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A Direct Implementation of a Modified Boundary Integral Formulation for the Extended Fisher-Kolmogorov Equation

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Journal of Applied Mathematics and Physics（应用数学与应用物理） 2015年第10期

作者： Okey Oseloka Onyejekwe * Computational Science Program Addis Ababa UniversityArat Kilo CampusAddis AbabaEthiopia.

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The Effect of Time-Stepping on the Accuracy of Green Element Formulation of Unsteady Convective Transport

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Journal of Applied Mathematics and Physics 2014年第7期2卷 621-633页

作者： Okey Oseloka Onyejekwe Computational Science Program Addis Ababa University Arat Kilo Campus Addis Ababa Ethiopia

Despite the significant number of boundary element method (BEM) solutions of time-dependent problems, certain concerns still need to be addressed. Foremost among these is the impact of different time discretization schemes on the accuracy of BEM modeling. Although very accurate for steady-state problems, the boundary element methods more often than not are computationally challenged when applied to transient problems. For the work reported herein, we investigate the level of accuracy achieved with different time-discretization schemes for the Green element method (GEM) solution of the unsteady convective transport equation. The Green element method (a modified BEM formulation) solves the boundary integral theory (A Fredholm integral equation of the second kind) on a generic element of the problem domain in a way that is typical of the finite element method (FEM). In this integration process a new system of discrete equations is produced which is banded and hence amenable to matrix manipulations. This is subsequently deployed to investigate the proper resolution in both space and time for the chosen transient 1D transport problems especially those involving shock wave propagation and different types of boundary conditions. It is found that for three out of the four numerical models developed in this study, the new system of discrete element equations generated for both space and temporal domains exhibits accurate characteristics even for cases involving advection-dominant transport. And for all the cases considered, the overall performance relies heavily on the temporal discretization scheme adopted.

关键词： Boundary Element Method Green Element Method Unsteady Convective Transport Equation Advection Dominant Transport

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Synthesis and antileishmanial evaluation of some 2,3-disubstituted-4(3H)-quinazolinone derivatives

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Organic and Medicinal Chemistry Letters 2014年第1期4卷 1-7页

作者： Birhan, Yihenew Simegniew Bekhit, Adnan Ahmed Hymete, Ariaya Department of Chemistry Natural and Computational Science College Debre Markos University Debre Markos Ethiopia Department of Pharmaceutical Chemistry Alexandria University Alexandria 21215 Egypt Department of Pharmaceutical Chemistry and Pharmacognosy School of Pharmacy Addis Ababa University Addis Ababa Ethiopia

Background: Leishmaniasis is a neglected tropical parasitic diseases affecting millions of people around the globe. Quinazolines are a group of compounds with diverse pharmacological activities. Owing to their promising antileishmanial activities, some 3-aryl-2-(substitutedstyryl)-4(3H)-quinazolinones were synthesized in good yields (65.2% to 86.4%). Results: The target compounds were synthesized by using cyclization, condensation, and hydrolysis reactions. The structures of the synthesized compounds were determined using elemental microanalysis, infrared (IR), and proton nuclear magnetic resonance (1H NMR). The in vitro antileishmanial activities of the synthesized compounds were evaluated using Leishmania donovani strain. All the synthesized compounds displayed appreciable antileishmanial activities (IC₅₀ values, 0.0128 to 3.1085 μg/ml) as compared to the standard drug miltefosine (IC₅₀ = 3.1911 μg/ml). (E)-2-(4-chlorostyryl)-3-p-tolyl-4(3H)-quinazolinone (7) is the compound with the most promising antileishmanial activities (IC₅₀ = 0.0128 μg/ml) which is approximately 4 and 250 times more active than the standard drugs amphotericin B deoxycholate (IC₅₀ = 0.0460 μg/ml) and miltefosine (IC₅₀ = 3.1911 μg/ml), respectively. Conclusions: The results obtained from this investigation indicate that the synthesized and biologically evaluated quinazoline compounds showed promising antileishmanial activities and are good scaffolds for the synthesis of different antileishmanial agents. © 2014 Birhan et al.

