540 research outputs found
Genetic diversity in Ethiopian Durum wheat ( Triticum turgidum var durum ) inferred from phenotypic variations
The valorization of genetic diversities of major crops like wheat may help substantially to feed the world Population. Durum heat genotypes consisting of 265 farmers’ varieties (FVs), which have been cultivated for many centuries in Ethiopia, as well as 24 improved varieties (IMVs) have been recently evaluated in northern Ethiopia. The evaluation has been carried out at two different locations for 2 consecutive years to verify the inherited diversity in FVs for important phenological and agronomic traits; with the intention to provide refined information to breeders and genebank managers. As a result of a careful evaluation, a very significant variation was observed between the FVs and IMVs. A large number of the former have demonstrated superior performance to the latter in terms of mean values of the major traits within the stipulated years and locations. The best perform-
ing FV has shown a gain of 20% grain yield over the best IMV. Multivariate analyses revealed that FVs displayed larger genetic diversity than in those IMVs. FVs could therefore be used as donor of useful alleles in durum wheat breeding for improvement of yield per se and other traits of agronomic and phenological importance. The identified stable superior FVs include: 8208, 226834A, 238567, 222426, 226282 could be best candidates for farmers in marginal environments. Genotypes that
have shown stable performance for spatial variation such as 204493A, 214357 and 238567; and temporal variation such as 8208, 208479, 214357 and 226834A could be the best candidates for exploitation in future breeding programs
Molecular detection and phylogenetic analysis of Peste des petits ruminants virus circulating in small ruminants in eastern Amhara region, Ethiopia
Background: Peste des Petits Ruminants (PPR) is a severe, highly infectious and fatal viral disease of small ruminants. Four lineages of PPR virus have been identified globally based on sequence analysis of the nucleoprotein (N) and fusion (F) gene. The aim of this study was to isolate and genetically characterize recently circulating PPR virus in small ruminants in the eastern Amhara region in Ethiopia. A total of 28 anti-mortem samples (gum debris, nasal and ocular swab) were collected from clinically suspicious animals and examined for the presence of PPRV by a one-step RT-PCR assay. Samples positive with RT-PCR were subjected to isolation of the virus which were subsequently genetically characterized by sequencing of the nucleoprotein (N) gene and phylogenetic analysis of PPR virus (PPRV) strains. Results: Of the 28 clinical samples examined, 46.4% were positive with RT-PCR for viral nucleic acid. The PPRV was successfully isolated on CHS-20 cell line with the ovine signaling lymphocyte activation molecule (SLAM) receptor expressed on the cell surface and confirmed with RT-PCR and IFAT assay. The nucleotide sequence and phylogenetic analysis indicated that the PPRV obtained were clustered genetically with Lineage IV isolates of the virus. Conclusion: The successful isolation of the virus and molecular findings of this study confirmed active lineage IV PPRV infections among populations of sheep and goats in eastern Amhara, suggesting risks for potential spread of the disease to currently free areas. Thus, we recommend systematic vaccination to contain outbreaks in affected districts and geographically linked surrounding districts to which the disease could potentially spread due to different epidemiological linkages
High-density molecular characterization and association mapping in Ethiopian durum wheat landraces reveals high diversity and potential for wheat breeding
Durum wheat (Triticum turgidum subsp. durum) is a key crop worldwide, and yet, its improvement and adaptation to emerging environmental threats is made difficult by the limited amount of allelic variation included in its elite pool. New allelic diversity may provide novel loci to international crop breeding through quantitative trait loci (QTL) mapping in unexplored material.
