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American Journal of Plant Sciences 2012年第8期3卷 1041-1046页

作者： wondewosen shiferaw Alemayehu Balcha Hussen Mohammed Department of Plant and Horticultural Sciences Hawassa University Hawassa Ethiopia Jinka Agricultural Research Centre South Agricultural Research Institute Hawassa Ethiopia School of Agricultural Science Dilla University Dilla Ethiopia

Tef [Eragrostis tef (Zucc.)Trotter] is an ancient and major cereal crop in Ethiopia. Increasing tef grain yield partly requires developing cultivars that are adapted to drought stress environment. An experiment was carried out using 18 tef genotypes grown during September to December, 2010, under two water supply environments (stress during grain filling period, and non-stress) to identify genetic variation, heritability and correlations of grain yield and yield related traits. Broad-sense heritability values under respective stress and non-stress environments were grain yield (g/m2) 0.80 and 0.89, total biomass (g/m2) 0.89 and 0.73, harvest index 0.69 and 0.79, panicle weight (g/plant) 0.93 and 0.92, and seed weight (g/plant) 0.96 and 0.86. The correlations of grain yield under respective stress and non-stress environments were total biomass rp = 0.64, rg = 0.70, and rp = 0.48, rg = 0.56, harvest index rp = 0.70, rg = 0.64, and rp = 0.87, rg = 0.90, panicle weight rp = 0.98, rg = 1.00, and rp = 0.96, rg = 1.00, and seed weight/plant rp = 0.98, rg = 1.00, and rp = 0.90, rg = 1.00. The present experiment showed that either grain yield per se, or seed weight/plant could be used to improve grain yield under stress and non-stress environments.

关键词： Variability Broad-Sense Heritability Correlations Moisture Stress Eragrostis tef

Mathematical model and optimal control analysis of coffee berry borer with temperature and rainfall variability

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International Journal of Biomathematics 2024年第5期17卷 177-204页

作者： Abdisa shiferaw Melese Department of Applied Mathematics Adama Science and Technology UniversityAdamaEthiopia

This study focuses on a nonlinear deterministic mathematical model for coffee berry borer(Hypothenemus hampei)with temperature and rainfall *** the model analysis,CBB free and coexistence equilibria are *** basic reproduction numbers at a minimum and maximum temperature and rainfall are *** qualitative analysis of the model revealed the scenario for equilibria together with basic reproduction *** local stability of equilibria is established through the Jacobian matrix and the Routh-Hurwitz criteria,while the global stability of equilibria is demonstrated using an appropriate Lyapunov *** normalized sensitivity analysis has also been performed to observe the impact of different parameters on basic reproduction *** proposed model is extended into an optimal control problem by incorporating two control variables,namely,the preventive measure variable based on the separation of susceptible coffee berries from contacting the pests based on biological control and an increase in the death rate of colonizing females of CBB based on chemical *** disease control analysis is examined using Pontryagin's minimum ***,the numerical simulations are performed based on analytical results and are discussed ***,the cost-effectiveness of control strategies to determine the best approach to minimize the CBB burden was *** study is significant in providing reliable information on how one can use mathematical modeling to improve the roles of control strategies and prevention in CBB transmission in a coffee *** outcome of the study may guide public agriculture policymakers on optimal control strategies to control the *** particular,using chemical pesticides is very effective to combat pests with minimum costs.

