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Rehabilitation of indigenous browse plant species following exclosure established on communal grazing lands in South Tigray, Ethiopia, and implication for conservation

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Ecological Processes 2019年第1期8卷 530-538页

作者： Tesfay Atsbha Solomon Wayu Nguse Gebretsadkan Tesfay Gebremariam tsgehiwet giday Tigray Agricultural Research Institute Alamata Agriculture Research CenterP.O.Box56AlamataEthiopia

Background:Despite the wide use of indigenous browse plant species,there is almost no information on the rehabilitation of indigenous browse species following area exclosure(AE)established on communal grazing lands(CGL)in Southern *** objectives of this study were to assess the rehabilitation of browse plant species following AE establishment on CGL.A total of 61 and 59 plots of 10×10m2 size were laid down at 50-m intervals along parallel line transects at AE and GCL,*** collected on vegetation attributes were subjected to analysis of t test(unequal variances)using ***:The Shannon diversity index of the browse plant species was 1.25 and 0.81 in AE and CGL,respectively(P<0.001).The overall population structure of browse plant species in the AE shows a reverse J-shaped population curve and“good”regeneration status,which reveals that the future communities may be *** biomass and basal area of browse plant species were significantly higher in the AE than in CGL(P<0.001).After exclusion of grazing,AE was found to have positive effects on diversity and aboveground biomass of browse plant ***:The study gives an understanding of the diversity,the pattern of population and regeneration of the browse plant species,which may help in the management and conservation of the *** results indicate that grazing exclusion is an effective management strategy to restore browse plant *** concluded that the establishment of AE had a positive effect on the rehabilitation of browse plant species diversity and improved population structure and regeneration potentials of degraded grazing ***-term monitoring and evaluation systems will be required to gain an informed understanding of the roles played by area exclosures in the rehabilitation and conservation of browse palnt species diversity.

关键词： Browse Rehabilitation Restoration

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Exclosure land management for restoration of herbaceous species in degraded communal grazing lands in Southern Tigray

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Ecosystem Health and Sustainability 2020年第1期6卷 309-319,308页

作者： Tesfay Atsbha Solomon Wayu Nguse Gebretsadkan tsgehiwet giday Tesfay Gebremariam Tigray Agricultural Research Institute Alamata Agriculture Research CenterP.O.BOX 56AlamataEthiopia

Herbaceous species contribute to the largest proportion of the *** the profound benefits obtained,anthropogenic disturbances are hindering its *** the other hand,to ensure the sustainability of herbaceous species,communities and governments have been putting efforts in managing herbaceous species through the establishment of area exclosure(AE).Thus,the main importance of this research paper is to provide information about the role of AE on the restoration of herbaceous *** objective of this study was to assess the effect of restoration on the herbaceous species following AE established on communal grazing land(CGL).A total of 124 and 73 quadrats of 1×1m^(2) size were laid down at 50 m intervals along parallel transects at AE and CGL,respectively,and data were analyzed by t-test unequal variances using *** displayed higher plant species richness and diversity than the CGL and showed a significant difference(p<0.001).Similarly,the AE had significantly(p<0.001)higher forage biomass than the *** general,herbaceous species diversity index and species richness were significantly(p<0.001)higher in the AE compared to the *** study concluded that effective AE has the potential to enhance the restoration of herbaceous species and hence forage productivity.

关键词： Grazing land land conservation palatable indigenous vegetation area exclosure

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Ultrathin ternary PtNiGa nanowires for enhanced oxygen reduction reaction

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Chinese Chemical Letters 2024年第2期35卷 599-603页

作者： giday Fisseha Yiping Hu Yanan Yu Shaojie Lu Dongsheng Ma Pei Nian Zheng Wang Qin Yue Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering School of Chemistry and Chemical EngineeringNingxia UniversityYinchuan 750021China

Achieving high activity and durability for the oxygen reduction reaction(ORR)with an ultra-low amount of platinum is significant to promote the widespread application of proton exchange membrane fuel cells(PEMFCs).Here we report a new ultrathin(∼1 nm)ternary PtNiGa alloy nanowires(PtNiGa NWs)electrocatalyst,in which the presence of gallium(Ga)enhances the oxidation resistance of platinum(Pt)and nickel(Ni)and suppresses the dissolution of *** mass and specific activities of PtNiGa NWs are about 11.2 and 7.6 times higher than those of commercial Pt/C catalysts for ***,the mass activity of PtNiGa/C NWs nanocatalyst decreased only by 12.8%and largely retained its electrochemical surface area(ECSA)after 10,000 potential cycles,compared with 38%loss of ECSA for commercial Pt/C ***,this work provides a general guideline for preparing ternary alloy electrocatalysts and enhancing the activity and stability of the cathode ORR reaction of PEMFCs.

