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Modeling the distribution of Aloe ankoberensis and A. debrana under different climate change scenarios in North Shewa Zone, Amhara National Regional State, Ethiopia

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Ecological Processes 2024年第2期 260-278页

作者： Haile Abebe Anteneh Belayneh Desta sintayehu Workneh Dejene Africa Center of Excellence in Climate Smart Agriculture and Biodiversity Conservation Haramaya University School of Biological Sciences and Biotechnology College of Natural and Computational SciencesHaramaya University

Background Aloe ankoberensis M.G. Gilbert & Sebsebe and A. debrana Christian are Ethiopian endemic species currently classified as endangered and least concern, respectively under International Union for Conservation of Nature(IUCN) categories. Recent studies indicate that climate change is anticipated to significantly influence the distribution of plant species. Therefore, this study aimed to model the distribution of A. ankoberensis and A. debrana under different climate change scenarios in the North Shewa Zone, Amhara National Regional State of Ethiopia. Thirty-six and 397 georeferenced presence points for A. ankoberensis and A. debrana, respectively, and 12 environmental variables were used to simulate their current and future distributions. The ensemble model approach was used to examine the current and future(2050 and 2070) climatic suitability for both species under three shared socio-economic pathway(SSP) climate scenarios(SSP 2.6, 4.5 and 8.5).Results The performance of ensemble model was excellent for A. ankoberensis with score of area under curve(AUC) 0.96 and true skill statistics(TSS) 0.88, and good for A. debrana with score of AUC 0.87 and TSS 0.63. The main variables that affected the species' distributions were mean diurnal range of temperature, annual precipitation, and elevation. According to the model, under the current climate conditions, 98.32%, 1.01%, 0.52%, and 0.15% were not suitable, lowly, moderately, and highly suitable areas, respectively for A. ankoberensis, and 63.89%, 23.35%, 12.54%, and 0.21% were not suitable, lowly, moderately and highly suitable areas, respectively for A. debrana. Under future climate scenarios, suitable habitats of these species could shrink. In addition, under all climate change scenarios, it is anticipated that highly suitable areas for both species and moderately suitable areas for A. ankoberensis will be lost completely in the future unless crucial interventions are done on *** The results indicat

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Evolution of drought and flood events on the Qinghai-Tibet Plateau and key issues for response

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Science China Earth Sciences 2023年第11期66卷 2514-2529页

作者： Jie LU Shu XU Tianling QIN Xin HE Denghua YAN Cheng ZHANG sintayehu A.ABEBE State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing 100038China Yinshanbeilu National Field Research Station of Steppe Eco-hydrological System China Institute of Water Resources and Hydropower ResearchHohhot 010020China Hydraulic and Water Resources Engineering Department Debre Markos University Institute of TechnologyDebre Markos 999047Ethiopia

The Qinghai-Tibet Plateau is a climate-sensitive *** characteristics of drought and flood events in this region are significantly different as compared to other areas in the country,which could potentially induce a series of water security,ecological and environmental *** is urgent that innovative theories and methods for estimation of drought and flood disasters as well as their adaptive regulations are *** on extensive literature review,this paper identifies new situations of the evolution of drought and flood events on the Qinghai-Tibet Plateau,and analyzes the research progress in terms of monitoring and simulation,forecasting and early warning,risk prevention and emergency *** study found that there were problems such as insufficient integration of multi-source data,low accuracy of forecasting and early warning,unclear driving mechanisms of drought and flood disaster chains,and lack of targeted risk prevention and regulation *** this basis,future research priorities are proposed,and the possible research and development paths are elaborated,including the evolution law of drought and flood on the Qinghai-Tibet Plateau,the coincidence characteristics of drought and flood from the perspective of a water resources system,prediction and early warning of drought and flood coupled with numerical simulation and knowledge mining,identification of risk blocking points of drought and flood disaster chain and the adaptive ***,the paper will provide technical support for preventing flood and drought disasters,water resources protection,ecological restoration and climate change adaptation on the Qinghai-Tibet Plateau.