Here, we report the extensive molecular and phenotypic characterization of hundreds of Ethiopian durum wheat landraces and several Ethiopian improved lines. We test 81 587 markers scoring 30 155 single nucleotide polymorphisms and use them to survey the diversity, structure, and genome-specific variation in the panel. We show the uniqueness of Ethiopian germplasm
using a siding collection of Mediterranean durum wheat accessions. We phenotype the Ethiopian panel for ten agronomic traits in two highly diversified Ethiopian environments for two consecutive years and use this information to conduct a genome-wide association study. We identify several loci underpinning agronomic traits of interest, both confirming loci already reported and describing new promising genomic regions. These loci may be efficiently targeted with molecular markers already available to conduct marker-assisted selection in Ethiopian and international wheat. We show that Ethiopian durum wheat represents an important and mostly unexplored source of durum wheat diversity. The panel analysed in this study allows the accumulation of QTL mapping experiments, providing the initial step for a quantitative, methodical exploitation of untapped diversity in producing a better wheat
Parasitological Contamination of Wastewater Irrigated and Raw Manure Fertilized Vegetables in Mekelle City and Its Suburb, Tigray, Ethiopia
Watering of vegetables in developing countries including Ethiopia is done using untreated wastewater and raw manure of domestic animal origin is used as fertilizer. Thus, vegetables are considered to be the principal sources of human infection with bacterial, protozoan and helminth parasites. Therefore, the objective of this study was to evaluate the rate of parasitological contamination of pre-harvest vegetables in Mekelle city and its suburban village, ‘Mariam Dahan’. Pre-harvest vegetables were collected from the field during the dry season, washed using physiological saline solution, allowed to sediment overnight, centrifuged and examined microscopically for infective stages of intestinal parasites. Out of the vegetable samples examined, 32.41% in Mekelle city and 30.49% in ‘Mariam Dahan’, contained at least one parasitic contaminant. Strongyloides stercoralis was most encountered parasitic contaminant in the study areas, followed by, Taenia and Entamoeba spp. Highest rate of parasitic contamination was detected on Swiss chard, that was 45.5 and 41.67% in Mekelle city and ‘Mariam Dahan’, respectively. Occurrence of infective stages of intestinal parasites on wastewater-irrigated vegetables may pose public health hazards to farming communities in the study areas. Therefore, evaluation and surveillance of parasitological quality of vegetables is crucial in an attempt to control vegetable-transmitted parasitic infections.Keywords: Untreated wastewater, Raw manure, Pre-harvest Vegetables, Parasitological contamination, Tigray, Ethiopi
Knowledge, Attitude and Practice (KAP) about Insecticide Treated Net (ITN) usage against Malaria in Kolla Tembien district, Tigray, Ethiopia
Optimal use of insecticide treated nets (ITNs) to prevent malaria in a community depends on vector behavior, mass distribution, knowledge and willingness of people to use the nets. This study was aimed at evaluating knowledge, attitude and practice (KAP) about ITNs at household level in rural sub-distracts of Kolla Tembien. For this purpose, interview questionnaire containing KAP variables were administered to the randomly selected household heads. A total of 368 households
were surveyed, and 70.10 % of the respondents were females. The X number of occupants in the households surveyed was found to be 5.50. However, the X number of ITNs owned by the
households was found to be 1.07. Most of the respondents (82.34%) indicated ITNs prevent malaria through protection from mosquito bites. Seventy six percent of the respondents claimed children 0.05). Out of the 260 nets inspected for usage and physical condition during the survey period, more than 50% were kept in a box or other container in the households. Nets that were graded as clean and very dirty accounted for 25% and 25.77%, respectively. Physical inspection of the randomly sampled nets also revealed holes ranging from those that didn’t allow a thumb to pass through ( X number = 3.47) to those that were wider than a closed fist ( X number = 1.64). The over all knowledge, attitude and practice of ITN usage was found to be satisfactory in the study district. However, the occupant net ratio must be
narrowed and attention needs to be given to malaria vulnerable groups in the household. Continuous monitoring and evaluation of net usage after distribution should be instituted to avoid misuses and associated net damages in the study areas
First experiences with a novel farmer citizen science approach: crowdsourcing participatory variety selection through on-farm triadic comparisons of technologies (TRICOT)
Rapid climatic and socio-economic changes challenge current agricultural R&D capacity. The necessary quantum leap in knowledge generation should build on the innovation capacity of farmers themselves. A novel citizen science methodology, triadic comparisons of technologies or tricot, was implemented in pilot studies in India, East Africa, and Central America. The methodology involves distributing a pool of agricultural technologies in different combinations of three to individual farmers who observe these technologies under farm conditions and compare their performance. Since the combinations of three technologies overlap, statistical methods can piece together the overall performance ranking of the complete pool of technologies. The tricot approach affords wide scaling, as the distribution of trial packages and instruction sessions is relatively easy to execute, farmers do not need to be organized in collaborative groups, and feedback is easy to collect, even by phone. The tricot approach provides interpretable, meaningful results and was widely accepted by farmers. The methodology underwent improvement in data input formats. A number of methodological issues remain: integrating environmental analysis, capturing gender-specific differences, stimulating farmers' motivation, and supporting implementation with an integrated digital platform. Future studies should apply the tricot approach to a wider range of technologies, quantify its potential contribution to climate adaptation, and embed the approach in appropriate institutions and business models, empowering participants and democratizing science