关键词： Ultrathin nanowires Gallium Oxygen reduction reaction Ternary alloy Durability

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新型核壳AuTi@PtNi纳米催化剂:增强氧还原催化活性及稳定性（英文）

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Chinese Journal of Catalysis 2024年第1期56卷 81-87页

作者： giday Fisseha 于亚楠鲁少杰胡一平周雨岳秦电子科技大学基础与前沿研究院清华四川能源互联网研究院

质子交换膜燃料电池（PEMFCs）将化学燃料转化为电能,具有能量转换效率高、清洁、零排放等特点,被认为是未来重要的能源利用装置.与阳极发生的氢氧化反应相比,阴极发生的氧还原反应（ORR）是动力学缓慢的过程,严重阻碍了燃料电池的广泛... 详细信息

质子交换膜燃料电池（PEMFCs）将化学燃料转化为电能,具有能量转换效率高、清洁、零排放等特点,被认为是未来重要的能源利用装置.与阳极发生的氢氧化反应相比,阴极发生的氧还原反应（ORR）是动力学缓慢的过程,严重阻碍了燃料电池的广泛应用,因此迫切需要开发高活性的电催化剂来降低其电化学过电位,提高反应动力学.铂基纳米晶是氧还原反应有效的电催化剂,但存在成本高、储量少且耐用性差等问题.将铂（Pt）与过渡金属（Fe, Co, Ni等）合金化可以提升催化活性,且最外层有序的Pt原子层可以有效地避免过渡金属的腐蚀溶解,同时,利用金（Au）与Pt基合金形成核壳结构可以有效地降低催化剂成本,同时增强稳定性.然而,在以Au作为核时,很难通过退火处理获得富含Pt层的核壳催化剂.本文利用钛（Ti）原子与Au原子合金化后的协同作用,成功地制备了核壳AuTi@PtNi氧还原催化剂.由于Ti与Au的强相互作用,使得该催化剂即使经高温退火处理,依旧可以使Au保持在内部,同时可以获得富Pt壳层.利用配备有电子能量损失谱的透射电子显微镜及X射线电子能谱对催化剂进行表征,结果表明, Ti的引入可大大提升催化剂的热稳定性.由于具有核壳结构及富Pt的PtNi壳层,退火后的Au Ti@PtNi-400催化剂在0.9 V（RHE）时的质量比活性(5.26 AmgPt-1)和面积比活性(2.72 mAcm-2)分别是商业化Pt/C催化剂的19.26倍和9.84倍.另外, AuTi@PtNi-400催化剂在20000圈循环测试后质量活性衰减不到10%,稳定性好于商业化Pt/C催化剂和未经过退火的AuTi@PtNi催化剂.进一步对AuTi@PtNi-400进行电催化测试,结果表明,在功率密度达到0.61 Wcm-2的同时可产生1.31 Acm-2的电流密度,该结果优于商业化Pt(1.05 Acm-2和0.34Wcm-2)以及Ti-Au@PtNi/C (1.25 Acm-2和0.62 Wcm-2),峰值功率密度高达0.80 Wcm-2,这表明所制备的Ti-Au@PtNi/C-400催化剂不仅在三电极体系中具有较好的性能,在电堆测试中也展现出高性能,可以较大地满足和促进燃料电池的发展和应用.综上所述,对于燃料电池阴极催化剂,可结合形貌工程及协调作用,制备出低成本高性能的ORR催化剂,为燃料电池的进一步应用提供新思路.

关键词：钛掺杂富铂层热处理氧化还原反应核壳结构

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Ethnobotanical survey of antimalarial plants in Awash-Fentale District of Afar Region of Ethiopia and in vivo evaluation of selected ones against Plasmodium berghei

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Asian Pacific Journal of Tropical Biomedicine 2018年第1期8卷 73-78页

作者： Nega Alelign Mirutse giday Tilahun Teklehaymanot Abebe Animut Department of Biology Faculty of Science Addis Ababa University Aklilu Lemma Institute of Pathobiology Addis Ababa University