关键词： Antileishmanial activities Leishmania Quinazolinones

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Application of Neutron Activation Analysis Technique for the Analysis of Soil Samples from Farmlands of Yebrage Hawariat, East Gojjam, Ethiopia

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Journal of Agricultural science and Technology(A) 2014年第4期4卷 342-352页

作者： Yihunie Hibstie Asres Ashok Kumar Chaubey Awoke Taddesse Hailu Dilbetigle Assefa Mamo Department of Physics College of Natural and Computational Science Debre Markos University Debre Markos (+251) Ethiopia Physics Department Addis Ababa University Addis Ababa (+251) Ethiopia

Farmers may not be conscious for their farmland＇s nutrients, soil organic matter, water and air because they simply concerned only for their labor availability and soil fertility losses. The composition and proportion of these components greatly influence soil physical properties, including texture, structure and porosity, the fraction of pore space in a soil. The soil of this farmland must be able to supply adequate amount of plant nutrients, in forms which can be absorbed by the crop, within its lifespan. Deficiencies or imbalances in the supply of any of essential elements can compromise growth, affecting root development, cell division, crop quality, crop yield and resistance to disease and drought. This study was conducted to fill this knowledge gap in order to develop economically vital and environmentally accepted nutrient management strategies for the use of soils in agricultural lands. The objective of this study is to assess the elemental contents and concentration of soil samples collected from farmlands of ＂Yebrage＂ using neutron activation analysis （NAA） techniques regardless of oxidation state, chemical form or physical locations. NAA is used to determine the elemental composition and concentrations present in a soil. The macro/micronutrient and organic matter deficiencies have been verified in agricultural soils through increased use of soil testing and plant analysis. The challenge for agriculture over the coming decades will meet the world＇s increasing demands for food in a sustainable way. Current issues and future challenges point out that as long as agriculture remains a soil based industry, major decreases in productivity likely to be attained ensuring that plants do not have adequate and balanced supply of nutrients.

关键词： NAA Yebrage Chemoga macro/micronutrient organic matter soil fertility cereal cropping.

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Plant Diversity and Vegetation Structure in Encroached and Non-encroached Areas of Borana Rangelands： The Case of Hallona and Medhacho Pastoralist Associations

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Journal of Agricultural science and Technology(A) 2014年第9期4卷 787-796页

作者： Niguse Bekele Dirbaba Mekuria Argaw Denboba Gemedo Dalle Tussie Department of Natural Resource Management Ambo University Ambo 19 Ethiopia Environmental Science Program Addis Ababa University Addis Ababa 1176 Ethiopia Ethiopian Institute of Biodiversity Addis Ababa 80119 Ethiopia

The Borana rangelands are important areas of cattle production in Ethiopia. However, these rangelands are threatened by the increasing changes in the natural vegetation from grass and forbs dominated into unpalatable bushy woody vegetation resulting in the loss of some of the highly desirable grass species. This study was conducted to assess the impacts of bush encroachment on the biodiversity, structure and cover of the native vegetation in bush encroached and non-encroached sites. Vegetation data were collected from both sites by laying quadrate plots along transects using a systematic sampling method. According to the results, higher number of species was recorded in the non-encroached sites than that in the encroached sites. The diversity indices for the non-encroached and the encroached sites were 3.16 and 2.67, respectively. The abundance and cover analysis indicated that there was high density and cover of herbaceous species in the non-encroached site. There was a significantly higher density of woody species cover in the encroached site. Generally, the bush encroachment in the Borana rangelands has hampered the diversity of the native vegetation, particularly the grasses and forbs and reduced the ground cover, exposing large parts of the rangelands for soil erosion and other degradation process.

关键词： Rangeland bush encroachment encroached non-encroached diversity shrubs.

