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| 1 | Analysis of environmental factors determining the abundance and diversity of macroinvertebrate taxa in natural wetlands of Southwest Ethiopia显示文摘 | Seid Tiku Mereta Pieter Boets Argaw Ambelu Bayih Asgdom Malu Zewdu Ephrem Addisu Sisay Hailu Endale Menberu Yitbarek Amana Jemal Luc De Meester Peter L.M. Goethals | 2011 | Ecological Informatics2011，，1： | 1 |
| 2 | Development of a multi- metric index based on benthic macroinvertebrates for the as- sessment of natural wetlands in Southwest Ethiopia 显示文摘 | Mereta S T Boets P De Meester L | 2013 | Eco- logical Indicators2013，29，： | 1 |
| 3 | Development of a muhimetric index based on benthic macroinvertebrates for the assessment of natural wetlands in Southwest Ethiopia 显示文摘 | MERETA S T BOETS P MEESTER L D | 2013 | Ecological Indicators2013，29，6： | 1 |
| 4 | Target selection for a small low-thrust mission to near-Earth asteroids显示文摘The preliminary mission design of spacecraft missions to asteroids often involves,in the early phases,the selection of candidate target asteroids.The final result of such an analysis is a list of asteroids,ranked with respect to the necessary propellant to be used,that the spacecraft could potentially reach.In this paper we investigate the sensitivity of the produced asteroids rank to the employed trajectory model in the specific case of a small low-thrust propelled spacecraft beginning its journey from the Sun–Earth L2 Lagrangian point and heading to a rendezvous with some near-Earth asteroid.We consider five increasingly complex trajectory models:impulsive,Lambert,nuclear electric propulsion,nuclear electric propulsion including the Earth’s gravity,solar electric propulsion including the Earth’s gravity and we study the final correlation between the obtained target rankings.We find that the use of a lowthrust trajectory model is of great importance for target selection,since the use of chemical propulsion surrogates leads to favouring less attractive options 19%of times,a percentage that drops to 8%already using a simple nuclear electric propulsion model that neglects the Earth’s gravity effects and thrust dependence on the solar distance.We also find that for the study case considered,a small interplanetary CubeSat named M-ARGO,the inclusion of the Earth’s gravity in the considered dynamics does not affect the target selection significantly. | Alessio Mereta Dario Izzo | 2018 | Astrodynamics2018，2，3： | 0 |
| 5 | Molluscicidal effect of Achyranthes aspera L.(Amaranthaceae)aqueous extract on adult snails of Biomphalaria pfeifferi and Lymnaea natalensis显示文摘Background:Intestinal schistosomiasis caused by Schistosoma mansoni is a wide spread disease in most parts of Ethiopian highlands.Snail control is one major strategy in schistosomiasis control.The use of molluscicidal plant products is becoming interesting due to their environmental friendliness,accessibility and easy application.This research is aimed to evaluate the molluscicidal effect of Achyranthes aspera on Biomphalaria pfeifferi and Lymnaea natalensis snails,which are of great medical and veterinary importance in Ethiopia.Methods:Adult B.pfeifferi snails were exposed to the various concentrations of A.aspera aqueous leaf extract for 24,48 and 72 h.Similarly,adult L.natalensis snails were exposed to the extract for 24 h.Mortality data were analyzed using probit regression model.Phytochemical content of the plant was analyzed using standard screening methods.Results:The plant’s molluscicidal effect on the two snail species was demonstrated.The 24 h LC50 and LC90 values against L.natalensis were 69.5 and 93.9 ppm respectively.In the 24,48 and 72 h exposure of B.pfeifferi,the LC50 values were 72.4,69.9,64.7 ppm and the LC90 were 96.5,93.8,92.8 ppm,respectively.The phytochemical screening tests indicated presence of saponins.Conclusion:From the findings of this study,A.aspera has a molluscicidal potential.The result provides a useful foundation for further in-depth studies to ensure its wider applicability in different water bodies and evaluate its toxic effects on non-target species. | Belayhun Mandefro Seid Tiku Mereta Yinebeb Tariku Argaw Ambelu | 2017 | Infectious Diseases of Poverty2017，6，1： | 0 |
| 6 | Environmental determinants of distribution of freshwater snails and trematode infection in the Omo Gibe River Basin,southwest Ethiopia显示文摘Background:Determination of infection rates of snail populations is one of the basic tools for epidemiological studies of snail borne diseases.In this study,we opted to determine the trematode infection of freshwater snails in the Omo-Gibe River Basin,southwest Ethiopia.Methods:We collected snail samples from 130 observation sites in lakes,wetlands,rivers,reservoirs and irrigation canals surveyed during the dry season(March to May)in 2016.The snail samples were examined for trematode infections by cercarial shedding immediately after collection.Habitat conditions,water quality,human water contact practices and other human activities were assessed at each survey site.A redundancy analysis(RDA)was used to examine the relationship between cercarial infection and environmental variables.The statistical significance of eigenvalues and cercariae-environment correlations generated by the RDA were tested using Monte Carlo permutations at 499 permutations.Results:A total of 3107 snails belonging to five species were collected.The most abundant species was Biomphalario pfeifferi,representing 66%of the total collection.Overall,109(3.6%)of the snails were found infected with trematodes(cercariae).Biompholario pfeifferi was found to be the most highly infected,accounting 85%of all infected snails.A total of eight morphologically different types of cercariae were recorded,which included:Echinostoma cercariae,brevifurcate apharyngeate distome cercariae,amphistome cercariae,brevifurcate apharyngeate monostome cercariae,xiphidiocercariae,longifurcate pharyngeate distome cercariae,strigea cercariae and unidentified cercariae.Brevifurcate apharyngeate distome cercariae,and Echinostoma cercariae were the most abundant cercariae,accounting for 36 and 34%of all infection,respectively.The mean concentration of water conductivity and 5 days biological oxygen demand were higher in irrigation canals and lake sampling points.Human activities such as open field defecation,urination,livestock grazing,farming,and swimming were highly correlated with trematode infection.Conclusions:The abundance,occurrence and infection rates of snail species were largely influenced by water physicochemical quality,sanitation and water contact behaviour of the inhabitants.Human activities,such as open field defecation and urination,livestock grazing,farming,and swimming were important predictors of the abundance of cercariae.Therefore,awareness creation should be implemented for proper containment of excreta(urine and faeces)and reducing human and animal contacts with surface waters to reduce snail-borne disease transmission. | Seid Tiku Mereta Jemal Bedewi Delenasaw Yewhalaw Belayhun Mandefro Yihun Abdie Dechassa Tegegne Wondwosen Birke Worku Legesse Mulat Helmut Kloos | 2019 | Infectious Diseases of Poverty2019，8，6： | 0 |
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