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Search Results: 1 - 10 of 137 matches for " Meron Teferi Taye "
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Validation of General Climate Models (GCMs) over Upper Blue Nile River Basin, Ethiopia  [PDF]
Andualem Shigute Bokke, Meron Teferi Taye, Patrick Willems, Shimelis Asefu Siyoum
Atmospheric and Climate Sciences (ACS) , 2017, DOI: 10.4236/acs.2017.71006
Abstract: Potential of climate change impact assessment on hydrology and water resources of rivers is increasing from time to time due to its importance for water resources planning and management in the future. In order to carry out climate change impact studies, using General Climate Models (GCM) is a common practice and before using any of these models, it is essential to validate the models for the selected study area. Blue Nile River is one of the most sensitive rivers towards climate change impacts. The main source of Blue Nile River is Lake Tana where the two adjacent tributary rivers, Ribb & Gumera, are located and the main object of this paper is validation of current 15 GCM outputs (IPCC-AR5) over these two rivers using empirical quantile perturbation downscaling technique. The performance of the downscaled outputs of GCMs were evaluated using statistical indicators and graphical techniques for evapotranspiration, rainfall and temperature variables using observed daily meteorological datasets collected from five stations (Addis Zemen, Bahirdar, Debretabor, Woreta and Yifag) for the control period 1971-2000. Analysis results showed that the correlation coefficient of all models for mean monthly (MM) rainfall are 12% - 45%; and the Bias and RMSE -46 mm to +169 mm and 62 mm to 241 mm, respectively. The Bias and RMSE for MM maximum temperature are -2.5°C to +35°C; and 1°C to 35°C whereas for MM minimum temperature -6°C to +22°C and 1.7°C to 23°C, respectively. For the case of MM evapotranspiration, which is estimated using FAO-Penman-Montheith equation, the Bias and RMSE values vary from -35 mm to +10 mm; and +11 mm to +36 mm, respectively. The variation in the performance level of these models indicates that there is high uncertainty in the GCM outputs. Therefore, to use these GCM models for any climate change studies in the basin, careful selection has to be made.
Chemical properties of wild coffee forest soils in Ethiopia and management implications  [PDF]
Taye Kufa
Agricultural Sciences (AS) , 2011, DOI: 10.4236/as.2011.24057
Abstract: The study aims at determining the status of soil chemical fertility in four wild coffee forests of southeastern and southwestern Ethiopia. Accordingly, soil samples were collected from surface and subsurface depths at three sites within each forest and analyzed for soil chemical properties. The results depicted that the soils at the four coffee forests did not reveal significant variations for most parameters, except Mg, CEC and C:N ratio. Significant variations were determined between the surface and subsurface soils of the four studied forests, partly indicating the impacts of anthropogenic factors on vegetation cover and soil fertility status along profile depth. At Harenna, surface soil had significantly higher total nitrogen and organic matter than sub-surface soil. The decline in available phosphorus with soil depth was also significant at the Harenna and Yayu forests. Most soil results were comparable and showed inter- and intra-forest variations, demonstrating the contributions of vegetation cover and climate gradients. The study revealed the declined soil quality parameters with increased depth, demonstrating the vulnerability of forest soils to human-induced disturbances of natural habitats and land degradation, coupled with climate changes. Overall, the results underline the need for a multi-site forest conservation and promote productivity of high quality coffee standards. This demands urgent supports for implementing community-oriented management and incentive options towards maintaining environmental sustainability and coffee genetic resources for global benefits.
Biomass production and distribution in seedlings of Coffea Arabica genotypes under contrasting nursery environments in southwestern Ethiopia  [PDF]
Taye Kufa
Agricultural Sciences (AS) , 2012, DOI: 10.4236/as.2012.36101
Abstract: In Ethiopia, the natural forests with the occurrence of wild Arabica coffee gene pools are under constant threats, largely due to anthropogenic activities. The study was conducted to compare the variability among the wild arabica coffee genotypes in biomass assimilation and allocation patterns under varying light and irrigation conditions at the Jimma Research Center, southwestern Ethiopia. The treatments included irradiance (moderate and full sunlight), irrigation (well watered and water stressed) regimes and twelve coffee genotypes of different geographical areas. One-year-old seedlings were used to record dry mass of leaves, main stem, primary branches and root growth. Each organ was separately oven-dried and total dry matter production and allocation patterns were measured and analyzed. The results depicted highly significant differences between the contrasting irradiance and irrigation regimes as well as among coffee genotypes. Significantly the lowest and highest stems dry mass values recorded for Berhane-Kontir and Harenna genotypes, respectively. Most accessions had relatively lower assimilations in shade as compared to full sun light conditions. Likewise, coffee seedlings significantly differed in root dry mass and root to shoot ratio, dry matter partitioning due to the main and combined treatment effects. Overall, total biomass assimilation and partitioning were higher for unshaded, water stressed and Harenna genotypes from the respective treatment groups. Conversely, leaf dry matter, leaf share was significantly high under moderate shade environments. The total dry matter share varied for the seedling growth parts (root = 22%, leaf = 35%, stem = 43% and whole shoot = 78%). The root growth followed the order of Harenna > Yayu > Bonga > Berhane-Kontir populations. The reverse was true for the leaf and whole-shoots, demonstrating the completion between above and below ground growth parts and thus the need to consider both dry matter assimilation and partitioning patterns in identifying desirable genotypes and optimum environments for future breeding program in Ethiopia.
