed), and identify determinants of under-2 mortality among the two groups in Rwanda. Methods: In a stratified, two-stage cluster sampling design, we selected mother-child pairs using national Antenatal Care (ANC) registers. Household interview with each mother was conducted to capture socio-demographic data and information related to pregnancy, delivery and post-partum. Data were censored at the date of child death. Using Cox proportional hazard model, we compared the hazard of death among HIV-exposed children and HIV nonexposed children. Results: Of 1,455 HIV-exposed children, 29 (2.0%; 95% CI: 1.3%-2.7%) died by 6 months compared to 18 children of the 1,565 HIV non-exposed children (1.2%; 95% CI: 0.6%-1.7%). By 9 months, cumulative risks of death were 3.0% (95%; CI: 2.2%-3.9%) and 1.3% (96%; CI: 0.7%-1.8%) among HIV-exposed and HIV non-exposed children, respectively. By 2 years, the hazard of death among HIVexposed children was more than 3 times higher (aHR:3.5; 95% CI: 1.8-6.9) among HIV-exposed versus non-exposed children. Risk of death by 9-24 months of age was 50% lower among mothers who attended 4 or more antenatal care (ANC) visits (aHR: 0.5, 95% CI: 0.3-0.9), and 26% lower among families who had more assets (aHR: 0.7, 95% CI: 0.5-1.0). Conclusion: Infant mortality was independent of perinatal HIV exposure among children by 6 months of age. However, HIV-exposed children were 3.5 times more likely to die by 2 years. Fewer antenatal visits, lower household assets and maternal HIV seropositive status were associated with increased mortality by 9-24 months.Key words: HIV, PMTCT, maternal HIV infection, infant mortality, child mortality, under-five mortality, Rwand
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