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Three-dimensional coherent X-ray diffraction imaging via deep convolutional neural networks

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npj Computational Materials 2021年第1期7卷 1592-1599页

作者： Longlong Wu Shinjae Yoo Ana F.Suzana Tadesse a.assefa Jiecheng Diao Ross J.Harder Wonsuk Cha Ian K.Robinson Computational Science Initiative Brookhaven National LaboratoryUptonNYUSA Condensed Matter Physics and Materials Science Department Brookhaven National LaboratoryUptonNYUSA Stanford Institute for Materials and Energy Sciences SLAC National Accelerator LaboratoryCaliforniaUSA London Centre for Nanotechnology University College LondonLondonUK Advanced Photon Source ArgonneILUSA

As a critical component of coherent X-ray diffraction imaging(CDI),phase retrieval has been extensively applied in X-ray structural science to recover the 3D morphological information inside measured particles.Despite meeting all the oversampling requirements of Sayre and Shannon,current phase retrieval approaches still have trouble achieving a unique inversion of experimental data in the presence of noise.Here,we propose to overcome this limitation by incorporating a 3D Machine Learning(ML)model combining(optional)supervised learning with transfer learning.The trained ML model can rapidly provide an immediate result with high accuracy which could benefit real-time experiments,and the predicted result can be further refined with transfer learning.More significantly,the proposed ML model can be used without any prior training to learn the missing phases of an image based on minimization of an appropriate‘loss function’alone.We demonstrate significantly improved performance with experimental Bragg CDI data over traditional iterative phase retrieval algorithms.

关键词： coherent convolution overcome

Influence of preterm birth on the association between gestational diabetes mellitus and childhood developmental vulnerability:a causal mediation analysis

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World Journal of Pediatrics 2024年第1期20卷 54-63页

作者： Bereket Duko Amanuel Tesfay Gebremedhin Gizachew assefa Tessema Gavin Pereira Australian Centre for Precision Health UniSA Clinical and Health SciencesUniversity of South AustraliaNorth TerraceAdelaideSA5000Australia Curtin School of Population Health Faculty of Health SciencesCurtin UniversityKent StreetBentleyWA 6102Australia enAble Institute Curtin UniversityKent StreetBentleyWA6102Australia Centre for Fertility and Health(CeFH) Norwegian Institute of Public HealthOsloNorway

Background Epidemiological studies examining the direct and indirect effects of gestational diabetes mellitus(GDM)on offspring early childhood developmental vulnerability are lacking.Therefore,the aims of this study were to estimate the direct and indirect effects of GDM(through preterm birth)on early childhood developmental vulnerability.Methods We conducted a retrospective population-based cohort study on the association between gestational diabetes mellitus and early childhood developmental vulnerability in children born in Western Australia(WA)using maternal,infant and birth records from the Midwives Notification,Hospitalizations,Developmental Anomalies,and the Australian Early Development Census(AEDC)databases.We used two aggregated outcome measures:developmentally vulnerable on at least one AEDC domain(DV1)and developmentally vulnerable on at least two AEDC domains(DV2).Causal mediation analysis was applied to estimate the natural direct(NDE),indirect(NIE),and total(TE)effects as relative risks(RR).Results In the whole cohort(n=64,356),approximately 22%were classified as DV1 and 11%as DV2 on AEDC domains.Estimates of the natural direct effect suggested that children exposed to GDM were more likely to be classified as DV1(RR=1.20,95%CI:1.10-1.31)and DV2(RR=1.34,95%CI:1.19-1.50)after adjusting for potential confounders.About 6%and 4%of the effect of GDM on early childhood developmental vulnerability was mediated by preterm birth for DV1 and DV2,respectively.Conclusion Children exposed to gestational diabetes mellitus were more likely to be developmentally vulnerable in one or more AEDC domains.The biological mechanism for these associations is not well explained by mediation through preterm birth.

