Evaluation of genetic diversity in barley (Hordeum vulgare L.) from Wollo high land areas using agromorphological traits and hordein

This study aimed to determine the genetic diversity and relationships among barley varieties (Hordeum vulgare L.) growing at Wollo Highland areas by using hordein and agro-morphological traits. Twenty (20) varieties were laid down in randomized complete block design (RCBD) design with three replications; they were planted by irrigation at Wollo University, Dessie Campus from January to May 2014. The genetic analysis using hordein was done in the laboratory of Ethiopian Biodiversity Institute (EBI) in July 2014. Ten (10) competitive random plants from the rows of the experimental plots were taken for recording their agromorphological characters. Electrophoretic separation of barley storage proteins or hordeins was done using acid polyacrylamide gel electrophoresis (A-PAGE). The traits: day of heading, day of maturity, grain yield (kg/ha), plant height, spike length, number of spiklet per spike, kernel number per spike, weight of seed per spike and biomass yield (g/plot) were highly significant for the diversity of barely, whereas thousand seed weight was less significant. The results reveal positive correlation between spike length and number of spiklet per spike (the highest correlations from the agro morphological traits); the next highly correlated traits were kernel weight per spike and thousand seed weight. The A-PAGE analysis showed limited variation among the analysed accessions. The Nei’s genetic distance for all varieties of barely varied from 0.0000 to 1.6094. It is found that the 20 genotypes of barely investigated in this research were having a gene diversity (h) of overall populations (0.138) using hordein. The cluster analysis grouped the 20 barely genotypes into three different clusters using agro-morphological traits and into four clusters using hordein. This indicates the presence of wide diversity among the tested genotypes. From cluster mean values of agro-morphological traits, genotypes in cluster III deserve consideration for directly developing high yielding barely varieties. The result of the principal components analysis revealed that the first three principal components having greater than 1 eigenvalue contributed 84.22% of the total variation. From this study, it can be concluded that the presence of high morphological variation indicated the potential of Wollo Highland areas in contributing to barley improvement and conservation activities of land areas.Key words: Acid polyacrylamide gel electrophoresis, agro-morphological traits, hordein, genetic distance, hordeum vulgare, variability

Impact of modern agricultural technologies on smallholder welfare: Evidence from Tanzania and Ethiopia

This paper evaluates the potential impact of adoption of improved legume technologies on rural household welfare measured by consumption expenditure in rural Ethiopia and Tanzania. The study utilizes cross-sectional farm household level data collected in 2008 from a randomly selected sample of 1313 households (700 in Ethiopia and 613 in Tanzania). The causal impact of technology adoption is estimated by utilizing endogenous switching regression. This helps us estimate the true welfare effect of technology adoption by controlling for the role of selection problem on production and adoption decisions. Our analysis reveals that adoption of improved agricultural technologies has a significant positive impact consumption expenditure (in per adult equivalent terms) in rural Ethiopia and Tanzania. This confirms the potential role of technology adoption in improving rural household welfare as higher consumption expenditure from improved technologies translate into lower poverty, higher food security and greater ability to withstand risk. An analysis of the determinants of adoption highlighted inadequate local supply of seed, access to information and perception about the new cultivars as key constraints for technology adoption

Agricultural technology adoption, seed access constraints and commercialization in Ethiopia

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

Coupled dynamics of voltage and calcium in paced cardiac cells

We investigate numerically and analytically the coupled dynamics of transmembrane voltage and intracellular calcium cycling in paced cardiac cells using a detailed physiological model and its reduction to a three-dimensional discrete map. The results provide a theoretical framework to interpret various experimentally observed modes of instability ranging from electromechanically concordant and discordant alternans to quasiperiodic oscillations of voltage and calcium

Localization of a polymer in random media: Relation to the localization of a quantum particle