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Current status of soil transmitted helminths and Schistosoma mansoni infection among children in two primary schools in North Gondar, Northwest Ethiopia: A cross sectional study

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BMC Research Notes 2014年第1期7卷 1-7页

作者： Mathewos, Biniam Alemu, Abebe Woldeyohannes, Desalegn Alemu, Agersew addis, Zelalem Tiruneh, Moges Aimero, Mulugeta Kassu, Afework Department of Immunology and Molecular Biology School of Biomedical and Laboratory Sciences University of Gondar Gondar Ethiopia Department of Medical Parasitology School of Biomedical and Laboratory Sciences University of Gondar Gondar Ethiopia Department of Medical Microbiology School of Biomedical and Laboratory Sciences University of Gondar Gondar Ethiopia Department of Biology Faculty of Natural and Computational Sciences University of Gondar Gondar Ethiopia Department of Public Health School of Medical and Health Sciences Addis Ababa Science and Technology University Addis Ababa Ethiopia

Background: School age children are one of the groups at high risk for intestinal parasitic infections especially in developing countries like Ethiopia as the supply of good quality drinking water and latrine coverage are poor. Though there are previous data on the prevalence of soil transmitted helminths (STHs) and Schistosoma mansoni infection among these high risk groups current status in the study area is unknown. Therefore, the aim of this study was to determine the current prevalence and associated risk factors of STHs and S. mansoni infections among school children. Methods. A cross-sectional study was carried out in Gorgora and Chuahit towns, North Gondar Zone, North West Ethiopia from January 20 to February 25, 2012 involving 261 school children. A pre-tested and structured questionnaire was used to collect socio-demographic data and possible risk factors. Stool samples were collected and examined for intestinal parasites using Kato Katz method. Chi-square test was used to see if there is association between sociodemographic factors and other risk factors for STH and S. mansoni infection and odds ratio with 95% CI was computed as measures of association. P < 0.05 was taken as statistically significant. Results: Out of the 261 study participants, 174 (66.7%) were infected with one or more species of intestinal parasites. Ascaris lumbricoides was the predominant isolates (39.8%) followed by Trichuris trichiura (6.1%) and Hookworms (4.9%). Schistosoma mansoni was detected in 33.7% of the children. Among infected individuals, 9.5% were coinfected by S. mansoni and A. lumbricoides and 1.5% with S. mansoni and T. trichiura. Swimming habit (OR: 2.536, 95% CI: 1.122, 5.737, P = 0.022) was significantly associated with S. mansoni infection. Conclusion: The prevalence of STH and S. mansoni was high among school children. This should call for implementation of an integrated strategy to reduce morbidity and control of transmission of STH and S. mansoni. © 2014 Mathewos

关键词： Schistosoma mansoni School children Soil transmitted helminths

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EXAFS studies of novel impulsive hardening in theBe–Zn–Sesemiconductor alloys

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Advances in Synchrotron Radiation 2014年第1期3卷

作者： Javed Mazher Shabina Khan Pankaja Singh Materials Science Program Addis Ababa University P. O. Box 1176 Addis Ababa Ethiopia Physics Department Government Motilal Vigyan Mahvidyalaya Barkatullah University Bhopal 462001 India

Beryllium doping has been used to harden the inherently soft zinc-selenides semiconductor mixed alloys. Stoichiometric semiconductor ternary alloys of Be x Zn 1-x Se have been synthesized by the Bridgeman technique. Extended X-ray absorption fine structure (EXAFS) spectroscopy — in a state-of-art synchrotron-based method — is performed by varying the dopant Be concentration of Be from 6% to 55% in the zinc–selenide host semiconductor. EXAFS analyses is carried out to study the next neighbor and next nearest neighbor atomic positions, nature of the substitutional doping, extent of bond length homogeneity, presence of involuntary contrast among the path distances, and the cross over from soft to hard character of the ternary on increasing Be concentration. Our results indicate the presence of an impulsive nature of hardening in the ternary with a disparity at the lower and the higher doping levels. The observation of impulsive hardening of the substitutional dopants in the semiconductor lattice is explained by the help of self-accommodative attributes of the host lattice.