Objective: To document plants used in traditional treatment of malaria in the Awash-Fentale District, the Afar Region of Ethiopia, and to evaluate antimalarial activity of selected ones against Plasmodium berghei in mice. Methods: Semi-structured interviews were carried out with purposively selected informants in the District to gather information on plants used in the traditional treatment of malaria. Standard procedures were used to investigate acute toxicity and a four-day suppressive effect of crude aqueous and ethanol extracts of the leaves of the two most frequently cited plants [Aloe trichosantha(A. trichosantha) and Cadaba rotundifolia(C. rotundifolia)] against Plasmodium berghei in Swiss albino mice. Results: The informants cited a total of 17 plants used in the traditional treatment of malaria in Awash-Fentale District. Plant parts were prepared as infusions or decoctions. Leaf was the most commonly cited(44%) plant part, followed by stem(22%). Shrubs were the most frequently cited(63%) medicine source followed by trees(21%). Of the 17 plants, C. rotundifolia and A. trichosantha were the most frequently mentioned plants in the district. Ethanol extracts of the leaves of C. rotundifolia and A. trichosantha suppressed P. berghei parasitaemia significantly accounting for 53.73% and 49.07%, respectively at 900 mg/kg. The plants were found to be non-toxic up to a dose of 1 500 mg/kg. Conclusions: Seventeen plant species were reported to be used for treatment of malaria in the Awash Fentale Distinct, among which A. trichosantha and C. rotundifolia were the most preferred ones. P. berghei suppressive activity of these plants may partly explain their common use in the community.

关键词： Aloe trichosantha Cadaba rotundifolia Antimalarial activity Awash-Fentale District Ethiopia

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Laboratory assessment of the molluscicidal and cercariacidal activities of Balanites aegyptiaca

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Asian Pacific Journal of Tropical Biomedicine 2013年第8期3卷 657-662页

作者： Eshetu Molla Mirutse giday Berhanu Erko Dilla University P.O. Box 419DillaEthiopia Aklilu Lemma Institute of Pathobiology Addis Ababa UniversityP.O. Box 1176Addis AbabaEthiopia

Objective:To assess the molluscicidal and cercariacidal activities of aqueous extracts of Balanites aegyptiaca(***)against EthiopianBiomphalaria pfeifferi(***),Lymnaea natalensis(***)and Schistosoma mansoni(***)***:Extracts of seeds,endocarp,mesocarp,and fruit of *** tested for their activities against *** cercariacidal activity of the seeds of the plant was also evaluated *** were carried out following the methods recommended by *** mortalities were compared between each plant part and snail species,and LC50and LC90values for the plant parts tested were *** cercariacidal activity of the plant was assessed by exposing the mice to the cercariae pre-exposed to aqueous extract of ***:For the molluscicidal activities of seeds,endocarp,mesocarp and whole fruit,the LC50values *** 56.32,77.53,65.51 and 66.63 mg/L,respectively,while the respective LC90values were 77.70,120.04,89.50 and 97.55 mg/***,the LC50values for the seeds,endocarp,mesocarp and whole fruit *** 80.33,92.61,83.52 and 87.84mg/L,respectively,while the respective LC90values were 102.30,138.21,115.42 and 127.69 mg/*** found to be more susceptible *** cercariae exposed to 15 mg/L of extract of seeds were incapable of infecting *** mean egg load of tissue was reduced in mice infected with the cercariae exposed to 5 and 10 mg/L of the ***:The aqueous extracts of different parts *** reasonable molluscicidal activity ***,as well as cercariacidal activity ***,comprehensive laboratory evaluation is recommended prior to field tests of the plant parts since their impact on other aquatic biota is not known.

关键词： Balanites aegyptiaca Molluscicide Biomphalaria pfeifferi Lymnaea natalensis Cercariacide Schistosoma mansoni

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A combination of climate,tree diversity and local human disturbance determine the stability of dry Afromontane forests

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Forest Ecosystems 2021年第2期8卷 207-222页

作者： Hadgu Hishe Louis Oosterlynck Kidane giday Wanda De Keersmaecker Ben Somers Bart Muys KU Leuven Department of Earth and Environmental SciencesDivision ForestNature and LandscapeCelestijnenlaan 200EP.O.Box 24113001 LeuvenBelgium Department of Land Resource Management and Environmental Protection Mekelle UniversityCollege of Dryland Agriculture and Natural ResourcesP.O.Box 231MekelleTigrayEthiopia Laboratory of Geo-Information Science and Remote Sensing Wageningen University6708 PB WageningenThe Netherlands

Background:Anthropogenic disturbances are increasingly affecting the vitality of tropical dry *** future condition of this important biome will depend on its capability to resist and recover from these *** far,the temporal stability of dryland forests is rarely studied,even though identifying the important factors associated with the stability of the dryland forests could serve as a basis for forest management and ***:In a degraded dry Afromontane forest in northern Ethiopia,we explored remote sensing derived indicators of forest stability,using MODIS satellite derived NDVI time series from 2001 to *** and resistance were measured using the anomalies(remainders)after time series decomposition into seasonality,trend and remainder *** stability was calculated using the integral of the undecomposed NDVI *** NDVI derived stability indicators were then related to environmental factors of climate,topography,soil,tree species diversity,and local human disturbance,obtained from a systematic grid of field inventory plots,using boosted regression trees in ***:Resilience and resistance were adequately predicted by these factors with an R^(2) of 0.67 and 0.48,respectively,but the model for growth stability was *** of the wettest month,distance from settlements and slope were the most important factors associated with resilience,explaining 51%of the ***,temperature seasonality and humus accumulation were the significant factors associated with the resistance of the forest,explaining 61%of the overall effect.A positive effect of tree diversity on resilience was also important,except that the impact of species evenness declined above a threshold value of 0.70,indicating that perfect evenness reduced the resilience of the *** of the wettest month was the most important factor explaining 43.52%of the growth stability ***:A combination of clima

