Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic conditions.The A...Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic conditions.The African birch(Anogeissus leiocarpa(DC.)Guill.&Perr.)and pink jacaranda(Stereospermum kunthianum Cham.)trees are the dominant species in the agroforestry parkland system in the drylands of Tigray,Ethiopia.Smallholder farmers highly value these trees for their multifunctional uses including timber,firewood,charcoal,medicine,etc.These trees also could improve soil fertility.However,the amount of soil physical and chemical properties enhanced by the two species must be determined to maintain the sustainable conservation of the species in the parklands and to scale up to similar agroecological systems.Hence,we selected twelve isolated trees,six from each species that had similar dendrometric characteristics and were growing in similar environmental conditions.We divided the canopy cover of each tree into three radial distances:mid-canopy,canopy edge,and canopy gap(control).At each distance,we took soil samples from three different depths.We collected 216 soil samples(half disturbed and the other half undisturbed)from each canopy position and soil depth.Bulk density(BD),soil moisture content(SMC),soil organic carbon(SOC),total nitrogen(TN),available phosphorus(AP),available potassium(AK),p H,electrical conductivity(EC),and cation exchange capacity(CEC)were analysed.Results revealed that soil physical and chemical properties significantly improved except for soil texture and EC under both species,CEC under A.leiocarpus,and soil p H under S.kunthianum,all the studied soils were improved under both species canopy as compared with canopy gap.SMC,TN,AP,and AK under canopy of these trees were respectively 24.1%,11.1%,55.0%,and 9.3% higher than those soils under control.The two parkland agroforestry species significantly enhanced soil fertility near the canopy of topsoil through improving soil physical and chemical properties.These two species were recommended in the drylands with similar agro-ecological systems.展开更多
The study was conducted to determine the applicability of gravity separation method on the Ashashire gold ore deposit Benishangul gumuz region, western Ethiopia. The Ashashire composite was produced to provide suffici...The study was conducted to determine the applicability of gravity separation method on the Ashashire gold ore deposit Benishangul gumuz region, western Ethiopia. The Ashashire composite was produced to provide sufficient mass for this study and experiment, including sample preparation, mineralogical analysis of gold and associated elements, gravity concentration, and data interpretation and analysis. During the study, a grind optimization was conducted on the composites sample with varying grind size to evaluate the effect of grind size on gold recovery. The ore was moderately ground to the standard grind size of 80%, passing 106 µm, 75 µm, 53 µm and this nominal size was selected for the preliminary assessment for concentration optimization for this deposit. The gravity testing comprised three-stage concentration using Knelson concentrator. High recovery of gold from the gravity concentrates was achieved from the second gravity concentration. Based on the laboratory experimental result analysis, a grind size of P80 75 µm is selected as optimal size for the Ashashire gold deposit. Increasing the grind size from P80 of 75 µm to 106 µm decreases the recovery rate from 75% to 54%, or decreasing the grind size from P80 of 75 µm to 53 µm decreases the gold recovery rate to 37%. The native gold grain in the ores is mostly associated with quartz and fine gold is closely associated with pyrite. According to analysis of the fire assay, chemical, and mineralogical data, only gold and telluride is commercially valuable elements in the ores. Predominantly gold was occurred in the native form of Au-Te. The sample subjected to gravity separation assayed about 2.6 g/t Au.展开更多
Objective:To assess the food safety knowledge and practices in meat handling,and to determine microbial load and pathogenic organisms in meat at Mekelle city.Methods:A descriptive survey design was used to answer ques...Objective:To assess the food safety knowledge and practices in meat handling,and to determine microbial load and pathogenic organisms in meat at Mekelle city.Methods:A descriptive survey design was used to answer questions concerning the current status of food hygiene and sanitation practiced in the abattoir and butcher shops.Workers from the abattoir and butcher shops were interviewed through a structured questionnaire to assess their food safety knowledge.Bacterial load was assessed by serial dilution method and the major bacterial pathogens were isolated by using standard procedures.Results:15.1%of the abattoir workers had no health certificate and there was no hot water,sterilizer and cooling facility in the abattoir.11.3%of the butchers didn’t use protective clothes.There was a food safety knowledge gap within the abattoir and butcher shop workers.The mean values of bacterial load of abattoir meat,butcher shops and street meat sale was found to be 1.1×10~5,5.6×10~5and 4.3×10~6 cfu/g,respectively.The major bacterial pathogens isolated were Escherichia coli,Staphylococcus aureus and Bacillus cereus.Conclusions:The study revealed that there is a reasonable gap on food safely knowledge by abattoir and butcher shop workers.The microbial profile was also higher compared to standards set by World Health Organization.Due attention should be given by the government to improve the food safety knowledge and the quality standard of meat sold in the city.展开更多