关键词： Child development Causal mediation analysis Gestational diabetes mellitus Offspring

Characteristics of soil quality attributes under different agroecosystems and its implications for agriculture in the Choke Mountain watershed in Ethiopia

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Frontiers of Agricultural Science and Engineering 2024年第2期11卷 303-313页

作者： Demeku MESFIN Engdawork assefa Belay SIMANE College of Development Studies Center for Environment and DevelopmentAddis Ababa UniversityAddis Ababa 1000Ethiopia College of Social Science and Humanities Department of Geography and Environmental StudiesWolaita Sodo UniversityWolaita Sodo 4620Ethiopia

Awareness of how soil properties vary over agroecosystems(AES) is essential for understanding soil potentials and improving site-specific agricultural management strategies for a sustainable ecosystem. This study examined the characteristics of soil quality attributes and implications for agriculture in the Choke Mountain watershed in Ethiopia. Forty-seven composite soil samples(0–20 cm deep) were collected from lowland and valley fragmented(AES 1),midland plain with black soil(AES 2), midland plain with brown soil(AES 3),sloppy midland land(AES 4), and hilly and mountainous highlands(AES 5).Ten of 15 soil quality properties were significant(P < 0.05 or 0.01), including silt, exchangeable bases, cation exchange capacity, percent base saturation,p H, organic matter, total nitrogen and available phosphorous(P) across the five AES. However, all properties were variable with coefficients of variation from 7%(total porosity) to 169%(available P) across the AES. Although AES 2and 3 are affected by waterlogging and acidity, these two have better prospects for agriculture, but AES 1, 4, and 5 are unsuitable for agriculture because of soil erosion. Therefore, appropriate and applicable soil management strategies, particularly lime application and organic fertilizer, are fundamental to reversing soil acidity and improving soil fertility.

关键词： Agroecosystem Choke Mountain watershed coefficients of variation Ethiopia soil quality indicator

A comparative study of acidic,basic,and reactive dyes adsorption from aqueous solution onto kaolin adsorbent:Effect of operating parameters,isotherms,kinetics,and thermodynamics

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Emerging Contaminants 2022年第1期8卷 59-74页

作者： Tadele assefa Aragaw Adugna Nigatu Alene Faculty of Chemical and Food Engineering Bahir Dar Institute of TechnologyBahir Dar UniversityBahir DarEthiopia

Various studies were reported for the evaluation of the adsorption performance of kaolin clay using single dye types.This paper aimed to evaluate the comparative adsorption capacity of prepared adsorbents from Ethiopian kaolin for different dye types(Basic Yellow 28(BY 28),Congo Red(CR),and Reactive Red 120(RR 120)).Because different dye classes may have a significant impact on the removal efficiency by the prepared adsorbent.Moreover,we intended to investigate the interaction effect of adsorbent-sorbate in the adsorption phenomenon for the three different class dyes.The adsorbents from kaolin clay were prepared via mechanical treatment,beneficiation,and calcination(700℃).The effect of operating parameters(pH,adsorbent dose,contact time,dye concentration,and adsorption temperature)was evaluated.before and after adsorption of the adsorbents were characterized using FTIR spectroscopy.Furthermore,adsorption isotherm,kinetic models,and the thermodynamic processes in the adsorption phenomenon were computed.The percentage removal efficiency of dyes was recorded as 92.08%,88.63%,and 73.33%for BY 28,CR,and RR 120 dyes,respectively at the experimental condition:adsorbent dosage=1 g/100 mL,solution pH=9(BY 28),and pH=3(CR,and RR 120),contact time=60 min,initial dyes concentrations=20 mg/L,and temperature=30℃.The adsorption of adsorbates onto kaolin adsorbents was well fitted with pseudo-second-order kinetics and Langmuir isotherm models.The thermodynamic parameters indicate that the adsorption process is spontaneous and exothermic for all dyes.The comparative percentage removal of,with the same operational parameters and kaolin adsorbent,was recorded as BY 28>CR>RR120 resulting from their surface charge and molecular size/structure dyes properties.We confirm that the adsorption at each operational parameter and peak intensity of FTIR spectra,before and after adsorption,revealed that the different dye types have varied removal efficiency onto the prepared kaolin adsorbent.This is due to that being dominantly influenced by t

关键词： Beneficiated adsorbent Different class dyes Adsorption Operational parameters Removal efficiency Electrostatic interaction

埃塞俄比亚南部公立医院护士和助产士对关怀行为的感知及关联因素

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International Journal of Nursing Sciences 2022年第4期9卷 490-495,I0002页