In this paper we consider in detail the connection between the problem of a polymer in a random medium and that of a quantum particle in a random potential. We are interested in a system of finite volume where the polymer is known to be {\it localized} inside a low minimum of the potential. We show how the end-to-end distance of a polymer which is free to move can be obtained from the density of states of the quantum particle using extreme value statistics. We give a physical interpretation to the recently discovered one-step replica-symmetry-breaking solution for the polymer (Phys. Rev. E{\bf 61}, 1729 (2000)) in terms of the statistics of localized tail states. Numerical solutions of the variational equations for chains of different length are performed and compared with quenched averages computed directly by using the eigenfunctions and eigenenergies of the Schr\"odinger equation for a particle in a one-dimensional random potential. The quantities investigated are the radius of gyration of a free gaussian chain, its mean square distance from the origin and the end-to-end distance of a tethered chain. The probability distribution for the position of the chain is also investigated. The glassiness of the system is explained and is estimated from the variance of the measured quantities.Comment: RevTex, 44 pages, 13 figure

Determinants of Agricultural Technology adoption: the case of improved groundnut varieties in Malawi

This paper applies the Average Treatment Effect (ATE) framework on data obtained from a random cross-section sample of 594 farmers in Malawi to document the actual and potential adoption rates of improved groundnut varieties and their determinants conditional on farmers’ awareness of the technology. The fact that not all farmers are exposed to the new technologies makes it difficult to obtain consistent estimates of population adoption rates and their determinants using direct sample estimates and classical adoption models such as probit or tobit. Our approach tries to control for exposure and selection bias in assessing the adoption rate of technology and its determinants. Results indicate that only 26% of the sampled farmers grew at least one of the improved groundnut varieties. The potential adoption rate of improved groundnut for the population is estimated at 37% and the adoption gap resulting from the incomplete exposure of the population to the improved groundnut is 12%. We further find that the awareness of improved varieties is mainly influenced by information access variables, while adoption is largely influenced by economic constraints. The findings are indicative of the relatively large unmet demand for improved groundnut varieties suggesting that there is scope for increasing the adoption rate of improved groundnut varieties in Malawi once the farmers are made aware of the technologies and if other constraints such as lack of access to credit are addressed

Socio-economic Assessment of Legume Production, Farmer Technology Choice,Market Linkages, Institutions and Poverty in Rural Ethiopia: Institutions, Markets, Policy and Impacts Research Report No. 3

Today, about 1.1 billion people continue to live in extreme poverty on less than US$1 a day. Another 1.6 billion live on between US$1–2 per day. Three out of four poor people in developing countries lived in rural areas in 2002 (WDR 2008). Most depend on agriculture for their livelihoods, directly or indirectly. In much of sub-Saharan Africa, agriculture offers a promising opportunity for spurring growth, overcoming poverty, and enhancing food security. Of the total population of sub-Saharan Africa in 2003, 66% lived in rural areas. More than 90% of rural people in these regions depend on agriculture for their livelihoods. Ryan and Spencer (2001) estimated that three-quarters of the 1.3 billion people living below the poverty line in developing countries lived in rural areas. Of these, an estimated 66% relied on marginal lands (TAC 1997). Broad-based agricultural development through improving the productivity, profi tability and sustainability of smallholder farming is the main pathway out of poverty for millions of poor farm households. Agricultural productivity growth is also vital for stimulating growth in other sectors of the economy. But accelerated growth requires a sharp productivity increase in smallholder farming combined with more effective support to the millions coping as subsistence farmers, many of them in marginal areas. Gallup and Sachs (2000) estimated that, in comparison to temperate regions, productivity was 27% lower in the humid tropics and 42% lower in the dry tropics

Determinants of Agricultural Technology adoption: the Case of Improved Pigeonpea Varieties in Tanzania