Sixteen physicochemical parameters including four major and ten trace metals were analyzed for seven top soil and six top stream sediment samples collected around the vicinity of cement factory in Mekelle, Ethiopia. W...Sixteen physicochemical parameters including four major and ten trace metals were analyzed for seven top soil and six top stream sediment samples collected around the vicinity of cement factory in Mekelle, Ethiopia. Water and aqua regia extraction techniques were deployed to determine the water soluble and near total concentration of the metals in the samples. Water extraction results verified the magnitude of loading of the metals from anthropogenic sources. The mean values of the water soluble metals are found to exceed the reference values except for Ca and Zn in both lithogenic media indicating the severity of pollution. Spatial distribution of the metals suggested that cement factory dust and traffic emissions represent the most important pollutant sources for the investigated area.? The mean proportion of the major and trace metals in the water soluble phase of soil can be put on a descending order as: Mg (57.76%) > Fe > Ca > K > Na > Mn (3.77%) and Mo (53.17%) > Cu > Co > As > Ni > Zn > Pb > Cr (5.02%) respectively. The order of major metals is almost reverse in the case of the stream sediment with slight difference in the order of the trace metals. Factor analysis has revealed that the first factor represents the contribution of metals (Mn, Cr, As, Co, Zn, Na, K, Cu, Pb and Ni) from local anthropogenic activities, whereas the second factor represents the contribution of metals (Na, Fe, Cu, Pb, Ni, Ca, As, Co, Zn and Mo) from both lithogenic and anthropogenic origins. Third factor consists of Ca, Mo, Mg, and Fe from geogenic source of the local geology. It is spatially evident that the cement dust emission has an impact on the soil’s Cr, Co, Mo and Ni content which drastically decreases downstream. The spatial pattern of Cu, Pb, As, Zn and Co shows significant association with the cement dust and loadings from the traffic movement on the road.展开更多
The widespread emergence of antibiotic resistance among bacterial pathogens has become one of the most serious challenges in Ethiopia. This study determined the prevalence and drug resistance patterns of bacterial pat...The widespread emergence of antibiotic resistance among bacterial pathogens has become one of the most serious challenges in Ethiopia. This study determined the prevalence and drug resistance patterns of bacterial pathogens isolated from treated and untreated wastewater released from Ayder Referral Hospital in Northern Ethiopia. A cross sectional study design was conducted from September-December, 2015 in wastewater released from Ayder referral hospital. A total of 40 composite samples were aseptically collected, transported and processed for enumeration of indicator organisms, bacteriological identification and susceptibility testing following standard procedure. Data obtained were entered and analyzed using SPSS version 20. Mean heterotrophic plate count, total coliform count, fecal coliform count and E. coli count were found to be 1.6 × 106 CFU/mL, 2.2 × 106 CFU/100 mL, 2.0 × 105 CFU/100 mL and 1.1 × 104 CFU/100 mL from treated wastewater respectively. Among the total samples 134 bacterial isolates were detected and [84 (62.7%)] were from untreated wastewater and [50 (37.3%)] were from treated wastewater. The most frequently isolated bacteria from untreated wastewater samples was Klebsiella spp [14 (16.7%)] followed by S. aureus [13 (15.5%)] and P. aeruginosa [12 (14.3%)], similarly in treated wastewater samples Klebsiella spp [10 (20%)], P. aeruginosa [8 (16%)] and S. aureus [8 (16%)] were frequently detected. The overall multi-drug resistance (MDR) in this study was [79/134 (79.1%)]. MDR from untreated wastewater sample was [64/84 (76.2%)] while from treated wastewater sample was [42/50 (84%)] and shows significant difference with (COR: 1.64, 95% CI: 1.15 - 3.29, P: 0.001). It is concluded that treated hospital wastewater contains large numbers of antibiotic resistant bacteria. Therefore, there should be continuous monitoring and evaluation of the effluent quality of the ponds and chlorination of the final effluent should be developed.展开更多
Opuntia ficus-indica(L.)Miller is a CAM(crassulacean acid metabolism)plant with an extraordinary capacity to adapt to drought stress by its ability to fix atmospheric CO_(2) at nighttime,store a significant amount of ...Opuntia ficus-indica(L.)Miller is a CAM(crassulacean acid metabolism)plant with an extraordinary capacity to adapt to drought stress by its ability to fix atmospheric CO_(2) at nighttime,store a significant amount of water in cladodes,and reduce root growth.Plants that grow in moisture-stress conditions with thick and less fine root hairs have a strong symbiosis with arbuscular mycorrhizal fungi(AMF)to adapt to drought stress.Water stress can limit plant growth and biomass production,which can be rehabilitated by AMF association through improved physiological performance.The objective of this study was to investigate the effects of AMF inoculations and variable soil water levels on the biomass,photosynthesis,and water use efficiency of the spiny and spineless O.ficus-indica.The experiment was conducted in a greenhouse with a full factorial experiment using O.ficus-indica type(spiny or spineless),AMF(presence or absence),and four soil water available(SWA)treatments through seven replications.Water treatments applied were 0%–25%SWA(T1),25%–50%SWA(T2),50%–75%SWA(T3),and 75%–100%SWA(T4).Drought stress reduced biomass and cladode growth,while AMF colonization significantly increased the biomass production with significant changes in the physiological performance of O.ficus-indica.AMF presence significantly increased biomass of both O.ficus-indica plant types through improved growth,photosynthetic water use efficiency,and photosynthesis.The presence of spines on the surface of cladodes significantly reduced the rate of photosynthesis and photosynthetic water use efficiency.Net photosynthesis,photosynthetic water use efficiency,transpiration,and stomatal conductance rate significantly decreased with increased drought stress.Under drought stress,some planted mother cladodes with the absence of AMF have not established daughter cladodes,whereas AMF-inoculated mother cladodes fully established daughter cladodes.AMF root colonization significantly increased with the decrease of SWA.AMF caused an increase in biomass production,increased tolerance to drought stress,and improved photosynthesis and water use efficiency performance of O.ficus-indica.The potential of O.ficus-indica to adapt to drought stress is controlled by the morpho-physiological performance related to AMF association.展开更多
