检索结果-内蒙古大学图书馆

Effects of Salinity on Days to Heading (DTH), Days from Heading to Maturity (DHTM) and Days to Maturity (DTM) of tef [Eragrostis tef (Zucc.) Trotter] Accessions and Varieties in Ethiopia

引用

Asian Journal of Agricultural sciences 2011年第4期3卷 250-256页

作者： Kinfemichael Geressu Asfaw Fisseha Itanna Danno Biology Department College of Natural and Computational Sciences (CNCS) Mekelle University (MU) Plant Biology and Biodiversity Program Unit Faculty of Life Science College of Natural Sciences Addis Ababa University (AAU)

Salinity is a continuing problem in the arid and semi-arid tracts of the world. It could be alleviated using irrigation management and/or crop management. However, the former approach is outdated and very expensive. Nevertheless, the latter is economical as well as efficient, and it enables to produce salt tolerant crop lines. But prior to that there is a need to confirm the presence of genetic based variation for salt tolerance among different species or varieties of a particular crop that can thrive under unreliable agro-ecological situations; tef [Eragrostis tef (Zucc) Trotter] is one of such crops. Thus fifteen lowland tef genotypes (10 accessions and 5 varieties) were tested with respect to days to heading, days from heading to maturity and days to maturity at 2, 4, 8 and 16 dS/m salinity levels. Distilled water (0 dS/m) was used as a control. Data analysis was carried out using SAS package. The analyzed data showed significant variation among all the three parameters recorded for accessions and varieties (p<0.001) and for treatments (p<0.01). Increased salinity level caused delayed Days to Heading (DTH), Days from Heading to Maturity (DHTM) and Days to Maturity (DTM) with a few exceptions. Days to Maturity (DTM) was more salt affected than Days from Heading to Maturity (DHTM) and Days to Heading (DTH). Accessions 212611 and 205217 were the most salt sensitive and salt tolerant genotypes respectively. With respect to the parameters investigated, accessions showed broad intraspecific variation for salt tolerance unlike varieties.

关键词： Accessions Eragrostis tef grain filling NaCl salinity varieties

来源：评论

学校读者我要写书评

暂无评论

Effects of Salinity on Yield and Yield Components of tef [Eragrostis tef (Zucc.) Trotter] Accessions and Varieties

引用

Current Research Journal of Biological sciences 2011年第4期3卷 289-299页

This study aimed to screen fifteen low land tef genotypes (10 accessions and 5 varieties) with respect to yield and yield components at 0dS/m (control), 2, 4, 8 and 16 dS/m salinity levels and data analysis was carried out using SAS package (SAS version 8.2, 2001). The two ways ANOVA showed significant variation with respect to Main Panicle Length (MPL), Peduncle Length (PDL), number of spikelets per main panicle (SP/MP), number of Primary Panicle Branch per Main Panicle (PPB/MP), Main Panicle Dry Weight (MPDW) and Grain Yield per Main Panicle (GY/MP) at p<0.001 for both accessions/varieties and treatment. On the other hand, accession/variety*treatment interaction effect was significant for MPDW (p<0.001) and SP/MP (p<0.01). This implies that all the accessions and varieties respond to salinity stress differently with respect to these two characters. However, the accession/variety*treatment interaction for the rest characters was insignificant reflecting that the entire varieties and accessions react to salinity stress similarly. Accession 236514, varieties DZ-Cr-358 and DZ-01-1681 were salt sensitive genotypes whereas accession 237186 and variety DZ-cr-37 were salt tolerant genotypes of all. Generally, the study revealed the presence of broad intraspecific genetic variation in tef accessions and varieties for salt tolerance but more in the former. Irrespective of salinity being a growing problem in Ethiopia in general and the Awash valley in particular, only little has been done on crops salt tolerance. Therefore, to alleviate the already existing and the inevitable incoming salinity problem, there should be similar and profound studies on tef and other crops.

关键词： Grain yield panicle peduncle salinity spikelet number yield components

来源：评论

学校读者我要写书评

暂无评论

Response of Dry Matter Production of tef [Eragrostis tef (Zucc.) Trotter] Accessions and Varieties to NaCl Salinity

引用

Current Research Journal of Biological sciences 2011年第4期3卷 300-307页

作者： Kinfemichael Geressu Asfaw Fisseha Itanna Danno Biology Department College of Natural and Computational Sciences (CNCS) Mekelle University (MU) Plant Biology and Biodiversity Program Unit Faculty of Life Sciences College of Natural Sciences Addis Ababa University (AAU)