Determinants of alcohol drinking and its association with sexual practices among high school students in Addis Ababa, Ethiopia: Cross sectional study  [PDF]
Dawit Teshome, Teferi Gedif
Open Journal of Preventive Medicine (OJPM) , 2013, DOI: 10.4236/ojpm.2013.36057
Abstract: Introduction: Alcohol drinking and risky sexual practices have become serious public health problem among teenagers and young adults globally, including many developing countries. The available reports are sparse, especially there is a lack of recent and representative data for high school students in developing countries including Ethiopia. The aim of this study was to estimate the prevalence, identify determinants, and examine the association of alcohol drinking with sexual practices among high school students in Addis Ababa, capital city of Ethiopia. Methods: School based cross sectional study was conducted from November to December 2010. Multivariate logistic regression analysis was used to determine the association between students’ background characteristics and alcohol use, and alcohol use and sexual practices. Results: Among 2551 students surveyed, lifetime and current (past month) alcohol drinking was reported by 1166 (45.7%) and 676 (26.5%) students, respectively. Having sexual intercourse at least once in their lifetime was reported by 412 (16.2%) with151 (5.9%) of them being sexually active during a month prior to the survey. Having multiple sexual partners (52.5%), drinking alcohol before sexual intercourse (26.4%), and having sexual intercourse without the use of condom (47.3%) were also common among sexually active students. In adjusted logistic regression model, age (18 and 19 and older), living with 2 parents, getting pocket money, having alcohol drinking friends and attending general secondary school (grade 9-10) were positive predictors of current alcohol drinking. Nergative predictors of current alcohol drinking were being Protestant Christian and living with relatives or siblings. Conclusion: Alcohol drinking before sexual intercourse was a major problem among high school students in Addis Ababa, Ethiopia. Male gender, older age and higher school grade, friends influence, religious affiliation, living with parents and getting pocket money were significant predictors of current alcohol drinking. Educating about substance use and risky sexual behaviors, engaging students in extracurricular activities and restrict access to alcohol to high school students may help in solution of these problems on a local scale.
Knowledge on breast cancer and its prevention among women household heads in Northern Ethiopia  [PDF]
Befikadu Legesse, Teferi Gedif
Open Journal of Preventive Medicine (OJPM) , 2014, DOI: 10.4236/ojpm.2014.41006
Abstract:

Background: Breast cancer (BC) is one of the malignant diseases taking the lion’s share role in the devastating effects caused by cancer. BC related awareness and practice of females are known to have crucial contribution in the prevention and control efforts. The worst aspects of the disease in Ethiopia include absence of research and thus very limited information on any aspect. The study assessed knowledge and practice on BC among women household heads. Methods: A cross-sectional study was conducted on a sample of 845 women. The sample size was divided among five randomly selected kebeles (smallest government administrative units) proportional to the number of households. Samples were selected by systematic sampling technique. Data were collected by trained data collectors through a face-to-face interview using pre-tested, semi-structured questionnaire from female household heads. Pearson chi-square and logistic regression tests were used to assess the determinants of BC knowledge and breast cancer self examination (BSE) practice. Results: The respondents’ age ranged from 20 to 75 years with a mean age of 33.66 ± 10.8. Onefifth (19.8%) of the respondents were illiterate, while 257 (31.8%) had primary education. Majority of the

Phase fronts and synchronization patterns in forced oscillatory systems
Ehud Meron
Discrete Dynamics in Nature and Society , 2000, DOI: 10.1155/s1026022600000212
Abstract: This is a review of recent studies of extended oscillatory systems that are subjected to periodic temporal forcing. The periodic forcing breaks the continuous time translation symmetry and leaves a discrete set of stable uniform phase states. The multiplicity of phase states allows for front structures that shift the oscillation phase by π/n where n=1,2,…, hereafter π/n-fronts. The main concern here is with front instabilities and their implications on pattern formation. Most theoretical studies have focused on the 2:1 resonance where the system oscillates at half the driving frequency. All front solutions in this case are π-fronts. At high forcing strengths only stationary fronts exist. Upon decreasing the forcing strength the stationary fronts lose stability to pairs of counter-propagating fronts. The coexistence of counter-propagating fronts allows for traveling domains and spiral waves. In the 4:1 resonance stationary π-fronts coexist with π/2-fronts. At high forcing strengths the stationary π-fronts are stable and standing two-phase waves, consisting of successive oscillatory domains whose phases differ by π,, prevail. Upon decreasing the forcing strength the stationary π-fronts lose stability and decompose into pairs of propagating π/2-fronts. The instability designates a transition from standing two-phase waves to traveling four-phase waves. Analogous decomposition instabilities have been found numerically in higher 2n:1 resonances. The available theory is used to account for a few experimental observations made on the photosensitive Belousov–Zhabotinsky reaction subjected to periodic illumination. Observations not accounted for by the theory are pointed out.