作者： Abreham assefa Dinkalem Getahun Nathan Desalegn Etenesh Kefelew Wondwosen Molla Dawit Getachew assefa Mesfin Abebe Leku General Hospital Sidama Regional Health BureauHawasaEthiopia School of Nursing College of Medicine and Health SciencesArba Minch UniversityArba MinchEthiopia School of Public Health College of Medicine and Health SciencesArba Minch UniversityArba MinchEthiopia Department of Midwifery College of Medicine and Health SciencesDilla UniversityDillaEthiopia Department of Nursing College of Medicine and Health SciencesDilla UniversityDillaEthiopia

目的本研究旨在评估在埃塞俄比亚哈瓦萨希达莫地区公立医院提供孕产保健服务的护士和助产士对关怀行为的感知及相关因素。方法采用横断面研究设计,对该地区公立医院产科病房的269名护士和助产士进行抽样调查。使用自填问卷收集数据。采... 详细信息

目的本研究旨在评估在埃塞俄比亚哈瓦萨希达莫地区公立医院提供孕产保健服务的护士和助产士对关怀行为的感知及相关因素。方法采用横断面研究设计,对该地区公立医院产科病房的269名护士和助产士进行抽样调查。使用自填问卷收集数据。采用多变量logistic回归分析确定与护士和助产士感知关怀行为关联的因素。结果共261名护士和助产士参与此项调查。依据调查获得的平均得分,将护士和助产士感知关怀行为分为较高和较低水平。本研究中,75.1%(196/261)的护士和助产士感知关怀行为水平较高。调查对象的年龄、职业满意度、个人满意度、助产士/护士-医生关系和工作量与他们的感知关怀行水平存在关联。结论评估护士和助产士的感知关怀行水平和关联因素对提供高质量护理和助产干预至关重要。建议通过减轻护士和助产士的过高工作负荷,改善护士/助产士与医生的关系,并通过表彰和奖励提高他们的工作满意度,来营造积极的关怀氛围,以改善护士和助产士的关怀行为。

关键词：关怀行为埃塞俄比亚孕产保健护理感知

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 years.However,the successes of these practices have been quite limited and the main factors affecting these practices have not been examined in detail.This 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 basin.Data were collected from 304 household heads in six sub catchments across different topographic settings using household interview.Focus groups discussions,key informant interviews and transect walk observations were also used.Descriptive statistics and econometric models such as,multivariate and ordered probit were used to analyze the data.The results revealed that the majority of households (82.6 percent) used at least one of the six practices considered in this study.Soil bund,grass strip cultivation with soil bund and compost were the major watershed management practices adopted by farmers.Adoption rate and intensity of adoption were better for program participants and in upper and middle topographic settings.The 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 practices.Hence,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

Determinants of farmers’ adoption of land management practices in Gelana subwatershed of Northern highlands of Ethiopia

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Ecological Processes 2017年第1期6卷 192-202页

作者： Birhan Asmame Miheretu assefa Abegaz Yimer Department of Geography and Environmental Studies Wollo UniversityP.O.Box:1145DessieEthiopia Department of Geography and Environmental Studies Addis Ababa UniversityAddis AbabaEthiopia

Introduction:Soil erosion is the major environmental problem in Ethiopia.In response to this problem,the country has been in continuous struggle to adopt land management practices.Therefore,the objective of this study was to investigate the determinants of farmers’adoption of land management practice in the Gelana sub-watershed,Northern highlands of Ethiopia.Methods:The data was collected from 176 randomly selected farming households using a survey questionnaire and was analyzed using multinomial logit model(MNL).Results:The results showed that education,family size,slope of the plot,tenure security,training,access to farm credit and extension service positively and significantly affect adoption of land management practices while age has a negative and significant influence on adoption.Conclusions:The findings suggest that improving farmers’education status and increase the availability of credit to reduce poverty and increase income would enhance the adoption of land management practices.

关键词： Land management Adoption Multinomial logit model Ethiopia

The impacts of land-use and land-cover change on wetland ecosystem service values in peri-urban and urban area of Bahir Dar City, Upper Blue Nile Basin, Northwestern Ethiopia

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Ecological Processes 2021年第1期10卷 510-527页

作者： Workiyie Worie assefa Belachew Getnet Eneyew Ayalew Wondie Department of Biology College of ScienceBlue Nile Water InstituteBahir Dar UniversityP.O.Box 79Bahir DarEthiopia. College of Social Science Blue Nile Water InstituteBahir Dar UniversityP.O.Box 79Bahir DarEthiopia. School of Fisheries and Wildlife College of Agriculture and Environmental SciencesBahir Dar UniversityP.O.Box 79Bahir DarEthiopia.