The Jus Ad Bellum and the 1998 Initiation of the Eritrean-Ethopian War
From May 1998 to December 2000, Eritrea and Ethiopia engaged in an armed conflict that cost the lives of thousands of individuals, injured thousands more, and displaced tens of thousands of men, women, and children from their homes. In December 2000, the two sides concluded a comprehensive agreement that ended the war. Among other things, the agreement established the Eritrea-Ethiopia Claims Commission. Consisting of five arbitrators, the Commission’s mandate was to “decide through binding arbitration all claims for loss, damage or injury by one Government against the other” that were “related to the conflict” and that “resulted from violations of international humanitarian law, including the 1949 Geneva Conventions, or other violations of international law.” The two countries filed claims with the Commission in December 2001 and from that time until August 2009, the Commission issued seventeen arbitral awards and eight decisions, covering a broad array of claims, including inhumane treatment of prisoners of war and civilian internees, abuse of enemy aliens in a belligerent’s territory or in occupied territory, wrongful seizure of the enemy’s public or private property, indiscriminate battlefield conduct or aerial bombing, harassment of diplomats and seizure of diplomatic property, and many other matters. The book LITIGATING WAR: ARBITRATION OF CIVIL INJURY BY THE ERITREA-ETHIOPIA CLAIMS COMMISSION seeks to integrate in discrete chapters the Commission’s findings on key topics, with each chapter organized into sub-sections that deal with the principal elements of that topic. The guiding emphasis is not on who-filed-what claim but is instead on what kinds of violations were addressed by the Commission, what kinds of evidence were relevant in establishing or defending against such violations, what legal conclusions emerged in addressing those violations, and what levels of compensation were deemed appropriate when a violation was found.The dominant area of international law upon which claims before the Eritrea-Ethiopia Claims Commission were based was the jus in bello, or the law operating as between two belligerents after an armed conflict has arisen. One type of claim filed before the Commission, however, was quite different, in that it concerned an alleged violation of the jus ad bellum, or the law on when a state may resort to a use of military force against another state. As one of the most important norms for the international legal system, the Commission’s treatment of the jus ad bellum claim is of particular interest, and is addressed in the book’s Chapter IV on “Initiation of War.
Phenotypic Variation and Bistable Switching in Bacteria
Microbial research generally focuses on clonal populations. However, bacterial cells with identical genotypes frequently display different phenotypes under identical conditions. This microbial cell individuality is receiving increasing attention in the literature because of its impact on cellular differentiation, survival under selective conditions, and the interaction of pathogens with their hosts. It is becoming clear that stochasticity in gene expression in conjunction with the architecture of the gene network that underlies the cellular processes can generate phenotypic variation. An important regulatory mechanism is the so-called positive feedback, in which a system reinforces its own response, for instance by stimulating the production of an activator. Bistability is an interesting and relevant phenomenon, in which two distinct subpopulations of cells showing discrete levels of gene expression coexist in a single culture. In this chapter, we address techniques and approaches used to establish phenotypic variation, and relate three well-characterized examples of bistability to the molecular mechanisms that govern these processes, with a focus on positive feedback.
A Fixed Point Theorem in Orbitally Complete Partially Ordered Metric Spaces
Let (X,⪯) be a partially ordered set and T:X→X be a mapping. We prove a fixed point theorem for the map T satisfying a contractive condition in orbits, when X is T-orbitally complete. Our result extends and generalizes the results of Samet et al. (2013) to partially ordered sets. Also, we generalize the results of Ran and Reurings (2004).</jats:p
Central Afar: An analogue for oceanic plateau development
The structure, composition, and evolution of oceanic plateaus are poorly understood and strongly debated. Here, we compared the magmatic history and crustal structure of Afar with the Greenland−Iceland−Faroe Ridge and other oceanic plateaus. Key similarities indicate that Central Afar represents the early stage of development of a specific type of oceanic plateau: a rifted oceanic magmatic plateau (ROMP). These features begin their formation before continental rifting and develop into wide magmatic rift systems capable of isolating slivers of continental crust within the new igneous crust. Importantly, the anomalous magmatism continues through breakup and for several tens of millions of years afterward. The recognition of Central Afar as a precursor of this type of oceanic plateau allows us to better understand their formation. Increased melt production causes early and voluminous magmatism, ultrathick igneous crust, and repeated reorganization of the extension locus during rift/ridge jumps, which delay the onset of oceanization and Penrose-style crustal production. These factors differentiate ROMPs from many magma-rich rifted continental margins and from other types of oceanic plateaus, highlighting that Central Afar and other ROMPs should neither be considered as conventional magma-rich margins nor be considered as normal oceanic crust
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