关键词： Drought and flood evolution Monitoring and simulation Prediction and early warning Risk prevention and emergency response Qinghai-Tibet Plateau

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Role of phase fluctuation and dephasing in the enhancing continuous variable entanglement of a two-photon coherent beat laser

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Chinese Physics B 2012年第1期21卷 210-221页

作者： sintayehu Tesfa Max Planck Institute for the Physics of Complex Systems Nthnitzer Str.3801187 DresdenGermany Physics DepartmentDilla UniversityP.O.Box 419DillaEthiopia

A steady state analysis of the nonclassical features and statistical properties of the cavity radiation of a two- photon coherent beat laser is presented. Results show that the degree of two-mode squeezing, detectable entanglement and intensity of the cavity radiation can increase with the deviation of the phase fluctuations of the laser employed in preparing the atoms, but decrease with the increasing rate at which the induced coherence superposition decays. Although it is found that varying the phase fluctuations and dephasing can lead to modification in the quantum features and statistical properties of the radiation, it does not alter the similarity in the nature of the degree of entanglement detectable by the criteria following from Duan-Giedke-Cirac Zoller and logarithmic negativity in a perceivable manner. Since the intensity and quantum features can be readily enhanced, this system is expected to be a viable source of a strong robust entangled （squeezed） light under various conditions. Moreover, comparison of the mean number of photon pairs with intensity difference shows that the chance of inciting a two-photon process can be enhanced by changing the rate of dephasing and phase fluctuations.

关键词： coherent beat laser phase fluctuations dephasing entanglement

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Impact of climate change on biodiversity and associated key ecosystem services in Africa:a systematic review

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Ecosystem Health and Sustainability 2018年第9期4卷 1-16页

作者： Dejene W.sintayehu College of Agriculture and Environmental Sciences Haramaya UniversityDire DawaEthiopia

Introduction:Biodiversity and biodiversity-based ecosystems services are intrinsically dependent on the *** the twentieth century,climate change has posed major threats to biodiversity in Africa,and impacts are expected to increase as climate change continues and perhaps even ***:Our review shows that the multiple components of climate change are projected to affect all levels of biodiversity,from genes over species to biome *** of biodiversity as a result of climate change can alter the structures and functions of African ecological *** a result,the provision of biodiversity-based ecosystem services and the wellbeing of people that rely on these services are being *** particular concerns are“tipping points”where the exceedance of ecosystem thresholds will possibly lead to irreversible shifts of the structure of ecosystems and their *** recent years,climate prediction models have portended continued warming and more frequent extreme weather events across the *** weather-related disturbances such as El Niño will place a premium on biodiversity and biodiversity-based ecosystem services that people rely ***:As biodiversity underlies all goods and services provided by ecosystems that are crucial for human survival and well-being,this paper synthesizes and discusses observed and anticipated impacts of climate change on biodiversity and biodiversity-based ecosystem service provision and livelihoods,and what strategies might be employed to decrease current and future risks on the well-being of human in Africa.

关键词： Agricultural production climate regulation disease regulation provisioning services regulating services tipping points

Farmers' decision to adopt watershed management practices in Gibe basin, southwest Ethiopia

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International Soil and Water Conservation Research 2019年第4期7卷 376-387页

作者： fekadu Mengistu Engdawork Assefa Center for Environment and Development Studies Addis Ababa UniversityAddis AbabaEthiopia Department of Geography and Environmental Studies Debre Berhan UniversityDebre BerhanEthiopia

Watershed management practices have been implemented to avert land degradation and to enhance people's livelihoods in the highlands of Ethiopia for several ***,the successes of these practices have been quite limited and the main factors affecting these practices have not been examined in *** study intended to investigate rates and intensities of adoption of watershed management practices and to determine the main factors affecting farmers' adoption decisions in the upper Gibe *** were collected from 304 household heads in six sub catchments across different topographic settings using household *** groups discussions,key informant interviews and transect walk observations were also *** statistics and econometric models such as,multivariate and ordered probit were used to analyze the *** results revealed that the majority of households (82.6 percent) used at least one of the six practices considered in this *** bund,grass strip cultivation with soil bund and compost were the major watershed management practices adopted by *** rate and intensity of adoption were better for program participants and in upper and middle topographic *** results of the multivariate and ordered probit analysis indicated that household size,extension services,credit services,training services and perception of soil erosion had positive significant relationship with both rate and intensity of adoption of most ***,policy makers and planners need to consider labor,knowledge and awareness,and capital intensive nature of the practices for the up scaling planning and implementations of watershed intervention technologies.