Self-organization in interface dynamics and urban development
Ehud Meron
Discrete Dynamics in Nature and Society , 1998, DOI: 10.1155/s1026022699000163
Abstract: The view of the urban environment as an extended nonlinear system introduces new concepts, motivates new questions, and suggests new methodologies in the study of urban dynamics. A review of recent results on interface dynamics in nonequilibrium physical systems is presented, and possible implications on the urban environment are discussed. It is suggested that the growth modes of specific urban zones (e.g. residential, commercial, or industrial) and the factors affecting them can be studied using mathematical models that capture two generic interface instabilities.
Reflections on Israel's Public Diplomacy
Meron Medzini
Bulletin du Centre de Recherche Fran?ais de Jérusalem , 2012,
Abstract: La diplomatie publique d'Isra l a été souvent vilipendée en Isra l et à l'étranger. Ceci est largement d à une différence entre la politique et le marketing de la politique. Les critiques de la hasbara israélienne soutiennent généralement que le maigre financement, les luttes intestines et la multiplicité des organisations responsables, le faible niveau professionnel sont responsables de la médiocre image d'Isra l, surtout dans les pays occidentaux. Ils n'élargissent pas leur perspective jusqu'à voir que l'information soutient l'action, afin d'aider à formuler et à mettre en uvre une politique par un marketing adéquat. Il demeure que lorsqu'Isra l a poursuivi une politique positive, signé des traités de paix, fait des concessions, son image s'est considérablement améliorée. Quand le pays a choisi l'immobilisme, l'image s'est dégradée. Cet article décrit l'évolution de la diplomatie publique israélienne depuis 1948. Israel's public diplomacy has been the subject of much abuse and vilification both in Israel and abroad. This is largely due to the misunderstanding between policies and the marketing of those policies. Critics of Israel's Hasbara efforts usually argue that poor funding, organizational infighting, multiplicity of bodies dealing with Hasbara, low level and quality of officials are responsible for Israel's poor image mainly in Western countries. They fail to look at the broader picture in which information is a supporting action, designed to assist the formulation and implementation of a policy by marketing it properly. The fact remains that when Israel pursued what was seen as a positive policy, signed peace treaties and made territorial concessions, its image improved dramatically. When it adhered to a policy of immobilism its image plunged. The paper describes the evolution of Israel's public diplomacy since 1948.
Some Quality Changes During Storage of Cassava Roots.
Mulugeta Taye
Journal of Food Technology in Africa , 2000,
Abstract: Two storage experiments were done at Awassa College of Agriculture during the year 1995 to investigate the quality changes on cassava root. In each experiment, two cultivars namely, Amarokello red (local) and Umbure, and three storage methods, namely, earthen floor (ground), trench storage and sacks were factorially combined and were examined for vascular streak (primary deterioration), tuber weight loss, starch and total protein content. The blue coloured vascular streak which occurred closer to the rind was found non-significantly different between cultivars, and storage methods. Also, the starch content was almost similar between the storage methods, but was significantly (P<0.05) higher in cultivar Amarokello red than Umbure. The protein content showed little variation between the different storage methods and the cultivars. The Journal of Food Technology in Africa Volume 5 Number 2 (April - June 2000), pp. 64-65
Web-Based Ontology Languages and its Based Description Logics
Mohammad Taye
International Journal of ACM Jordan , 2011,
Abstract: The main object of semantic web languages is to add semantics to the existing information on the Web. These web languages have been developed to represent or express ontologies. Therefore, these description languages provide richer constructors for forming complex class expressions and axioms. An ontology is expressed in a knowledge representation language, which provides a formal frame of semantics. Since description logic is the basis of most ontology language, it is appropriate to explain briefly the base of the description to understand the ontology language clearly. The aim of this paper is to provide a brief survey of state-of-the-art ontology languages which are used to express ontology over the Web is provided. Also the goal of this paper is to provide a basic understanding of ontologies and description logics, which are the basis of ontology languages.
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