This study aimed to screen fifteen low land tef genotypes (10 accessions and 5 varieties) with respect to dry matter production at 0 dS/m (control), 2, 4, 8 and 16 dS/m salinity levels. Data analysis was carried out using SAS package (SAS version 8.2, 2001) and SPSS version 12. The two ways ANOVA showed significant variation with respect to root dry weight per plant (RDW) at p<0.001 and total dry weight per plant (TDW) at p<0.05 for accessions/varieties. Moreover, it was significant for treatment (p<0.001) with respect to all the above three parameters. On the other hand, the two ways ANOVA for accession/variety*treatment interaction was significant for above ground dry weight per plant (AGDW) and total dry weight per plant (TDW) at p<0.01. This implies that all the accessions and varieties respond to salinity stress differently with respect to these three dry matter production characters. However, the two ways ANOVA for the accession/variety*treatment interaction for root dry weight per plant (RDW) was insignificant reflecting that the entire varieties and accessions react to salinity stress similarly. Accessions 212611, 55017, 231217 and varieties DZ-Cr-358 and DZ-01-1281 were salt sensitive genotypes whereas accessions 237131, 237186, 212928 and variety DZ-Cr-37 were salt tolerant genotypes of all. Varieties were more salt affected than accessions with respect to dry matter production.

关键词： Dry matter Eragrostis tef root weight salinity shoot weight varieties

来源：评论

学校读者我要写书评

暂无评论

Pattern Recognition and Knowledge Discovery from Road Traffic Accident Data in Ethiopia: Implications for improving road safety

Pattern Recognition and Knowledge Discovery from Road Traffi...

引用

World Congress on Information and Communication Technologies

作者： Tibebe Beshah Dejene Ejigu Ajith Abraham Vaclav Snasel Pavel Kromer IT Doctoral Program Addis Ababa University Department of Computer Science VSB-Technical University of Ostrava

ISBN: (纸本)9781467301275

This research tries to view accident data collection and analysis as a system that requires a special view towards understanding the whole and making sense out of it for improved decision making in the effort of reducing the problem of road safety. Under the umbrella of an information architecture research for road safety in developing countries, the objective of this machine learning experimental research is to explore and predict the role of road users on possible injury risks. The research employed Classification and Adaptive Regression Trees (CART) and RandomForest approaches. To identify relevant patterns and illustrate the performance of the techniques for the road safety domain, road accident data collected from addis ababa Traffic Office is exposed to many sided analyses. Empirical results showed that the models could classify accidents with promising accuracy.

关键词： Road Safety Road Accident RandomForest CART

来源：评论

学校读者我要写书评

暂无评论

The water resource implications of planned development in the lake Tana catchment, Ethiopia

引用

Ecohydrology and Hydrobiology 2010年第2-4期10卷 211-221页

作者： Alemayehu, Tadesse Mccartney, Matthew Kebede, Seifu Environmental Science Program Addis Ababa University Addis Ababa P.O. Box 20763 (home) Ethiopia International Water Management Institute Addis Ababa P.O. Box 5689 Ethiopia Department of Earth Science Addis Ababa University Addis Ababa P.O. Box 1176 Ethiopia

The water resources of the Lake Tana catchments are largely untapped. Currently, water resource development is being promoted to stimulate economic growth. This study utilized the WEAP model to determine the likely impact of a number of possible development scenarios on lake water levels. For each scenario, the model was used to simulate water demand in three sectors (i.e. irrigation, hydropower and downstream environmental flows) over a 36-year period of varying flow and rainfall. The simulation results revealed that if all the planned development occurs on average 2198 GWhy^-1 power could be generated and 677 Mm³ y^-1 of water supplied to irrigation schemes. However, the mean annual water level of the lake would be lowered by 0.44 meters. As well as adverse ecological impacts this would have significant implications for shipping and the livelihoods of local people.

关键词： Ethiopia Lake tana Water demand Water level Water resources development WEAP model

来源：评论

学校读者我要写书评

暂无评论

Soil and rock characterization in the Mekele area, Northern Ethiopia

引用

International Journal of Earth sciences and Engineering 2010年第6期3卷 762-774页

作者： Berhane, Gebremedhin Ayenew, Tenalem Department of Earth Sciences College of Natural and Computational Sciences Mekele University P.O.Box 1202 Mekele Ethiopia Department Earth Sciences Faculty of Science Addis Ababa University P.O.Box 1176 Addis Ababa Ethiopia

Engineering geological map of Mekele town and its environs has been established for the first time after characterizing the geotechnical property of soils and rocks in the field and laboratory. Geological, geotechnical and engineering geological condition of Mekele area was characterized in relation to their effects to civil engineering structures. The engineering geological and geotechnical condition of the rocks and soils was studied on the bases of field description, simple in-situ geotechnical test and laboratory analysis. The dominant lithologic units are Quaternary sediment deposits (alluvial and residual soils), dolerite, sandstone, limestone-marl-shale intercalation and bedded limestone. The laboratory tests revealed that soils have medium to very high plasticity. The liquid limit of the soils varies from 50-80.8% for alluvial;29.4-67% for residual. The dolerite shows variable engineering property in terms of strength from weak rock mass strength to very high rock mass strength;the sandstone and limestone-marl-shale intercalation show low or weak rock mass strength and the bedded limestone have high rock mass strength. The engineering geological map is believed to provide basic information for site selection and land use planning in the area. © CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.