关键词： Watershed management practices Farmers' decision Adoption Determinants Gibe river basin

Factors associated with diabetic retinopathy screening and regular eye checkup practice among diabetic patients attending Felege Hiwot Specialized Hospital

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International Journal of Ophthalmology(English edition) 2022年第11期15卷 1829-1836页

作者： Sofonias Addis fekadu Mohamed Abdu Seid Yonas Akalu Yibeltal Yismaw Gela Mengistie Diress Mihret Getnet Baye Dagnew Yitayeh Belsti Department of Optometry College of Medicine and Health SciencesUniversity of GondarGondar P.O.BOX 196Ethiopia Unit of Human Physiology Department of Biomedical ScienceCollege of Health SciencesDebre Tabor UniversityDebre Tabor P.O.BOX 272Ethiopia Department of Human Physiology School of MedicineCollege of Medicine and Health SciencesUniversity of GondarGondar P.O.BOX 196Ethiopia

AIM: To identify associated factors of diabetic retinopathy(DR) screening and ey e check-up practice among diabetes mellitus(DM) patients attending Felege Hiwot Specialized ***: An institution-based cross-sectional study was applied from October 4, 2019 to January 12, 2020 at Felege Hiwot Specialized Hospital. A systematic random sampling technique was used to recruit participants and an interviewer-administered questionnaire was employed to collect the data. The collected data were entered into Epi Info version 7 and transposed to SPSS version 24 for statistical analysis. Descriptive statistics were executed and associated factors were identified using binary logistic regression. The strength of association between the independent and the outcome variable was determined using an adjusted odds ratio(AOR) with 95% confidence interval(CI). RESULTS: Four hundred and six participants partake with a response rate of 95.7% and a mean age of 47±11.5y. The magnitude of DR screening was 308(75.9%, 95%CI: 71.5%, 79.8%). Higher educational level(AOR=3.25;95%CI: 1.40, 8.78), good knowledge of DR(AOR=2.50;95%CI: 1.55, 4.46), and family history of DM(AOR=2.15;95%CI: 1.41,3.85) were significantly associated with DR screening. On the other side, rural residence [AOR=3.11(1.89, 5.02)] and undesirable attitudes toward DR [AOR=5.65(3.14, 8.76)] were significantly associated with poor regular eye checkup ***: Most of the participants are screened for DR. Higher education, family history, and good knowledge are associated with DR screening. In addition, rural residence and undesirable attitudes toward DR are associated with regular eye checkup practice.

关键词： diabetic retinopathy eye checkup eye screening diabetes mellitus Ethiopia

The Impact of COVID-19 and FAIR Data Innovation on Distance Education in Africa

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Data Intelligence 2022年第4期4卷 1013-1032,1037,1044,1048页

作者： Akinyinka Tosin Akindele Oladiran Tayo Arulogun Getu Tadele Taye Samson YohannesAmare Mirjam Van Reisen Kibrom fekadu Berhe Balyejusa Gusite Open and Distance Learning Center Ladoke Akintola University of TechnologyP.M.B 4000OgbomosoOyo stateNigeria Kampala International University 210214 KampalaUganda Mekelle University P.O.Box:1871 MekelleEthiopia Virus Outbreak Data Network-Africa and Asia P.O.Box:231 Tilburg University 1310the Netherlands

Prior to the advent of the COVID-19 pandemic, distance education, a mode of education that allows teaching and learning to occur beyond the walls of traditional classrooms using electronic media and online delivery practices, was not widely embraced as a credible alternative mode of delivering education, especially in Africa. In education, the pandemic, and the measures to contain it, created a need for virtual learning/teaching and showcased the potential of distance education. This article explores the potential of distance education with an emphasis on the role played by COVID-19, the technologies employed, and the benefits, as well as how data stewardship can enhance distance education. It also describes how distance education can make learning opportunities available to the less privileged, geographically displaced, dropouts, housewives, and even workers, enabling them to partake in education while being engaged in other productive aspects of life. A case study is provided on the Dutch Organisation for Internationalisation in Education(NUFFIC) Digital Innovation Skills Hub(DISH) project, which is implemented via distance education and targeted towards marginalised individuals such as refugees and displaced persons in Ethiopia,Somalia, and other conflict zones, aiming to provide them with critical and soft skills for remote work for financial remuneration. This case study shows that distance education is the way forward in education today, as it has the capability to reach millions of learners simultaneously, educating, lifting people out of poverty, and increasing productivity and yields, while ensuring that the world is a better place for future generations.

