430 research outputs found

    Screening Some Tef [Eragrostis Tef (Zucc.)Trotter] Accessions/Varieties for Salt Tolerance during Germination and Seedling Stage

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    Salinity is a continuing problem in the arid and semi-arid tracts of the world. It could be alleviated using irrigation management and/or crop management. However, the former approach is outdated and very expensive. Nevertheless, the latter is economical as well as efficient, and it enables to produce salt tolerant crop lines. But prior to that there is a need to confirm the presence of genetic based variation for salt tolerance among different species or varieties of a particular crop that can thrive under unreliable agro-ecological situations; tef [Eragrostis tef (Zucc) Trotter] is one of such crops. Thus fifteen lowland tef genotypes (10 accessions and 5 varieties) were tested during germination and seedling stage at 2dS/m, 4dS/m, 8dS/m, 12dS/m and 16dS/m salinity levels. Distilled water (0dS/m) was used as a control. Data analysis was carried out using SAS package. Germination percentage (GP), germination rate (GR), seedling shoot length (SSL) and seedling root length (SRL) were measured. The analyzed data showed significant variation among most parameters recorded for accessions and varieties (p < 0.01) and for treatments (p < 0.001). Germination rate and seedling root length were more salt affected than final germination percentage and seedling shoot length respectively. The main cause for reduced and delayed germination percentage was osmotic effect. The ion effect was also learned to be minimal. Most accessions and varieties failed to germinate at 12dS/m and 16dS/m salinity levels. Thus, these salt concentrations were not important in screening tef genotypes for salt tolerance. Varieties such as DZ-01-1281, DZ-Cr-358 and accession 236512 were found to be salt sensitive. However, variety DZ-Cr-37 and accessions 237186, 237131 and 212928 were found to be salt tolerant. The rest accessions and varieties were intermediate in their salt tolerance. The study affirmed the presence of broad intraspecific variation among tef accessions and varieties for salt tolerance but more in the former. Key words: Accessions, Germination, NaCl, Salinity, Eragrostis tef

    The African Union, the Transformation and Challenges of a Continent

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    The establishment of the African Union was noteworthy in the way it undermined the authoritarian theory and practice of its predecessor, the Organization of African Unity. The justification was based on the right of peaceful co-existence of member states and—as a consequence—the right of member states to request intervention from the Union in order to restore peace and security. The African Union’s Constitutive Act introduced an array of responsibilities, powers, and rules that challenged the premises of Africa’s earlier leaders. The Act established how the Union would carry out its business through a network of organs, agencies, government ministries, and NGOs, which this paper examines in some detail. While the organizational structure attempted to balance national and continental concerns, it also revealed an obvious weakness in the power of its three principal parliamentary, administrative and legal bodies. Although AU has made great strides in building an institution committed to human security and development, there is need to sharpen its focus, and bring about more specificity in organizational goals. The dual missions of a movement championing the independence of sovereign African states and simultaneously creating a homeland for all of African descent were, if not contradictory, at least so divergent as to strain the ability of its leaders to ensure a lasting consensus. While the initial vision was a powerful one and attracted a group of true believers, the complexities of a modern global economy have demanded an array of new developmental strategies to meet this challenge. The challenges include but not limited to good governance in Africa, alleviation of poverty and hunger, as well as hindrances to citizen participation, especially women, in civic and state affairs. Keywords: AU, OAU, African Transformation, African Challenge

    Lateral phase separation of confined membranes

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    We consider membranes interacting via short, intermediate and long stickers. The effects of the intermediate stickers on the lateral phase separation of the membranes are studied via mean-field approximation. The critical potential depth of the stickers increases in the presence of the intermediate sticker. The lateral phase separation of the membrane thus suppressed by the intermediate stickers. Considering membranes interacting with short and long stickers, the effect of confinement on the phase behavior of the membranes is also investigated analytically

    Brownian motors: current fluctuations and rectification efficiency

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    With this work we investigate an often neglected aspect of Brownian motor transport: The r\^{o}le of fluctuations of the noise-induced current and its consequences for the efficiency of rectifying noise. In doing so, we consider a Brownian inertial motor that is driven by an unbiased monochromatic, time-periodic force and thermal noise. Typically, we find that the asymptotic, time- and noise-averaged transport velocities are small, possessing rather broad velocity fluctuations. This implies a corresponding poor performance for the rectification power. However, for tailored profiles of the ratchet potential and appropriate drive parameters, we can identify a drastic enhancement of the rectification efficiency. This regime is marked by persistent, uni-directional motion of the Brownian motor with few back-turns, only. The corresponding asymmetric velocity distribution is then rather narrow, with a support that predominantly favors only one sign for the velocity.Comment: 9 pages, 4 figure

    The impact of school nutritional campaigns on OFSP adoption and food security among smallholder farming households in Tigray region, Ethiopia.