关键词： Limestone

来源：评论

学校读者我要写书评

暂无评论

Hybrid distance water learning in Ethiopia

Hybrid distance water learning in Ethiopia

引用

2009 34th WEDC International Conference - Water, Sanitation and Hygiene: Sustainable Development and Multisectoral Approaches

作者： Jan Teun Visscher, A. Seyoum Leta, B. Jackson Wandera, C. Lenneke Knoop, D. Hugo De Vos, E. Darja Kragic, F. Raktima Mukherjee, G. MetaMeta Communications Costerweg 1D 6702 AA Wageningen Netherlands Addis Ababa University Environmental Science Program P.O. Box 33348 Addis Ababa Ethiopia

ISBN: (纸本)9781843801337

Ethiopia is among the countries with lowest water and sanitation coverage in Africa. To meet with the countries ambitious Millennium Development Goals there is an urgent need for capacity building in the water sector. This paper describes an innovative project that developed a new approach for practice based selflearning for local staff working at Woreda level. This approach combines conventional paper based Distance Learning with CD-rom and E-based learning, supported by a network of trainers and resource persons. The paper describes the approach and presents a way forward to support large numbers of sector staff learning to apply improved intervention strategies in their job environment.

关键词： Sanitation

来源：评论

学校读者我要写书评

暂无评论

Reconstructing the Environmental Context of Human Origins in Eastern Africa Through Scientific Drilling

引用

Earth and Planetary sciences 1000年第1期50卷 451-476页

作者： Andrew S. Cohen Christopher J. Campisano J. Ramón Arrowsmith Asfawossen Asrat Catherine C. Beck Anna K. Behrensmeyer Alan L. Deino Craig S. Feibel Verena Foerster John D. Kingston Henry F. Lamb Tim K. Lowenstein Rachel L. Lupien Veronica Muiruri Daniel O. Olago R. Bernhart Owen Richard Potts James M. Russell Frank Schaebitz Jeffery R. Stone Martin H. Trauth Chad L. Yost 1Department of Geosciences University of Arizona Tucson Arizona USA email: cohen@email.arizona.edu 2Institute of Human Origins School of Human Evolution and Social Change Arizona State University Tempe Arizona USA 3School of Earth and Space Exploration Arizona State University Tempe Arizona USA 5School of Earth Science Addis Ababa University Addis Ababa Ethiopia 4Department of Mining and Geological Engineering Botswana International University of Science and Technology Palapye Botswana 6Geosciences Department Hamilton College Clinton New York USA 7National Museum of Natural History Smithsonian Institution Washington DC USA 8Berkeley Geochronology Center Berkeley California USA 9Department of Earth and Planetary Sciences Rutgers University Piscataway New Jersey USA 10Institute of Geography Education University of Cologne Cologne Germany 11Department of Anthropology University of Michigan Ann Arbor Michigan USA 13Botany Department School of Natural Sciences Trinity College Dublin Ireland 12Department of Geography and Earth Science Aberystwyth University Aberystwyth United Kingdom 14Department of Geological Sciences and Environmental Studies Binghamton University Binghamton New York USA 15Lamont-Doherty Earth Observatory Columbia University Pallisades New York USA 16National Museums of Kenya Nairobi Kenya 17Department of Geology University of Nairobi Nairobi Kenya 18Department of Geography Hong Kong Baptist University Hong Kong 19Human Origins Program National Museum of Natural History Smithsonian Institution Washington DC USA 20Department of Earth Environmental and Planetary Sciences Brown University Providence Rhode Island USA 21Department of Earth and Environmental Systems Indiana State University Terre Haute Indiana USA 22Department of Geosciences University of Potsdam Potsdam Germany

Paleoanthropologists have long speculated about the role of environmental change in shaping human evolution in Africa. In recent years, drill cores of late Neogene lacustrine sedimentary rocks have yielded valuable high-resolution records of climatic and ecosystem change. Eastern African Rift sediments (primarily lake beds) provide an extraordinary range of data in close proximity to important fossil hominin and archaeological sites, allowing critical study of hypotheses that connect environmental history and hominin evolution. We review recent drill-core studies spanning the Plio–Pleistocene boundary (an interval of hominin diversification, including the earliest members of our genus Homo and the oldest stone tools), and the Mid–Upper Pleistocene (spanning the origin of Homo sapiens in Africa and our early technological and dispersal history). Proposed drilling of Africa's oldest lakes promises to extend such records back to the late Miocene. ▪ High-resolution paleoenvironmental records are critical for understanding external drivers of human evolution. ▪ African lake basin drill cores play a critical role in enhancing hominin paleoenvironmental records given their continuity and proximity to key paleoanthropological sites. ▪ The oldest African lakes have the potential to reveal a comprehensive paleoenvironmental context for the entire late Neogene history of hominin evolution.

关键词： continental scientific drilling human evolution East African Rift paleoclimate

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：