关键词： Hypothenemus hampei climate variability optimal control cost-effective analysis numerical simulation

Genetic Variation for Grain Yield and Yield Related Traits in Tef [Eragrostis tef (Zucc.)Trotter] under Moisture Stress and Non-Stress Environments

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A comparative assessment on regeneration status of indigenous woody plants in Eucalyptus grandis plantation and adjacent natural forest

American Journal of Plant Sciences（美国植物学期刊） 2012年第8期

作者： wondewosen shiferaw Alemayehu Balcha Hussen Mohammed

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Journal of Forestry Research 2009年第1期20卷 31-36页

作者： shiferaw Alem Tadesse Woldemariam Ethiopian Institute of Agricultural Research Forestry Research Center P.O. Box 30708 Addis Ababa Ethiopia Addis Ababa University Department of Biology Education P.O.Box 1176 Addis Ababa Ethiopia

Diversity, density and species composition of naturally regenerated woody plants under Eucalyptus grandis plantation and the adjacent natural forest were investigated and compared. Twenty plots, with an area of 20 m × 20 m for each, were established in both of E. grand＆ plantation and adjacent natural forest, independently. In each plot, species name, abundance, diameter and height were recorded. Numbers of seedling were collected in five sub-plots （4 m2） within each major plot. A total of 46 species in the plantation, and 52 species in the natural forest, which belongs to 36 families were recorded. The diversity of species （H＇） is 2.19 in the plantation and 2.74 in the natural forest. The density of understory woody plant was 3842 stems/ha in the plantation and 4122 stems/ha in the natural forest. The densities of seedlings in the natural forest and the plantation were 8101 stems/ha and 4151 stems/ha, respectively. High similarity of woody species composition was found between the natural forest and the plantation. The E. grand＆ plantation was found favoring the regeneration and growth of Millitiaferruginia and Coffea arabica in a much better way than other underneath woody species.

关键词： E. grandis, natural forest natural regeneration plantation woody species diversity

Anthropogenic effects on floristic composition, diversity and regeneration potential of the Debrelibanos Monastery forest patch, central Ethiopia

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Journal of Forestry Research 2019年第6期30卷 2151-2161页

作者： Wakshum shiferaw Tamrat Bekele Sebsebe Demissew College of Natural Sciences Plant Biology and Biodiversity Management Addis Ababa University

This study assesses the effects of human disturbance on:(1)floristic composition,diversity,and plant community types;and,(2)the regeneration potential of woody species in the Debrelibanos Monastery forest patch in the North Showa zone of Oromia National Regional State,*** sample quadrats were placed on parallel transect lines along altitudes in the forest using a systematic sampling *** of 1 m^2,100 m^2 and 400 m^2 were used for recording herbaceous/seedling,sapling and tree species,respectively,with symptoms of different human disturbance *** hundred and thirteen species belonging to 52 families were recorded in the forest *** results show 459.5 stems ha^-1 of tree/shrub species *** community types,namely Juniperus procera–Acacia lahai,Carissa spinarum–Acacia abyssinica,Olea europaea ***–Euphorbia abyssinica and Ficus sur–Allophylus abyssinicus were *** overall Shannon–Wiener diversity index was *** regeneration patterns of some species were ***,altitude and human activities had significant effects on vegetation patterns and imply that current management practices are not satisfactory to sustain the *** improved management interventions are made,the sustainability of forest services will be at stake.

关键词： Anthropogenic impacts Composition Community Debrelibanos Diversity

Malaria helminth co-infections and their contribution for aneamia in febrile patients attending Azzezo health center,Gondar,Northwest Ethiopia:a cross sectional study

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Asian Pacific Journal of Tropical Medicine 2012年第10期5卷 803-809页

作者： Abebe Alemu Yitayal shiferaw Aklilu Ambachew Halima Hamid School of Biomedical and Laboratory Sciences.College of Medicine and Health Sciences University of GondarGondarEthiopia

