Seed filling and oil accumulation in noug [Guizotia abyssinica (L.F.) Cass.]

A field experiment was carried out to study the pattern, rate and duration of seed dry weight (SDW) and oil accumulation in two improved noug varieties during 1995 and 1996. Seeds from uniformly flowered heads were harvested manually seven days after anthesis initiation (DAAI) and continued for 60 days with four days interval. Thousand seed weight and percent oil content were determined for each harvest. The study shows that the extended reproductive period in noug could be well shortened by selecting plants with determinate or semi-determinate growth habit without affecting seed and oil yield. Plants with determinate or semi-determinate growth habit are, hence, morphological ideotypes to look for in noug improvement. Key words/phrases: Guizotia abyssinica, oil accumulation, noug, seed dry weight accumulation SINET: Ethiopian Journal of Science Vol.27(1) 2004: 25-3

Overview study on challenges of additive manufacturing for a healthcare application

Additive manufacturing is a rapidly evolving manufacturing technology bringing numerous and wide opportunities for the design team involved in the process by creating intricate and customized products with saving labor, time, and other expenses. Innovative AM methods and numerous practical applications in aerospace, automotive, medical, energy, and other industries have been developed and commercialized through extensive research over the last two decades. One embraced industry among others that benefited from the advances of AM is the healthcare industry. This paper focuses on addressing the challenges and opportunities in Additive manufacturing for healthcare. Although there are advanced possibilities in AM, there are also numerous issues needed to be overcome. The paper is based upon the current state-of-the-art review and study visits. The purpose of this work has been to identify the opportunities and limitations associated with additive manufacturing in healthcare applications and to highlight the identified research needs

Overview study on challenges of additive manufacturing for a healthcare application

Additive manufacturing is a rapidly evolving manufacturing technology bringing numerous and wide opportunities for the design team involved in the process by creating intricate and customized products with saving labor, time, and other expenses. Innovative AM methods and numerous practical applications in aerospace, automotive, medical, energy, and other industries have been developed and commercialized through extensive research over the last two decades. One embraced industry among others that benefited from the advances of AM is the healthcare industry. This paper focuses on addressing the challenges and opportunities in Additive manufacturing for healthcare. Although there are advanced possibilities in AM, there are also numerous issues needed to be overcome. The paper is based upon the current state-of-the-art review and study visits. The purpose of this work has been to identify the opportunities and limitations associated with additive manufacturing in healthcare applications and to highlight the identified research needs.publishedVersio

AMMI analysis of yields and oil content in some linseed (Linum usitatissimum L.) genotypes in south and central Ethiopia

Linseed (Linum usitatissimum L.) is important to the Ethiopian farmers in terms of its various home uses generating potential in both domestic and foreign markets. One of the major linseed production constraints in the country is the lack of high yielding and high oil content varieties. This experiment was conducted at Hossaina, Kokate, Dida-Midore and Holeta to assess the genotype-by-environment interaction (GEI) among the varieties for yield and oil content. The experiment was carried out using nine released out and three pipeline varieties with a local cultivar. The analysis of variance of AMMI exhibited a very highly significant (P ≤ 0.001) variation due to varieties and locations for grain yield, oil content and oil yield, but GEI was significant for oil content and oil yield and not for grain yield indicating that the stability of the genotypes over the range of locations tested. The genotypes CI-1652, Tolle, Kassa-2, CI-1525, Jeldu, and Kulumsa-1 for oil content and the genotypes Kassa-2, Jeldu and CI-1525 for oil yield formed the first adaptive group with high mean and IPCA1 closer to zero IPCA1 indicating that they were the most stable and had wider adaptability across the studied environments. The AMMI selections for oil content and yield per environment included Kassa-2 in all the four locations; Jeldu in Holeta and Kokate; Kulumsa-1 in Dida-Midore, Hossaina and Kokate; CI-1525 in Holeta and Hossaina; Dibannee in Hossaina for both oil content and oil yield but in Kokate only for oil yield

Analysis of genetic diversity in linseed using AFLP markers

Linseed (Linum usitatissimum L.) is the second most important oilseed crop in the highlands of Ethiopia where it has been cultivated for its valuable seed-oil since antiquity. Sixty accessions of linseed predominantly from Ethiopia were analysed using amplified fragment length polymorphism (AFLP) markers to assess their genetic diversity. Out of seven pairs of AFLP primers screened, Eco-ACA/ Mse-CAT and Eco-ACA/ Mse-CTT resulted in a greater number of amplification products. The estimated genetic distance for pairwise accessions significantly (P < 0.001) varied from 0.29 to 0.71, indicating the prevalence of genetic diversity in both exotic and local collections. Introductions from Canada and collections from different parts of Ethiopia, especially those from central and northwest regions revealed considerable variations between and within their geographic locations and thus can be used to create genetic variations. Cluster analysis categorized the 60 accessions into 13 classes, each consisting of one to 14 accessions. Two introduced accession were individually clustered, showing their greater divergence. AFLP analysis was found effective in discriminating the accessions and in selecting suitable parents for future genetic improvement. It was also useful for efficient management of genetic resources, eliminating unnecessary duplications. Key words/phrases: AFLP, DNA markers, genetic diversity, linseed SINET: Ethiopian Journal of Science Vol. 28 (1) 2005: 41–5