关键词： II–VI semiconductors mixed ternary alloys synchrotron-based XAS EXAFS analysis solid solution hardening

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18th European Symposium on Radiopharmacy and Radiopharmaceuticals Salzburg, Austria. 7-10 April 2016

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EJNMMI RADIOPHARMACY AND CHEMISTRY 2016年第1期1卷 1-37页

作者： [Anonymous] Los Alamos National Laboratory Los Alamos USA Oak Ridge National Laboratory Oak Ridge USA Department of Nuclear Medicine Medical University Innsbruck Innsbruck Austria Department of Radiology & Nuclear Medicine Radboud University Medical Center Nijmegen The Netherlands Institute of Molecular and Translational Medicine Faculty of Medicine and Dentistry Palacky University Olomouc Czech Republic Département de Médecine Nucléaire et Radiobiologie Faculté de Médecine et Sciences de la Santé Université de Sherbrooke Sherbrooke Canada Centre d’Imagerie Moléculaire de Sherbrooke (CIMS) CR-CHUS Sherbrooke Canada Division of Molecular Biology/Biocenter Medical University Innsbruck Innsbruck Austria Department of Nuclear Medicine Radboud University Medical Center Nijmegen The Netherlands IENI-CNR Padua Italy DiSCOG-University of Padua Padua Italy IOV Padua Padua Italy IC-CNR Bari Italy IBB-CNR Naples Italy Laboratory of Radiopharmacy KU Leuven Leuven Belgium Micro Flow Chemistry & Process Technology Chemical Engineering and Chemistry Department TU Eindhoven Eindhoven The Netherlands Laboratory for Radiopharmacy University of Leuven Leuven Belgium Department of Nuclear Medicine and Molecular Imaging University of Leuven Leuven Belgium Department of Medicine and Surgery Tecnomed Foundation University of Milano-Bicocca Milan Italy Dipartimento di Biotecnologie Mediche e Medicina Traslazionale Università degli Studi di Milano Milan Italy Department of Radiology & Nuclear Medicine VU University Medical Center Amsterdam The Netherlands Department of Clinical Pharmacology & Pharmacy VU University Medical Center Amsterdam The Netherlands Université de Lorraine Vandoeuvre les Nancy France NancycloTEP Plateforme d’imagerie expérimentale Vandoeuvre les Nancy France CNRS UMR 7565 SRSMC Vandoeuvre les Nancy France CHU de Nancy-Brabois Vandoeuvre les Nancy France Department of Biomedical Imaging and Image-guided Therapy Division of Nuclear Medicine Medical Univers