Colorectal cancer is the second leading cause of death from cancer among adults. The disease begins as a benign adenomatous polyp, which develops into an advanced adenoma with high-grade dysplasia and then progresses ...Colorectal cancer is the second leading cause of death from cancer among adults. The disease begins as a benign adenomatous polyp, which develops into an advanced adenoma with high-grade dysplasia and then progresses to an invasive cancer. Appropriate apoptotic signaling is fundamentally important to preserve a healthy balance between cell death and cell survival and in maintaining genome integrity. Evasion of apoptotic pathway has been established as a prominent hallmark of several cancers. During colorectal cancer development, the balance between the rates of cell growth and apoptosis that maintains intestinal epithelial cell homeostasis gets progressively disturbed. Evidences are increasingly available to support the hypothesis that failure of apoptosis may be an important factor in the evolution of colorectal cancer and its poor response to chemotherapy and radiation. The other reason for targeting apoptotic pathway in the treatment of cancer is based on the observation that this process is deregulated in cancer cells but not in normal cells. As a result, colorectal cancer therapies designed to stimulate apoptosis in target cells would play a critical role in controlling its development and progression. A better understanding of the apoptotic signaling pathways, and the mechanisms by which cancer cells evade apoptotic death might lead to effective therapeutic strategies to inhibit cancer cell proliferation with minimal toxicity and high responses to chemotherapy. In this review, we analyzed the current understanding and future promises of apoptotic pathways as a therapeutic target in colorectal cancer treatment.展开更多
Objective:To screen the antibacterial activity of nine ethnoveterinary plants traditionally used for the treatment of mastitis,wound and gastrointestinal complications.Methods:Hydroalcoholic exctracts of medicinal pla...Objective:To screen the antibacterial activity of nine ethnoveterinary plants traditionally used for the treatment of mastitis,wound and gastrointestinal complications.Methods:Hydroalcoholic exctracts of medicinal plants namely,Achyranthes aspera(A.aspera) L.(Family Asparagaceae),Ficus caria(F.caria)(Family Moraceae).Malvi parviflora(M.parviflora)(Family Malvaceae),Vernonia species(V.species) docal name Alakit.Family Asteraceae),Solatium hastifolium(S.hastifolium)(Family Solanaceae),Calpurinia aurea(C.aurea)(Ait) Benth(Family Fabaceae),Nicotiana tabacum(N.tabacum) L.(Family Solanaceae),Ziziphus spina-christi(Z.spina-christi)(Family Rhamnaceae).Croton macroslachys(C.macrostachys)(Family Fuphorhiaceae).were screened against clinical bacterial isolates of veterinary importance from October 2007 to April2009.The antibacterial activity was tested using disc diffusion at two concentrations(200 mg/mL and 100 mg/mL) and broth dilution methods using 70%methanol macerated leal extracts.Results:With the exception ol S.hastifolium all plant extracts exhibited antibacterial activity.Among the medicinal plants tested C.aurea.C.macrostachyus,A.aspera,N.tabacum and vcrnonia species(Alakit) showed the most promising antimicrobial properties.Conclusions:It can be concluded that many of the tested plants have antibacterial activity and supports the traditional usage of the plants for mastitis,wound and gastrointestinal complications treatment.Further studies into their toxicity and phytochemistry is advocated.展开更多
Arbuscular mycorrhiza fungi(AMF) are vital in the regeneration of vegetation in disturbed ecosystems due to their numerous ecological advantages and therefore are good indicators of soil and ecosystem health at large....Arbuscular mycorrhiza fungi(AMF) are vital in the regeneration of vegetation in disturbed ecosystems due to their numerous ecological advantages and therefore are good indicators of soil and ecosystem health at large. This study was aimed at determining how the seasonal, vegetation cover density, edaphic and anthropogenic factors affect AMF root colonization(RC) and spore density(SD)in Desa’a dry Afromontane forest. AMF RC and SD in the rhizosphere of five dominant woody species, Juniperus procera, Olea europaea, Maytenus arbutifolia, Carissa spinarum and Dodonaea angustifolia growing in Desa’a forest were studied during the rainy and the dry seasons in three permanent study vegetation cover density plots(dense, medium, and poor). Each plot(160 x40 m2) has two management practices(fenced and unfenced plots) of area. A 100 g sample of rhizosphere soil from moisturefree composite soil was used to determine spore density.Spore density ranged from 50 to 4467 spores/100 g soil,and all species were colonized by AMF within a range of 4–95%. Glomus was the dominant genus in the rhizosphere of all species. Vegetation cover density strongly affected SD and RC. The SD was significantly higher(p < 0.05) in the poor vegetation cover density than in the other two and lowest in the dense cover; root colonization showed the reverse trend. Management practices significantly(p <0.05) influenced AMF SD and RC, with the fenced plots being more favoured. Seasons significantly(p < 0.05) affected RC and SD. More RC and SD were observed in the wet period than the dry period. Correlating AMF SD and RC with soil physical and chemical properties showed no significant difference(p> 0.05) except for total nitrogen. Disturbance, vegetation cover density, season and total nitrogen are significant factors that control the dynamics and management interventions to maintain the forest health of dry Afromontane forests.展开更多