Objective:To assess the prevalence of malaria helminth co-infections and their contribution for aneamia in febrile patients attending Azzezo health center,Gondar,Northwest Ethiopia. Methods:A cross section study was conducted among febrile patients attending Azezo health center from February-March 30,*** sampling technique was used to select 384 *** capillary blood and stool were *** stained thick and thin blood film were prepared for identification of Plasmodium species and stool sample was examined by direct wet mount and formalin-ether concentration technique for detection of intestinal helminthes *** concentration was determined using a portable haemoglobin spectrophotometer,Hemocue Hb 201 ***:Out of 384 febrile patients examined for malaria parasites,44(11.5%) individuals were positive for malaria parasites,of which Plasmodium vivax accounted for 75.0%(33),Plasmodium falciparum for 20.5%(9| infectious,whereas two person (4.5%) had mixed species *** of malaria was higher in males(28) when compared with prevalence in females(16).More than half(207,53.9%) of study participants had one or more *** was slightly higher in females(109,52.7%) than in males(98,47.3%).About helminths,Ascaris lumbricoides was the predominant isolate(62.1%) followed by hookworms(18.4%). Only 22 participants were co-infected with malaria parasite and helminths and co-infection with Ascaris lumbricoides was predominant(45.0%).The prevalence of anemia was 10.9%and co-infection with Plasmodium and helminth parasites was significantly associated with(P<0.000 1) higher aneamia prevalence compared to individuals without any ***: Prevalence of malaria and soil transmitted helminths is high and the disease is still major health problem in the study ***,simultaneous combat against the two parasitic infections is very crucial to improve health of the affected communities

关键词： Malaria Helminth Aneamia Febrile

Co-dynamics of COVID-19 and TB with COVID-19 vaccination and exogenous reinfection for TB:An optimal control application

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Infectious Disease Modelling 2023年第2期8卷 574-602页

作者： Zenebe shiferaw Kifle Legesse Lemecha Obsu Department of Mathematics Adama Science and Technology UniversityAdamaEthiopia

COVID-19 and Tuberculosis(TB)are among the major global public health problems and diseases with major socioeconomic *** dynamics of these diseases are spread throughout the world with clinical similarities which makes them difficult to be *** this study,we formulate and analyze a mathematical model containing several epidemiological characteristics of the co-dynamics of COVID-19 and *** conditions are derived for the stability of both COVID-19 and TB sub-models *** certain conditions,the TB sub-model could undergo the phenomenon of backward bifurcation whenever its associated reproduction number is less than *** equilibria of the full TBCOVID-19 model are locally asymptotically stable,but not globally,due to the possible occurrence of backward *** incorporation of exogenous reinfection into our model causes effects by allowing the occurrence of backward bifurcation for the basic reproduction number R_(0)η*).The analytical results show that reducing R_(0)<1 may not be sufficient to eliminate the disease from the *** optimal control strategies were proposed to minimize the disease burden and related *** existence of optimal controls and their characterization are established using Pontryagin's Minimum ***,different numerical simulations of the control induced model are carried out to observe the effects of the control *** reveals the usefulness of the optimization strategies in reducing COVID-19 infection and the co-infection of both diseases in the community.

关键词： COVID-19 Co-infection Exogenous reinfection Basic reproduction number Bifurcation Optimal control

Invasion of Prosopis juliflora and its effects on soil physicochemical properties in Afar region,Northeast Ethiopia

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International Soil and Water Conservation Research 2021年第4期9卷 631-638页

作者： Wakshum shiferaw Sebsebe Demissew Tamrat Bekele Ermias Aynekulu Wolfgang Pitroff Arba Minch University College of Agricultural SciencesNatural Resources ManagementP.O.Box 21Arba MinchEthiopia Addis Ababa University College of Natural SciencesPlant Biology and Biodiversity ManagementP.O.Box 3434Addis AbabaEthiopia The World Agroforestry Centre(ICRAF) UN AvenueP.O.Box 30677NairobiKenya College of Agriculture Food and Natural ResourcesUniversity of MissouriColumbiaUSA