关键词： Climate Dryland Disturbance Restoration Tigray Growth stability Biodiversity function

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Antibacterial activities of selected medicinal plants in traditional treatment of human wounds in Ethiopia

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Asian Pacific Journal of Tropical Biomedicine 2011年第5期1卷 370-375页

作者： Biruhalem Taye Mirutse giday Abebe Animut Jemal Seid Aklilu Lemma Institute of Pathobiology P.O.BoxAddis Ababa University ALERT Hospital Addis AbabaEthiopia

Objective:To evaluate the activity of selected Ethiopian medicinal plants traditionally used for wound treatment against wound-causing ***:Samples of medicinal plants(Achyranthes aspera,Brucea antidysenteriea,Datura stramonium,Croton macrostachyus,Acokanthera xchimperi.,Phytolacca dodecandra,Milhttia ferruginea,and Solanum incanum)were extracted using absolute methanol and water and tested for their antimicrobial activities against clinical isolates and standard strains of wound-causing bacteria using agar well diffusion and micro titer plate ***:Most of the plant extracts had antibacterial activities,among which Acokanthera schimperi and Brucea antidysenteriea inhibited growth of 100%and 35%of the test organisms,*** extracts had higher activities compared with their corresponding aqueous *** most susceptible organism to the extracts was Streptococcus pyogens while the most resistant were Escherichia coli and Proteus ***:This finding justifies the use of the plants in wound healing and their potential activity against woundcausing *** toxicity level and antimicrobial activity with different extraction solvents should further be studied to use them as sources and templates for the synthesis of drugs to control wound and other disease-causing bacteria.

关键词： Antibacterial activity Medicinal plants Human wounds Ethiopia Agar well diffusion Micro titer plate Plant extracts

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种求解非线性无约束优化问题的充分下降的共轭梯度法

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运筹学学报 2018年第3期22卷 59-68页

作者： Tsegay giday Woldu 张海斌张鑫张芳北京工业大学应用数理学院北京100124

共轭梯度法是一类具有广泛应用的求解大规模无约束优化问题的方法.提出了一种新的非线性共轭梯度(CG)法,理论分析显示新算法在多种线搜索条件下具有充分下降性.进一步证明了新CG算法的全局收敛性定理.最后,进行了大量数值实验,其结果表... 详细信息

共轭梯度法是一类具有广泛应用的求解大规模无约束优化问题的方法.提出了一种新的非线性共轭梯度(CG)法,理论分析显示新算法在多种线搜索条件下具有充分下降性.进一步证明了新CG算法的全局收敛性定理.最后,进行了大量数值实验,其结果表明与传统的几类CG方法相比,新算法具有更为高效的计算性能.

关键词：无约束优化问题非线性共轭梯度法充分下降性全局收敛性

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A Scaled Conjugate Gradient Method Based on New BFGS Secant Equation with Modified Nonmonotone Line Search

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American Journal of Computational Mathematics 2020年第1期10卷 1-22页

作者： Tsegay giday Woldu Haibin Zhang Yemane Hailu Fissuh Department of Applied Mathematics Beijing University of Technology Beijing China Department of Statistics Aksum University Aksum Ethiopia

In this paper, we provide and analyze a new scaled conjugate gradient method and its performance, based on the modified secant equation of the Broyden-Fletcher-Goldfarb-Shanno (BFGS) method and on a new modified nonmonotone line search technique. The method incorporates the modified BFGS secant equation in an effort to include the second order information of the objective function. The new secant equation has both gradient and function value information, and its update formula inherits the positive definiteness of Hessian approximation for general convex function. In order to improve the likelihood of finding a global optimal solution, we introduce a new modified nonmonotone line search technique. It is shown that, for nonsmooth convex problems, the proposed algorithm is globally convergent. Numerical results show that this new scaled conjugate gradient algorithm is promising and efficient for solving not only convex but also some large scale nonsmooth nonconvex problems in the sense of the Dolan-Moré performance profiles.

关键词： Conjugate Gradient Method BFGS Method Modified Secant Equation Nonmonotone Line Search Nonsmooth Optimization

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