The phenotypic diversity of 274 Ethiopian durum wheat accessions was analyzed, taking their geographic origins into account. The aim was to assess the extent and patterns of agronomically important phenotypic variatio...The phenotypic diversity of 274 Ethiopian durum wheat accessions was analyzed, taking their geographic origins into account. The aim was to assess the extent and patterns of agronomically important phenotypic variation across districts of origin and altitude classes for major qualitative traits using diversity index and multivariate methods. Eight qualitative and three quantitative traits were scored for 2740 plants and analyzed for diversity. The Shannon–Weaver diversity(H′) index was used to estimate phenotypic diversity. The estimated H′ ranged from monomorphic for glume hairiness to highly polymorphic for other traits. The highest(0.86) H′ was obtained for seed degree of shriveling, possibly indicating the differential responses of the genotypes to water deficit during later growth stages. With respect to district of origin, the highest(0.72) and lowest(0.44) H′ values were obtained for the Bale and SNNP districts, respectively. With respect to altitude, the highest(0.76) and lowest(0.62) H′ values were recorded for altitudes 1600–2000and > 3000 m above sea levels, respectively. Principal components analysis explained substantial variation contributed by district of origin and altitude range. Genotypes were clustered into three groups by districts of origin and altitude class, with relatively strong bootstrap values of 57 and 62 for the former and latter, respectively. It could be concluded that Ethiopian durum wheat landraces are very diverse both within and among districts of origin and altitude classes. This wealth of genetic diversity should be exploited for wheat improvement of yield and for resistance to biotic and abiotic stresses, particularly terminal drought.展开更多
In the Ethiopian highlands, communal grazing lands are one of the major land uses, and are source of livelihood for the rural people. Free and uncontrolled grazing in the communal grazing lands is the dominant grazing...In the Ethiopian highlands, communal grazing lands are one of the major land uses, and are source of livelihood for the rural people. Free and uncontrolled grazing in the communal grazing lands is the dominant grazing system. The traditional uncontrolled and free grazing system has caused severe degradation of the grazing lands. As a result, communities have started to establish exclosures and support the restoration of degraded communal grazing lands. Studies have shown that exclosures are effective to restoring degraded communal grazing lands and improving ecosystem services. However, studies that investigate the changes in aboveground biomass following the establishment of exclosures and compare it with fuelwood demand of the beneficiaries in our study area is lacking. Therefore, our study aimed at:(1) quantifying yearly biomass accumulation in exclosures and compare it to fuelwood demand of households that manage the exclosures;(2) assessing household energy sources and their consumption levels. To monitor changes in biomass production with over time, replicated(n = 3) 5 and10 year-old exclosures were sampled. To investigate fuelwood sources and consumption patterns, household surveys, key informant interviews and focus group discussion were conducted. Our results demonstrated that total biomass production increased with exclosure age. In both exclosure, biomass production from Vachellia etbaica was significantly(p \ 0.05) greater than that from Euclea.racemosa. Average daily fuelwood consumption per person was(0.63 ± 0.2) kg day^(-1). This means that the total biomass(27.5 Mg year^(-1)) obtained from 114.6 ha of exclosures covers only 9.4% of yearly fuelwood demand of the residents who manage the sampled exclosures. Nearly all respondents(95%) confirmed that they travel more than10 km day^(-1) to gather fuelwood from surrounding degraded forest patches. We recommend plantings of fast growing native tree species within exclosures and around homesteads to provide a sustainable fuelwood supply and using improved stoves to address the problem of fuelwood shortage. District agricultural offices could provide seedlings of native plant species, while communities provide unpaid labour for planting and managing plantations.展开更多
Rootstocks have a significant influence on adaptation to biotic and abiotic stress conditions and quality of fruit.So,choice of rootstock for a specific growing region is an important decision for a grower to make whe...Rootstocks have a significant influence on adaptation to biotic and abiotic stress conditions and quality of fruit.So,choice of rootstock for a specific growing region is an important decision for a grower to make when establishing a commercial citrus orchard.This study was undertaken to assess effects of rootstock and location on quality of orange fruit.The study was conducted over two consecutive years(2017/18 and 2018/19).Scions from the Gunda Gundo orange grove were grafted on rough lemon and sour orange rootstocks and planted in Tigray and Afar,Ethiopia at four sites(Abala,Agulae,Adiha and Rama).The experiment was laid out in Randomized Complete Block Design(RCBD)with four replications.Data on different physico-chemical and bioactive compounds were collected and analyzed using R software(version 4).Compared to sour orange,rough lemon rootstock revealed higher fruit mass(151.96 g,195.38 g),fruit length(62.27 mm,68.88 mm)and fruit diameter(65.58 mm,71.3 mm),in 2017/18,2018/19,respectively.Among the four locations(Abala,Agulae,Adiha and Rama),higher juice percentage was found in Adiha(43.47%in 2017/18)and Abala(49.87%,in 2018/19).In 2017/18 higher total soluble solid(TSS,13.87%),TSS/acid ratio(19.18)and fruit rag(32.77%),were obtained at the Rama site.On the one hand,higher vitamin C(826.6 mg·kg^(-1))and total phenolic content(208 mg·kg^(-1 )GAE)were recorded at Agulae than Abala,Adiha and Rama sites from sour orange rootstock.High TSS,TSS/acid ratio and antioxidant were recorded from orange fruits at Rama site.This was expected to have resulted from hot climate conditions at the site.Besides,at a relatively cooler condition of the Agulae site,high phenolic,reduced ferric power and high vitamin C were recorded.Rough lemon rootstock improved fruit size,while rootstock did not affect the contents of TSS,TSS/acid ratio across the sites in both harvesting years.展开更多