Woody species within pastures and savannas are often associated with‘resource islands’characterized by higher fertility under canopies *** aims of this study were to evaluate(1)the effects of Prosopis juliflora on some soil physicochemical properties and(2)the impacts of Prosopis invasion on soil *** soil physicochemical analysis,a total of 104 soil samples from Teru and Yalo Districts were *** soil samples were collected from soil depths of 0-15 cm and 15-30 cm in Prosopis invaded and non-invaded open grazing *** of Prosopis had significantly affected soil pH,exchangeable Na^(+),water soluble Ca^(2+)+Mg^(2+),water soluble Na^(+),and exchangeable sodium percentage in Teru and Yalo Districts(p<0.05).The invasion of Prosopis significantly increased soil pH(1.5%),but decreased exchangeable Na^(+)(24.2%),exchangeable sodium percentage(21.6%),and water soluble Ca^(2+)+Mg^(2+)(39.9%)than non-invaded *** content of Prosopis invaded lands was higher by 19%than non-invaded ***,sand content of soil was higher under non-invaded lands by 5.6%than Prosopis invaded *** results indicated that invasion of Prosopis had positive effects on physicochemical properties and thus conducive for cereal crops and forages.

关键词： Phrase(s):invasion Open grazing lands Prosopis Rangelands reclamation Soil properties

Evaluation of soil nutrients under Eucalyptus grandis plantation and adjacent sub-montane rain forest

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Journal of Forestry Research 2010年第4期21卷 457-460,523页

作者： shiferaw Alem Tadesse Woldemariam Jindrich Pavlis Mendel University Faculty of Forestry and Wood technology Environment and Coffee Forest Forum

A study was conducted to evaluate the status of soil nutrients under E. grandis plantation in comparison with that in its adjacent submontane rain forest. Twenty sequare plots, with an area of 20 m×20 m for each, were established in both of *** plantation and its adjacent sub-montane rain forest, independently. Soil samples were collected from each square plot, at five points （at the four comers and at the center） of each plot. The collected soil samples were mixed to make a composite and representative sample for each plot, independently. The analyses were done in a soil laboratory following appropriate methods. The analysis result indicated that there were no significance differences between E. grandis plantation and its adjacent sub-montane rain forest in the level of major soil nutrients （total N, available P, exchangeable K, Ca and Mg）, pH and total carbon of soils （p 〈 0.05）. There were significance differences between two sites of forest soils in percentage of clay particles, and exchangeable Na content. E. grandis plantation was found improving soil nutrients and total carbon as compared with that of its adjacent submontane rain forest.

关键词： Eucalyptus grandis plantation rain forest soil nutrients sub-montane

Relationship between Prosopis juliflora invasion and livelihood diversification in the South Afar region,Northeast Ethiopia

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Regional Sustainability 2020年第1期1卷 82-92页

作者： Wakshum shiferaw Sebsebe Demissew Tamrat Bekele Ermias Aynekulu College of Agricultural Sciences Arba Minch UniversityArba MinchP.O.Box 21Ethiopia College of Natural Sciences Addis Ababa UniversityAddis AbabaP.O.Box 3434Ethiopia The World Agroforestry Centre(ICRAF) UN AvenueNairobiP.O.Box 30677Kenya

This study assessed the effects of Prosopis juliflora invasion on livelihood diversification and evaluated the determinants of livelihood diversification in two districts in the South Afar region of Northeast *** random sampling method,154 households and 2 focus groups composed of 10 individuals were selected from four sites in the two *** relationship between *** invasion and incomes obtained from *** varied across the study *** Awash Fentale District and Amibara District,11.0%and 3.2%of households,respectively,earned income from *** charcoal *** total,14.3%of households were involved in charcoal *** addition,19.9%of households earned income from selling *** pods and wood materials in the two *** the exception of income from *** charcoal production,the sex of households did not affect incomes from other livelihood ***,household educational attainment significantly affected income obtained from vegetables,fruits,and cereal *** householders were engaged in more diverse livelihood activities than female *** the severe invasion of *** on grazing and woodlands in the region is advisable through integrated natural resources,pastoralist participation,and multidisciplinary research strategies.

关键词： Determinant factors Livelihood diversification Household incomes Prosopis juliflora invasion Simpson’s diversification index(SDI)