If dryland legumes are to meet the expectations of reducing poverty and hunger in the semi-arid tropics, there will be need for a full understanding of their potential for diffusion and the barriers to adoption. We apply a program evaluation technique to data obtained from Tanzania to derive estimates of the actual and potential adoption rates of improved pigeonpea varieties and their determinants. The study reveals that only 33% of the sampled farmers were aware of the improved pigeonpea varieties which consequently restricted the sample adoption rate of improved varieties to only 19%. The potential adoption rate of improved pigeonpea if all farmers had been exposed to improved varieties is estimated at 62% and the adoption gap resulting from the incomplete exposure of the population to the improved pigeonpea is 43%. We further find that the awareness of improved varieties is mainly influenced by attendance of Participatory Variety Selection activities. The adoption of improved varieties is more pronounced among farmers with smaller landholdings suggesting that farmers facing land pressure intensify pigeonpea production through the adoption of improved high yielding varieties. The findings are indicative of the relatively large demand for improved pigeonpea varieties suggesting that there is scope for increasing their adoption rate in Tanzania once the farmers are made aware of the existence of the technologies

Early and efficient detection of Mycobacterium tuberculosis in sputum by microscopic observation of broth cultures.

Early, efficient and inexpensive methods for the detection of pulmonary tuberculosis are urgently needed for effective patient management as well as to interrupt transmission. These methods to detect M. tuberculosis in a timely and affordable way are not yet widely available in resource-limited settings. In a developing-country setting, we prospectively evaluated two methods for culturing and detecting M. tuberculosis in sputum. Sputum samples were cultured in liquid assay (micro broth culture) in microplate wells and growth was detected by microscopic observation, or in Löwenstein-Jensen (LJ) solid media where growth was detected by visual inspection for colonies. Sputum samples were collected from 321 tuberculosis (TB) suspects attending Bugando Medical Centre, in Mwanza, Tanzania, and were cultured in parallel. Pulmonary tuberculosis cases were diagnosed using the American Thoracic Society diagnostic standards. There were a total of 200 (62.3%) pulmonary tuberculosis cases. Liquid assay with microscopic detection detected a significantly higher proportion of cases than LJ solid culture: 89.0% (95% confidence interval [CI], 84.7% to 93.3%) versus 77.0% (95% CI, 71.2% to 82.8%) (p = 0.0007). The median turn around time to diagnose tuberculosis was significantly shorter for micro broth culture than for the LJ solid culture, 9 days (interquartile range [IQR] 7-13), versus 21 days (IQR 14-28) (p<0.0001). The cost for micro broth culture (labor inclusive) in our study was US $4.56 per sample, versus US$11.35 per sample for the LJ solid culture. The liquid assay (micro broth culture) is an early, feasible, and inexpensive method for detection of pulmonary tuberculosis in resource limited settings

Spatial distribution of podoconiosis in relation to environmental factors in Ethiopia: a historical review

BACKGROUND An up-to-date and reliable map of podoconiosis is needed to design geographically targeted and cost-effective intervention in Ethiopia. Identifying the ecological correlates of the distribution of podoconiosis is the first step for distribution and risk maps. The objective of this study was to investigate the spatial distribution and ecological correlates of podoconiosis using historical and contemporary survey data. METHODS Data on the observed prevalence of podoconiosis were abstracted from published and unpublished literature into a standardized database, according to strict inclusion and exclusion criteria. In total, 10 studies conducted between 1969 and 2012 were included, and data were available for 401,674 individuals older than 15 years of age from 229 locations. A range of high resolution environmental factors were investigated to determine their association with podoconiosis prevalence, using logistic regression. RESULTS The prevalence of podoconiosis in Ethiopia was estimated at 3.4% (95% CI 3.3%-3.4%) with marked regional variation. We identified significant associations between mean annual Land Surface Temperature (LST), mean annual precipitation, topography of the land and fine soil texture and high prevalence of podoconiosis. The derived maps indicate both widespread occurrence of podoconiosis and a marked variability in prevalence of podoconiosis, with prevalence typically highest at altitudes >1500 m above sea level (masl), with >1500 mm annual rainfall and mean annual LST of 19-21°C. No (or very little) podoconiosis occurred at altitudes 24°C. CONCLUSION Podoconiosis remains a public health problem in Ethiopia over considerable areas of the country, but exhibits marked geographical variation associated in part with key environmental factors. This is work in progress and the results presented here will be refined in future work