Exclosure is a method of rehabilitating degraded lands by protecting them from the interference of animals and from human encroachment, and is used to regenerate native vegetation as a way to reduce soil erosion, incr...Exclosure is a method of rehabilitating degraded lands by protecting them from the interference of animals and from human encroachment, and is used to regenerate native vegetation as a way to reduce soil erosion, increase rain water infiltration and provide fodder and woody biomass in degraded grazing lands. Therefore, we studied woody plant structure, diversity and regeneration potentials in 5-and 10-year grazing exclosures in comparison with open grazed sites in a semi-arid environment. Data on species diversity, abundance, structure, basal area, frequency, density, and regeneration status were collected from 270 sample plots. Forty-one woody species representing 20 families were identified, with 18, 28 and 38 species found in open grazed areas, and in 5-and 10-year grazing exclosures, respectively. The 10-year grazing exclosures had a higher(P <0.05) species richness and plant densities compared to the 5-year grazing exclosures and the open grazed areas. The population structure and regeneration status of woody species in both grazing exclosures showed an inverted J-shape, indicating a healthy regeneration status, whereas hampered regeneration was observed in open grazed areas. The establishment of grazing exclosures had positive effects in restoring woody plant diversity and improving vegetation structure and regeneration potentials of degraded grazing lands.展开更多
Background:Anthropogenic disturbances are increasingly affecting the vitality of tropical dry forests.The future condition of this important biome will depend on its capability to resist and recover from these disturb...Background:Anthropogenic disturbances are increasingly affecting the vitality of tropical dry forests.The future condition of this important biome will depend on its capability to resist and recover from these disturbances.So 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 restoration.Methodology: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 2018.Resilience and resistance were measured using the anomalies(remainders)after time series decomposition into seasonality,trend and remainder components.Growth stability was calculated using the integral of the undecomposed NDVI data.These 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 R.Results: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 weaker.Precipitation of the wettest month,distance from settlements and slope were the most important factors associated with resilience,explaining 51%of the effect.Altitude,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 forest.Precipitation of the wettest month was the most important factor explaining 43.52%of the growth stability variation.Conclusion:A combination of climate,topographic factors and local human disturbance controlled the stability of the dry forest.Also tree diversity is an important stability component that should be considered in the management and restoration programs of such degraded forests.If local disturbances are alleviated the recovery time of dryland forests could be shortened,which is vital to maintain the ecosystem services these forests provide to local communities and global climate change.展开更多
The experiment was conducted on intercropping of lupine (Lupinus albus L.) with wheat (Triticum aestivum), barley (Hordeum vulgar) and finger millet (Eleusine coracana) in 2009 at Adet Agricultural research station, i...The experiment was conducted on intercropping of lupine (Lupinus albus L.) with wheat (Triticum aestivum), barley (Hordeum vulgar) and finger millet (Eleusine coracana) in 2009 at Adet Agricultural research station, in Western Gojam. The treatments were sole wheat at a seed rate of 175 kg/ha, sole barley at a seed rate of 125 kg/ha, sole finger millet at a seed rate of 30 kg/ha, sole lupine at a seed rate of 90 kg/ha, and an additive series of 25, 50 and 75% of the sole lupine seed rate combined with the full cereal seed rate to determine the effect of intercropping on competition (CR) among the different species, the land equivalent and area time equivalent ratios (LER and ATER);and the economic feasibility of each intercropping system(MAI) as compared with sole cropped. The experimental design was a completely randomized block with nine intercropping and four sole cropping systems in three replications. Lupine was planted in rows after establishment of main crops. JMP-5 (SAS, 2002) software’s was used to compute the analysis of variance. Partial LER of lupine was lower than LER of cereal, indicating an advantage for main crops and a disadvantage for the minor crop. Values of ATER showed 4.9%-31.3% and 11.1%-37.8% advantage in lupine-wheat and lupine-finger millet combinations, respectively, whilst lupine-barley combinations showed ATER of 54.5%-60.9% disadvantage. CR showed dominancy of wheat and barley over lupine while lupine was higher CR than finger millet. Positive MAI values were recorded in lupine-wheat and lupine-finger millet mixtures indicating that these intercropping systems were a definite yield advantage and the most profitable as compared to sole cropped. In conclusion, the lupine-finger millet mixture at the 50:100 seeding ratio and 75:100 seeding ratio;and lupine-wheat mixture at the 75:100 seeding ratio indicated a significant advantage from intercropping which was attributed to better MAI and land use efficiency (higher LER and ATER), lower CR and thereby enhanced sustainability of crop production in West Gojam, but the other socio-economic and cost of production aspects of intercropping should also be assessed especially under small scale farmers’ conditions.展开更多