GENERATION MEANS ANALYSIS FOR SOME QUANTITATIVE TRAITS IN SESAME (SESAMUM INDICUM L.) CROSSES FROM ETHIOPIA

The nature of gene action governing the expression of various traits is very helpful in formulating an effective and sound breeding program. The objective of the present study was to determine the type and magnitude of gene action in sesame using generation means analysis to provide a basis for an evaluation of selection methods for the improvement of sesame. The six basic generations parent 1(P1), parent 2 (P2),  hybrid (F1), F2, back cross 1(BC1) and  back cross (BC2) of five crosses such as cross-1 (EW002 x BG006), cross-2 (Dicho x EW006), cross-3 (EW002 x Dicho), cross-4 (Obsa x Dicho) and cross-5 (EW002 x Obsa) were planted in 2012 and 2013 at Uke trial site of Bako Agricultural Research Center in a randomized complete block design, with three replications. The combined analysis of variance indicated highly significant differences among generations for all the traits in all crosses. Simple additive-dominance model exhibited lack of good fit for all the characters studied in all the crosses, except days to maturity in cross 2. The result of the generation means analysis showed that days to flowering, plant height, branches per plant, and capsules per plant and yield per plant were found to be under the control of additive and non-additive gene effects, coupled with duplicate type of epitasis. Biparental mating followed by selection of desired recombinants from the segregating population is the most applicable breeding methodology for traits under the influence of duplicate type of epitasis. Complementary type of epitasis was only observed for plant height in cross 1 and capsules per plant in cross 3, which appeared to be desirable and would be helpful in further improvement of these traits

Morphometric Analysis and Prioritization of Watersheds for Soil Erosion Management in Upper Gibe Catchment

As morphometric investigation is connected to prioritization of watershed, morphometric analysis has got a significance role in light of soil and water conservation. In this study, an endeavour for the examination of point by point morphometric analyses of sub-basins was accomplished through the measurement of linear and shape parameters by using ArcGIS-9.3 software. Specifically, linear and shape morphometric parameters like stream length, stream order, drainage density, stream frequency, bifurcation ratio, Length of overland flow, basin perimeter, form factor, compactness coefficient, elongation ratio has been considered. The SRTM DEM (30 x 30 m) is processed for the delineation resulting in 61 sub-basins. The morphometric parameters which affect the soil erodibility are considered to organize the sub-basins and relegate positions on the premise of their association with erodibility to get compound parameter (Cp) esteem. Based on the value of Cp the sub-basin with the lowest Cp value was given the highest priority and then categorized the sub-basins into three classes as high, medium and low in terms of priority. Accordingly, high priority zone comprises 11 sub-basins, medium 19 and low 31 sub-basins. The sub-basins which are falling under high priority were a great deal more defenceless to soil disintegration and ought to be given high need for land preservation measures

Triply periodic minimal surfaces based functionally graded biomimetic scaffold fabrication via stereolithography

Triply Periodic Minimal Surfaces (TPMS), a class of intricate mathematical surfaces, have emerged as a promising framework for scaffold design due to their ability to replicate the complex geometries found in biological structures. Four TPMS structures, the Schwarz Diamond (D), Schwarz Primitive (P), Gyroid, and IWP (I-wrapped package) were designed for both uniform and graded density and additively manufactured through Stereolithography based additive manufacturing (AM) techniques using biomedical graded material. Two different mechanical tests, tensile and compression tests were examined on the TPMS structure to study their mechanical properties. The results showed that Schwarz D and IWP TPMS show greater tensile strength for both uniform and graded structures with 18.22 MPa and 14.41 MPa in uniform structures and 9.89 MPa and 9.23 MPa in graded structures of Schwarz D and IWP respectively. Uniform TPMSs show overall tensile strength over the graded TPMS. Compressive properties also show that Schwarz D and IWP TPMS have greater compressive strength in both uniform and graded TPMS, where overall graded structures show better strength over the uniform. Graded Schwarz D observed to have 100.68 MPa, and IWP TPMS has 99.57 MPa, and uniform Schwarz D has 33.94 MPa, whereas IWP TPMS shows 31.82 MPa compressive strength. Results reinforce the structure's suitability for scaffold applications, particularly in contexts demanding robust mechanical integrity. The application of SLA AM with biomedical-graded material strengthens the viability in areas like tissue engineering and regenerative medicine.publishedVersio

Growth Performance and Yield of Nile Tilapia (Oreochromis niloticus (Linnaeus, 1758)) under Different Stocking Densities and Fertilization Scenarios in Earthen Pond Culture

This experiment was conducted to explore the effects of chemical and organic fertilizers at different levels of stocking density on the growth performance and yield of Nile Tilapia (Oreochromis niloticus (Linnaeus, 1758)) in earthen pond culture in southwestern Ethiopian highland located at an altitude of 1700 m above sea level. The ponds were divided into control and treatment with diammonium phosphate (DAP) and poultry manure application at three levels of stocking densities as 1, 2 and 3 fish m-2 in a completely randomized design. All the experimental ponds had two replicates. The fertilizers were applied to the treatment ponds at a rate of 2 g m-2 per week for 150 days. Juveniles with mean initial weight of 20.