Background:Even though wetlands are essential in enhancing water quality and providing recreation and entertainment opportunities in urban areas,their values are overlooked by the decision-makers.Underestimation of the economic value of wetland ecosystem services contributes to their continuing deterioration and inevitable loss.Investigating the changes in ecosystem service values(ESV)can provide crucial information for decision-making.This study,therefore,analyzes the temporal and spatial land-use/land-cover(LULC)change patterns over 35 years(1984–2019)intending to evaluate its impact on wetland ecosystem service values in Bahir Dar City,Ethiopia.Estimation and change analyses of ESVs were conducted by employing ArcGIS using LULC inputs of the year 1984,1994,2004,2014,and 2019 with their corresponding global value coefficients that were developed earlier and our own modified value coefficients for the studied landscape.Results:The results showed that wetlands and water bodies of the city and its peripheries had decreased by 75.71%(−1618 ha)within 35 years,while built-up area increased by 216.24%(+2599 ha).Cultivated land had increased slightly from 1984 to 1994 and then gradually declined since 1994.Changes in LULC had resulted in a decline of the total ESV.The total ESV had decreased from USD 29.73×10^(6) to USD 20.84×10^(6) in 35 years.This indicates the loss of nearly USD 8.9×10^(6) ESV from 1984 to 2019.A sensitivity analysis suggested the robustness of ESV estimation in the study area.All individual ecosystem services experienced a negative change.However,a greater reduction in ESV was observed for services such as water regulation,waste treatment,and habitats for maintaining biodiversity.The expansion of built-up area of Bahir Dar City was the major factor that contributed to the loss of ESV provided by wetlands.Conclusions:The loss of ESV resulting in LULC changes has a negative implication on local climate,waste management,and the livelihoods of the poor community.Thus,interventions should be made for th

关键词： Ecosystem service Economic valuation Land use/land cover Landscape change Urban wetland

Factors affecting farmers’participation in watershed management programs in the Northeastern highlands of Ethiopia:a case study in the Teleyayen sub-watershed

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Ecological Processes 2018年第1期7卷 137-151页

作者： Alem-meta.assefa Agidew K.N.Singh Department of Geography and Environmental Studies Wollo UniversityP.O.Box 1145DessieEthiopia Department of Geography and Environmental Studies Addis Ababa UniversityP.O.Box 1176Addis AbabaEthiopia

Introduction:This study investigated factors affecting farmers’participation in watershed management programs in the Northeastern highlands of Ethiopia by taking the Teleyayen sub-watershed as a case study.Data were collected from 215 farm households which were selected from the four villages using a multistage sampling procedure,involving a combination of purposive and random sampling.Data were gathered using a structured survey questionnaire,focus group discussion,and key informant interviews.Descriptive analysis,Pearson correlation analysis,and regression analysis were employed to analyze the data.Results:Findings of this study showed that farmer’s perception has a strong positive correlation(r=0.612,P=0.000)with the farmer’s decision to participate in the watershed management programs followed by government support(r=0.163,P=0.017),while the slope of the farmland and the gender of the household head have shown significant and negative associations.The binary logistic regression analysis also revealed that six independent variables were significant in explaining the factors affecting the farmers’decision to participate in watershed management programs.These variables were land redistribution,gender,agricultural labor force,extension service,farm size,and slope.Of these,land redistribution,gender,agricultural labor force,extension service,and slope of the farmland indicated a negative influence,while farm size of a household exerted a positive impact.The study also examined the role of discrete variables in explaining variations of variables in affecting the farmers’decision to participate in the programs.Thus,two variables found to be significant.These variables are the gender of the household head and land tenure security.Accordingly,the chi-square result of the variable(χ^(2)=9.052)of gender was found to be statistically significant at the 95%level of significance.Similarly,the chi-square result(X^(2)=8.792)of land tenure security was found to be statistically significant at the 95%level of significance.Conc

关键词： Binary logistic regression model Ethiopia Farmers’participation Watershed management