The purpose of this experimental study was to evaluate and record the effects of T-2 toxicity alone and in association with IBV infection on haematobiochemical parameters. A total of 128 one-week-old chicks were divid...The purpose of this experimental study was to evaluate and record the effects of T-2 toxicity alone and in association with IBV infection on haematobiochemical parameters. A total of 128 one-week-old chicks were divided into four groups of 32 birds each and were treated respectively with T-2 toxin alone, IBV alone, T-2 toxin and co-infected with IBV, and no treatment (control) for a period of 6 weeks. Haematologically, the birds treated with T-2 toxin developed anaemia as indicated by significant decrease in haemoglobin levels, total erythrocyte counts and packed cell volume values;leucopenia, lymphocytopenia heterophilia and thrombocytopenia. The IBV infected birds exhibited lymphocytophilia and heteropoenia;the degrees of severity of leucopenia, lymphocytopenia heterophilia and thrombocytopenia were more pronounced in T-2+IBV groups. The serum biochemistry revealed hypoproteinemia and hypoalbuminemia in all the treated groups consistently. Besides, hypoglobulinemia and increased levels of alanine aminotransferase in T-2+IBV, and increased levels of alkaline phosphatase in toxin group alone were recorded. The changes in biochemical parameters were more in magnitude in the combination treatment group and their severity increased with duration of treatment. It was concluded that T-2 toxin made the birds more susceptible to IBV infection.展开更多
The beneficiation methods for Ethiopian Kenticha pegmatite–spodumene ores were assessed through mineralogical and quantitative analyses with X-ray diffraction(XRD) and energy-dispersive X-ray fluorescence(EDXRF)....The beneficiation methods for Ethiopian Kenticha pegmatite–spodumene ores were assessed through mineralogical and quantitative analyses with X-ray diffraction(XRD) and energy-dispersive X-ray fluorescence(EDXRF). The tantalite in the upper zone of the Kenticha pegmatite–spodumene deposit is 58.7wt% higher than that in the inner zone. XRD analysis revealed that the upper zone is dominated by manganocolumbite, whereas the inner zone is predominantly tantalite-Mn. Repeated cleaning and beneficiation of the upper-zone ore resulted in concentrate compositions of 57.34wt% of Ta_2O_5 and 5.41wt% of Nb_2O_5. Washing the tantalite concentrates using 1vol% KOH and 1 M H_2SO_4 led to the removal of thorium and uranium radioactive oxides from the concentrate. The findings of this study suggest that the beneficiation and alkaline washing of Kenticha pegmatite–spodumene ores produce a high-grade export-quality tantalite concentrate with negligible radioactive oxides.展开更多
A study was conducted in 2007/2008 at Absela locality, Banja Shikudad District of the Amhara National Regional State, Ethiopia to evaluate the effects of soil bunds stabilized with vetiver grass (IT. zizanioides) an...A study was conducted in 2007/2008 at Absela locality, Banja Shikudad District of the Amhara National Regional State, Ethiopia to evaluate the effects of soil bunds stabilized with vetiver grass (IT. zizanioides) and tree lucerne (C. palmensis) on soil physical and chemical properties, bund height, inter-terrace slope and barley (Hordeum vulgare L.) yield. Data were analyzed using one-way analysis of variance (ANOVA) and mean values for the treatments were separated using Duncan's Multiple Range Test. Results indicated that the non-conserved fields had significantly (p 〈 0.05) lower organic carbon and was found to contain 66% less OM from the average of the conserved treatment. 9-year old sole soil bund, the 9-year old soil bund stabilized with tree lucerne, the 9-year old soil bund stabilized with vetiver, and the 6-year old soil bund stabilized with tree lucerne had 71.20, 68.56, 52.30, and 36.12%, respectively higher percent OM than the control treatment. The trend was similar for total nitrogen. The non-conserved treatment had a higher bulk density when compared to the conserved fields. Fields with soil bunds stabilized with vetiver grass had the highest bund height and the lowest inter-terrace slope than fields treated with the rest of remaining conservation measures. Barley grain yields were significantly (P 〈 0.05) greater in both the soil accumulation and loss zones of the conserved fields than the non-conserved (control) treatment. Practicing soil conservation measures and curtailing causes of land degradation could improve the soil physical and chemical properties thereby increase land productivity of the conserved land.展开更多
The presence of pesticides in the environment is of great concern due to their persistent nature and chronic adverse effect on human health and the environment. Water bodies are subject to pollution by organochlorine ...The presence of pesticides in the environment is of great concern due to their persistent nature and chronic adverse effect on human health and the environment. Water bodies are subject to pollution by organochlorine pesticides, especially in developing countries, where water pollution is a key sustainability challenge. Hence, activated carbon is considered a universal adsorbent for the removal of organochlorine pollutants from water. Activated carbon from Acatia etbaica was prepared using traditional kilns with low investment costs. Pesticides such as aldrin, dieldrin and DDT were selected for adsorption because of their common usage in agricultural and malaria control activities and may occur in high concentrations in surface waters that are used as drinking water sources. The effect of the adsorbent dose and initial concentration were investigated. To describe the equilibrium isotherms the experimental data were analyzed by the Langmuir and Freundlich isotherm models. The Freundlich model gave the best correlation with the experimental data. Activated carbon prepared from Acacia etbaica was found to be an effective and low-cost alternative for the removal of organochlorine pesticides from aqueous solutions. The preparation method allows the use of this material by local communities for effective remediation of pollution by pesticides.展开更多