关键词： Distance education COVID-19 Learning management system Instructional design Open learning Online learning Data stewardship

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Distribution and Status of Citrus Leaf and Fruit Spot (Pseudocercospora angolensis) Disease in North Western Ethiopia

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Open Journal of Ecology 2022年第11期12卷 733-741页

作者： Mandefro Aslake Assefa sintayehu Teferi Alem Merkuz Abera College of Agriculture and Environmental Sciences University of Gondar Gondar Ethiopia College of Agriculture and Environmental Sciences Bahir Dar University Bahir Dar Ethiopia

Citrus leaf and fruit spot incited by Pseudocercospora angolensis are one of the most serious production constraints of citrus production in North Western Ethiopia. Disease survey in 10 major citrus growing districts of North-Western Ethiopia was conducted, to indicate the importance of citrus leaf and fruit spot disease and its association with agro-ecological factors. The study was carried out during 2021 and 2022 cropping seasons. And in each cropping season based on availability, a total of 280 citrus trees (200 sweet oranges, 40 mandarins, and 40 lemons) in 20 orchards were randomly assessed. This study result showed that in most of the surveyed areas, leaf and fruit spot were the most prevalent and long-lasting disease of citrus. That is, among 10 studied districts in 8 of them (100%) disease prevalence, (87.25%) incidence and (24.43%) severity were computed. As a result, most citrus growers were practiced uprooting of their citrus trees and replacing them by other fruit crops (Mango and Avocado). Therefore, from the result of the present investigation to provide sustainable citrus fruit productivity and production in areas where citrus leaf and fruit spot disease is predominant and causes a devastating effect, integrated and sustainable citrus leaf and fruit spot disease management practices should be executed. Furthermore, in order to get full illustrates of the importance of the disease, it is useful to conduct related disease surveys in major citrus growing areas of the country.

关键词： Identification Isolation Infection Conidia Survey

Aboveground carbon stock is related to land cover and woody species diversity in tropical ecosystems of Eastern Ethiopia

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Ecological Processes 2020年第1期9卷 423-432页

作者： Dejene W.sintayehu Anteneh Belayneh Nigussie Dechassa College of Agriculture and Environmental Sciences Haramaya UniversityHaramayaEthiopia College of Natural and Computational Sciences Haramaya UniversityHaramayaEthiopia Africa Centre of Excellence for Climate Smart Agriculture and Biodiversity Conservation Haramaya UniversityHaramayaEthiopia

Background:Current theories on biodiversity-carbon sequestration relationship describe biodiversity as an important factor influencing carbon storage,either through complementarity effect or by mass ratio *** far,the expected form of biodiversity-carbon relationships in tropical ecosystems has not been known with ***,we explored the relationship between aboveground carbon stock and different biodiversity measurement indices(i.e.,species richness,species diversity,species evenness,and functional diversity)in different land cover types of Eastern Ethiopia.A total of 48 plots were established using stratified random *** parameters such as diameter at breast height,diameter at stump height,tree height,and species type were ***:We found that the average aboveground carbon stock of the study area is 147.6±17.2 t ha^(−1)(mean,SE)across land cover *** richness,Shannon index,and functional diversity together explained 73.5%,61.4%,58.9%,and 52.0%of the variation in aboveground carbon storage in woodland,riparian forest,bushland,and farmland,*** diversity was a significant predictor explaining the total aboveground carbon stocks(26.7%)across the land cover *** effects of biodiversity on aboveground carbon storage were mediated by functional diversity and presence and dominance of *** shows that both the selection effects and the niche complementarity are important for carbon ***,the impact of functional diversity effects(niche complementarity)was higher than that of functional dominance effects(selection effects).Conclusions:Implementation of protected area-based ecosystem conservation practices in the country seems feasible to mitigate climate change and Reducing Emissions from Deforestation and Forest Degradation(REDD+)programme should emphasize on biodiversity conservation.

关键词： Niche complementarity effect Functional diversity Selection effect Species diversity Species richness