Table of contents OP03 Selective extraction of medically-related radionuclides from proton-irradiated thorium targets V. Radchenko, J.W. Engle, C. Roy, J. Griswold, M.F. Nortier, E.R. Birnbaum, M. Brugh, S. Mirzadeh, K. D. John, M.E. Fassbender OP04 Comparison of [68Ga]FSC(succ-RGD)3 and [68Ga]NODAGA-RGD for PET imaging of alpha v beta 3 integrin expression Chuangyan Zhai, Gerben M. Franssen, Milos Petrik, Peter Laverman, Clemens Decristoforo OP05 A new NPY-Y1R targeting peptide for breast cancer PET imaging Ait-Mohand Samia, Dumulon-Perreault Veronique, Guerin Brigitte OP06 The influence of multivalency on CCK 2 receptor targeting D. Summer, A. Kroess, C. Rangger, H. Haas, P. Laverman, F. Gerben, E. von Guggenberg, *** OP07 SPECT Imaging of alpha v beta 3 Expression by [99mTc(N)PNP43]- Bifunctional Chimeric RGD Peptide not Cross-Reacting with alpha v beta 5 Cristina Bolzati, Nicola Salvarese, Fiorenzo Refosco, Laura Melendez-Alafort, Debora Carpanese, Antonio Rosato, Michele Saviano, Annarita Del Gatto, Daniela Comegna, Laura Zaccaro OP09 New dienophiles for the inverse-electron-demand Diels-Alder reaction and for pretargeted PET imaging Emilie Billaud, Muneer Ahamed, Frederik Cleeren, Elnaz Shahbazali, Tim Noel, Volker Hessel, Alfons Verbruggen and Guy Bormans OP10 New complexing agent for Al18F-labelling of heat-sensitive biomolecules: Synthesis and preclinical evaluation of Al18F-RESCA1-HAS Cleeren F, Lecina J, Koole M, Verbruggen A and Bormans G OP11 A novel versatile precursor efficient for F-18 radiolabelling via click-chemistry B. Lugatoa, S. Stucchia, E.A. Turollaa, L. Giulianoa, ***, P. Ferraboschib OP12 A general applicable method to quantify unidentified UV impurities in radiopharmaceuticals R.P. Klok, M.P.J. Mooijer, N.H. Hendrikse, A.D. Windhorst OP13 Development of [F-18]Fluoro-C-glycosides to radiolabel peptides Collet C., Petry N., Chretien F., Karcher G., Pellegrini-Moise N., Lamande-Langle S. OP14 A Microfluidic Approach for the 68

关键词： Positron Emission Tomography Single Photon Emission Compute Tomography Standard Uptake Value Positron Emission Tomography Imaging High Pressure Liquid Chromatography

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Releasing the Power of Variability: Towards Constraint Driven Quality Assurance

Releasing the Power of Variability: Towards Constraint Drive...

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IIAI International Conference on Advanced Applied Informatics (IIAIAAI)

作者： Yucong Duan Ajay Kattepury Fekade Getahun Abdelrahman Elfakiz Wencai Du College of information science and technology Hainan University China ARLES Group Addis Ababa Univ. Arles France Department of Computer Science Addis Ababa University France Department of Computer Science Addis Ababa University Management and Science University Shah Alam Selangor MY HNU Research program

We identify that Over Design(OD) and Under Design(UD) as two basic forms of negative variability construction which can lead to both functional incompleteness and unexpected quality of both design time and run time. To make our approach practical to a whole software production processes, we propose to evaluate and measure OD and UD in terms of values under economical goals which are concretized with the functionality implementation and the quality management of a quality lifecycle. We work towards relieving OD and UD in terms of variability construction within a variability space.

关键词： Software Unified modeling language Economics Business Semantics Educational institutions Software measurement

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Capital flow analysis: Application in analysis of digital ecosystem infrastructure establishment and sustainability in a developing economy 12

Capital flow analysis: Application in analysis of digital ec...

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International Conference on Management of Emergent Digital EcoSystems, MEDES 2012

作者： Debay, Workshet Lamenew Teklu, Tilahun Watson, Richard T. IT-PhD Program School of Information Science Addis Ababa University Ethiopia School of Management Addis Ababa University Ethiopia MIS Department University of Georgia United States

ISBN: (纸本)9781450317559

In this study, capital flow analysis is applied based on ecosystem theory to develop an understanding of the establishment and sustainability of digital ecosystem infrastructure in a developing economy. For empirical understanding cases were taken from university-wide network development initiatives in addis ababa university, Ethiopia, and from continued efforts that realized the Ethiopian Educational and Research Network (EthERNet). The study attempts to identify mechanisms for the initiatives and continued contributions to maintain the health of digital ecosystem infrastructure. Critical realism is employed as an approach for the investigation. The analysis of the cases demonstrates the value of capital flow analysis to understand the healthiness of digital ecosystem infrastructure. Based on the results obtained, the study also proposes a model to investigate on the sustainability of broader digital ecosystems infrastructure in the country. Copyright © 2012 ACM.

关键词： Ecosystems

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