Women’s participation in each and every activity of a country is crucial. Especially to achieve the sustainable development goals involvement of girls and women in each sector of a nation contributes more and more. C...Women’s participation in each and every activity of a country is crucial. Especially to achieve the sustainable development goals involvement of girls and women in each sector of a nation contributes more and more. Considering women as family leaders;in many cultures in the household responsibility, taking care of their husband and children they are nation builders. However, participation, interaction and contribution of women outside of their house are not significant. Above all, in science and technology related matters their involvement is very weak. Therefore, this study deals with examining women’s participation in water resource management in Endertaworeda, specifically in Didba and Shibta sub-districts. The study result indicated that, the role of women in water management is high, especially in domestic level and the willingness to participate in external water issues was increased, but the decision making power never reached equality between men and women. The analysis shows that even though there are few women in the water committee of the local community and the water resource management sector, still their participation in decision making is insignificant. Even today, the society confirms the supremacy of men over women. As a result the policy at national levels as well as the regional level which emphasized on women’s participation in water resource management has become elusive its implementations. On the evidence of the study results, there are different barriers for women’s participation in management. The most frequently mentioned barriers are socio-cultural barriers, women’s low educational success and access in the country and low number of women in the office as managerial staff. Therefore, measures should be taken to enhance women’s participation in management position.展开更多
基金supported by the Sustainable Forest Management Project with the Local Communities in Tigray,northern Ethiopia,which was funded by the Norwegian Agency for Development Cooperation(NORAD)under the Norwegian Programme for Capacity Development in Higher EducationResearch for Development(NORHED)Programme(ETH 13/0018)+4 种基金the Ecological Organic Agriculture Project,Mekelle University,Ethiopiathe Institute of International Education-Scholars Rescue Fund(IIE-SRF)Norwegian University of Life Sciences(NMBU)Faculty of Environmental Sciences and Natural Resource Management(MINA)NORGLOBAL 2 Project in Ethiopia(303600)for supporting the research。
文摘Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic conditions.The African birch(Anogeissus leiocarpa(DC.)Guill.&Perr.)and pink jacaranda(Stereospermum kunthianum Cham.)trees are the dominant species in the agroforestry parkland system in the drylands of Tigray,Ethiopia.Smallholder farmers highly value these trees for their multifunctional uses including timber,firewood,charcoal,medicine,etc.These trees also could improve soil fertility.However,the amount of soil physical and chemical properties enhanced by the two species must be determined to maintain the sustainable conservation of the species in the parklands and to scale up to similar agroecological systems.Hence,we selected twelve isolated trees,six from each species that had similar dendrometric characteristics and were growing in similar environmental conditions.We divided the canopy cover of each tree into three radial distances:mid-canopy,canopy edge,and canopy gap(control).At each distance,we took soil samples from three different depths.We collected 216 soil samples(half disturbed and the other half undisturbed)from each canopy position and soil depth.Bulk density(BD),soil moisture content(SMC),soil organic carbon(SOC),total nitrogen(TN),available phosphorus(AP),available potassium(AK),p H,electrical conductivity(EC),and cation exchange capacity(CEC)were analysed.Results revealed that soil physical and chemical properties significantly improved except for soil texture and EC under both species,CEC under A.leiocarpus,and soil p H under S.kunthianum,all the studied soils were improved under both species canopy as compared with canopy gap.SMC,TN,AP,and AK under canopy of these trees were respectively 24.1%,11.1%,55.0%,and 9.3% higher than those soils under control.The two parkland agroforestry species significantly enhanced soil fertility near the canopy of topsoil through improving soil physical and chemical properties.These two species were recommended in the drylands with similar agro-ecological systems.
文摘The study was conducted to determine the applicability of gravity separation method on the Ashashire gold ore deposit Benishangul gumuz region, western Ethiopia. The Ashashire composite was produced to provide sufficient mass for this study and experiment, including sample preparation, mineralogical analysis of gold and associated elements, gravity concentration, and data interpretation and analysis. During the study, a grind optimization was conducted on the composites sample with varying grind size to evaluate the effect of grind size on gold recovery. The ore was moderately ground to the standard grind size of 80%, passing 106 µm, 75 µm, 53 µm and this nominal size was selected for the preliminary assessment for concentration optimization for this deposit. The gravity testing comprised three-stage concentration using Knelson concentrator. High recovery of gold from the gravity concentrates was achieved from the second gravity concentration. Based on the laboratory experimental result analysis, a grind size of P80 75 µm is selected as optimal size for the Ashashire gold deposit. Increasing the grind size from P80 of 75 µm to 106 µm decreases the recovery rate from 75% to 54%, or decreasing the grind size from P80 of 75 µm to 53 µm decreases the gold recovery rate to 37%. The native gold grain in the ores is mostly associated with quartz and fine gold is closely associated with pyrite. According to analysis of the fire assay, chemical, and mineralogical data, only gold and telluride is commercially valuable elements in the ores. Predominantly gold was occurred in the native form of Au-Te. The sample subjected to gravity separation assayed about 2.6 g/t Au.
