Molecular Genetic Diversity Study of Forest Coffee Tree (Coffea arabica L.) Populations in Ethiopia: Implications for Conservation and Breeding

Coffee provides one of the most widely drunk beverages in the world, and is a very important source of foreign exchange income for many countries. Coffea arabica, which contributes over 70 percent of the world's coffee productions, is characterized by a low genetic diversity, attributed to its allopolyploidy origin, reproductive biology and evolution. C. arabica has originated in the southwest rain forests of Ethiopia, where it is grown under four different systems, namely forest coffee, small holders coffee, semi plantation coffee and plantation coffee. Genetic diversity of the forest coffee (C. arabica) gene pool in Ethiopia is being lost at an alarming rate because of habitat destruction (deforestation), competition from other cash crops and replacement by invariable disease resistant coffee cultivars. This study focused on molecular genetic diversity study of forest coffee populations in Ethiopia using PCR based DNA markers such as random amplified polymorphic DNA (RAPD), inverse sequence-tagged repeat (ISTR), inter-simple sequence repeats (ISSR) and simple sequence repeat (SSR) or microsatellites. The objectives of the study are to estimate the extent and distribution of molecular genetic diversity of forest coffee and to design conservation strategies for it’s sustainable use in future coffee breeding. In this study, considerable samples of forest coffee collected from four coffee growing regions (provinces) of Ethiopia were analysed. The results indicate that moderate genetic diversity exists within and among few forest coffee populations, which need due attention from a conservation and breeding point of view. The cluster analysis revealed that most of the samples from the same region (province) were grouped together which could be attributed to presence of substantial gene flow between adjacent populations in each region in the form of young coffee plants through transplantation by man. In addition wild animals such as monkeys also play a significant role in coffee trees gene flow between adjacent populations. The overall variation of the forest coffee is found to reside in few populations from each region. Therefore, considering few populations from each region for either in situ or ex situ conservation may preserve most of the variation within the species. For instance, Welega-2, Ilubabor-2, Jima-2 and Bench Maji-2 populations should be given higher priority. In addition, some populations or genotypes have displayed unique amplification profiles particularly for RAPD and ISTR markers. Whether these unique bands are linked to any of the important agronomic traits and serve in marker assisted selections in future coffee breeding requires further investigations

Community-Level Influences on Early Sexual Initiation in Nigeria

Using national survey data from Nigeria, this study examines individual and community-level determinants of early sexual initiation. Community-level factors exercise important effects on the early onset of sexual initiation. Consistent with the social capital hypothesis, young people living in communities that are more knowledgeable about HIV/AIDS transmission and prevention, communities that are open to receiving HIV/AIDS information, and communities that support condom use as well as family planning are more likely to delay sexual initiation than others. The disadvantages associated with living in a community that is less well informed, less supportive of condom use and less open to receiving information on HIV/AIDS are significantly higher for women. Women who live in communities where attitudes about reproductive health are not positive or where there is lack of social support for condom use are at a heightened risk of early sexual initiation

Eliciting user requirements for ambient intelligent systems: a case study

Ambient intelligent (AmI) systems are electronic environments that are responsive and sensitive to the presence of people (Weiser, 1991). Eliciting requirements for AmI systems, like for any novel technology, is hard because of high uncertainties, such as: 1) both the users and use context are unknown; 2) there is no identified problem that needs to be solved (people cannot state in advance what they want); 3) there is no product idea; 4) it is unclear what future technology can do. There are currently no requirements engineering method for novel AmI technologies. In this short note, we present the current state of our research, which aims at defining a method for identifying requirements for AmI systems

Transonic and supersonic Euler computations of vortex-dominated flow fields about a generic fighter

Flow fields about a generic flighter model were computed using FL057, a 3-D, finite volume Euler code. Computed pressure coefficients, forces, and moments at several Mach numbers (0.6, 0.8, 1.2, 1.4, and 1.6) are compared with wind tunnel data over a wide range of angles of attack in order to determine the applicability of the code for the analysis of fighter configurations. Two configurations were studied, a wing-body and a wing-body-chine. FL057 predicted pressure distributions, forces, and moments well at low angles of attack, at which the flow was fully attached. The FL057 predictions were also accurate for some test conditions once the leading edge vortex became well established. At the subsonic speeds, FL057 predicted vortex breakdown earlier than that seen in the experimental results. Placing the chine on the forebody delayed the onset of bursting and improved the correlation between numerical and experimental data at the subsonic conditions

Het wellness recovery action plan : herstel van paradigma naar praktijk

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