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    In Ethiopia, the International Potato Center (CIP) and regional partners piloted a 2-year project that promoted production and consumption of vitamin A-rich OFSP as part of diversified diets. The project adopted school-based nutritional campaigns wherein school gardens and school feeding were piloted in 11 schools between 2011 to 2013. The schools served centres for the dissemination of planting material (vines) and transfer of information on benefits of OFSP and its production practices to parents

    COD and colour removal from molasses spent wash using activated carbon produced from bagasse fly ash of Matahara sugar factory, Oromiya region, Ethiopia

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    The aim of this study was to investigate the removal of chemical oxygen demand (COD) and colour from a melanoidin solution using activated carbon produced from bagasse fly ash (BFA). Melanoidins are heterogeneous polymers and major contributors to the dark brown colour of molasses spent wash, which is an extensive cause of environment pollution. The surface area of the BFA was determined as 160.9 +/- 2.8m(2)/g with 90% of particle less than 156.8 mu m in size. Characterization of the BFA by Fourier transform infrared spectroscopy (FTIR) showed the presence of hydroxyl and carbonyl functional groups, whereas X-ray diffraction analysis indicated its amorphous nature. Moreover, scanning electron microscopy analysis showed a heterogeneous and irregular shape of pores. Among the adsorption isotherm models analysed, the Freundlich model fitted best to the experimental data, indicating a maximum adsorptive capacity of 124.80 mg/g. The removal of COD and colour from a melanoidin solution with this activated carbon was carried out using an experimental design taking 4 factors into account. These were adsorbent dose, contact time, pH and initial COD concentration, with removal of COD and colour as response variables. COD reduction was influenced by initial COD concentration whereas colour removal was dominated by contact time, which was in line with the findings of principal component analysis. The maximum COD removal recorded was 61.6% at the optimum condition of adsorbent dose of 4 g in 100 mL, contact time of 4 h, pH 8 and initial COD concentration 6 000 mg/L, whereas the decolourization of melanoidin solution was 64% at adsorbent dose of 4 g, contact time 4 h, pH 3 and initial COD concentration 6 000 mg/L. Hence, activated BFA is a promising option for simultaneous removal of COD and colour from molasses spent wash under the stated conditions

    Thermally induced directed currents in hard rod systems

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    We study the non equilibrium statistical properties of a one dimensional hard-rod fluid undergoing collisions and subject to a spatially non uniform Gaussian heat-bath and periodic potential. The system is able to sustain finite currents when the spatially inhomogeneous heat-bath and the periodic potential profile display an appropriate relative phase shift, ϕ\phi. By comparison with the collisionless limit, we determine the conditions for the most efficient transport among inelastic, elastic and non interacting rods. We show that the situation is complex as, depending on shape of the temperature profile, the current of one system may outperform the others.Comment: 5 pages, 2 figure

    Agricultural technology adoption, seed access constraints and commercialization in Ethiopia

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    This article examines the driving forces behind farmers’ decisions to adopt agricultural technologies and the causal impact of adoption on farmers’ integration into output market using data obtained from a random cross-section sample of 700 farmers in Ethiopia. We estimate a Double-Hurdle model to analyze the determinants of the intensity of technology adoption conditional on overcoming seed access constraints. We estimate the impact of technology adoption on farmers’ integration into output market by utilizing treatment effect model, regression based on propensity score as well as matching techniques to account for heterogeneity in the adoption decision, and for unobservable characteristics of farmers and their farm. Results show that knowledge of existing varieties, perception about the attributes of improved varieties, household wealth (livestock and land) and availability of active labor force are major determinants for adoption of improved technologies. Our results suggest that the adoption of improved agricultural technologies has a significant positive impact on farmers’ integration into output market and the findings are consistent across the three models suggesting the robustness of the results. This confirms the potential direct role of technology adoption on market participation among rural households, as higher productivity from improved technology translates into higher output market integration

    Drought resistance indices for screening of potato (Solanum tuberosum L.) genotypes

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    Open Access JournalIn breeding for drought tolerance, availability of precise, cheap and easy to apply selection tool is critical. The aim of the present study was to identify potential screening tools that are useful for selection of drought tolerant genotypes in potato and select drought resistant potato genotypes. The study assessed sixty clones arranged in a 10×6 alpha lattice design with two replicates in a managed stress experiment. Two irrigation treatments were applied: fully watered non-stress and terminal drought, where the irrigation water supply to the crop was withheld after 50 % flowering to induce post-flowering stress. Stress indices were calculated based on tuber yield of genotypes in both stressed and non-stressed conditions. Identification of drought tolerant genotypes based on a single index was less informative as different indices identified different genotypes as drought tolerant. Hence, to determine the most desirable drought tolerant clones rank sum of indices, correlation, and bi-plot display of the principal component analysis was employed. The indices modified stress tolerance index based on non-stressed yield, Men productivity, Geometric mean productivity, Stress tolerance index, Harmonic mean, modified stress tolerance index based on stressed yield and Yield index exhibited strong association with both yield under stressed and non-stressed yield. These indices discriminated drought tolerant genotypes with higher tuber yielding potential both under stress and non-stress conditions. Genotypes CIP-398180.612, CIP-397069.5, and CIP-304371.67 were identified as drought tolerant. These genotypes could be potentially grown both under drought prone and potential environments and these selection attributes could help to develop climate resilient potato varieties

    Poverty Reduction Effects of Agricultural Technology Adoption: A Micro-evidence from Rural Tanzania

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    This article evaluates the impact of adoption of improved pigeonpea technologies on consumption expenditure and poverty status using cross-sectional data of 613 households from rural Tanzania. Using multiple econometric techniques, we found that adopting improved pigeonpea significantly increases consumption expenditure and reduces poverty. This confirms the potential role of technology adoption in improving household welfare as higher incomes translate into lower poverty. This study supports broader investment in agriculture research to address vital development challenges. Reaching the poor with better technologies however requires policy support for improving extension efforts, access to seeds and market outlets that stimulate adoption
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