基金Supported by the Tigray Regional National State,Science and Technology Agency(Grant No.TSTA/08/2010)
文摘Objective:To assess the food safety knowledge and practices in meat handling,and to determine microbial load and pathogenic organisms in meat at Mekelle city.Methods:A descriptive survey design was used to answer questions concerning the current status of food hygiene and sanitation practiced in the abattoir and butcher shops.Workers from the abattoir and butcher shops were interviewed through a structured questionnaire to assess their food safety knowledge.Bacterial load was assessed by serial dilution method and the major bacterial pathogens were isolated by using standard procedures.Results:15.1%of the abattoir workers had no health certificate and there was no hot water,sterilizer and cooling facility in the abattoir.11.3%of the butchers didn’t use protective clothes.There was a food safety knowledge gap within the abattoir and butcher shop workers.The mean values of bacterial load of abattoir meat,butcher shops and street meat sale was found to be 1.1×10~5,5.6×10~5and 4.3×10~6 cfu/g,respectively.The major bacterial pathogens isolated were Escherichia coli,Staphylococcus aureus and Bacillus cereus.Conclusions:The study revealed that there is a reasonable gap on food safely knowledge by abattoir and butcher shop workers.The microbial profile was also higher compared to standards set by World Health Organization.Due attention should be given by the government to improve the food safety knowledge and the quality standard of meat sold in the city.
文摘Sixteen physicochemical parameters including four major and ten trace metals were analyzed for seven top soil and six top stream sediment samples collected around the vicinity of cement factory in Mekelle, Ethiopia. Water and aqua regia extraction techniques were deployed to determine the water soluble and near total concentration of the metals in the samples. Water extraction results verified the magnitude of loading of the metals from anthropogenic sources. The mean values of the water soluble metals are found to exceed the reference values except for Ca and Zn in both lithogenic media indicating the severity of pollution. Spatial distribution of the metals suggested that cement factory dust and traffic emissions represent the most important pollutant sources for the investigated area.? The mean proportion of the major and trace metals in the water soluble phase of soil can be put on a descending order as: Mg (57.76%) > Fe > Ca > K > Na > Mn (3.77%) and Mo (53.17%) > Cu > Co > As > Ni > Zn > Pb > Cr (5.02%) respectively. The order of major metals is almost reverse in the case of the stream sediment with slight difference in the order of the trace metals. Factor analysis has revealed that the first factor represents the contribution of metals (Mn, Cr, As, Co, Zn, Na, K, Cu, Pb and Ni) from local anthropogenic activities, whereas the second factor represents the contribution of metals (Na, Fe, Cu, Pb, Ni, Ca, As, Co, Zn and Mo) from both lithogenic and anthropogenic origins. Third factor consists of Ca, Mo, Mg, and Fe from geogenic source of the local geology. It is spatially evident that the cement dust emission has an impact on the soil’s Cr, Co, Mo and Ni content which drastically decreases downstream. The spatial pattern of Cu, Pb, As, Zn and Co shows significant association with the cement dust and loadings from the traffic movement on the road.
文摘The widespread emergence of antibiotic resistance among bacterial pathogens has become one of the most serious challenges in Ethiopia. This study determined the prevalence and drug resistance patterns of bacterial pathogens isolated from treated and untreated wastewater released from Ayder Referral Hospital in Northern Ethiopia. A cross sectional study design was conducted from September-December, 2015 in wastewater released from Ayder referral hospital. A total of 40 composite samples were aseptically collected, transported and processed for enumeration of indicator organisms, bacteriological identification and susceptibility testing following standard procedure. Data obtained were entered and analyzed using SPSS version 20. Mean heterotrophic plate count, total coliform count, fecal coliform count and E. coli count were found to be 1.6 × 106 CFU/mL, 2.2 × 106 CFU/100 mL, 2.0 × 105 CFU/100 mL and 1.1 × 104 CFU/100 mL from treated wastewater respectively. Among the total samples 134 bacterial isolates were detected and [84 (62.7%)] were from untreated wastewater and [50 (37.3%)] were from treated wastewater. The most frequently isolated bacteria from untreated wastewater samples was Klebsiella spp [14 (16.7%)] followed by S. aureus [13 (15.5%)] and P. aeruginosa [12 (14.3%)], similarly in treated wastewater samples Klebsiella spp [10 (20%)], P. aeruginosa [8 (16%)] and S. aureus [8 (16%)] were frequently detected. The overall multi-drug resistance (MDR) in this study was [79/134 (79.1%)]. MDR from untreated wastewater sample was [64/84 (76.2%)] while from treated wastewater sample was [42/50 (84%)] and shows significant difference with (COR: 1.64, 95% CI: 1.15 - 3.29, P: 0.001). It is concluded that treated hospital wastewater contains large numbers of antibiotic resistant bacteria. Therefore, there should be continuous monitoring and evaluation of the effluent quality of the ponds and chlorination of the final effluent should be developed.
基金supported by the Ethiopian Ministry of Education.
文摘Opuntia ficus-indica(L.)Miller is a CAM(crassulacean acid metabolism)plant with an extraordinary capacity to adapt to drought stress by its ability to fix atmospheric CO_(2) at nighttime,store a significant amount of water in cladodes,and reduce root growth.Plants that grow in moisture-stress conditions with thick and less fine root hairs have a strong symbiosis with arbuscular mycorrhizal fungi(AMF)to adapt to drought stress.Water stress can limit plant growth and biomass production,which can be rehabilitated by AMF association through improved physiological performance.The objective of this study was to investigate the effects of AMF inoculations and variable soil water levels on the biomass,photosynthesis,and water use efficiency of the spiny and spineless O.ficus-indica.The experiment was conducted in a greenhouse with a full factorial experiment using O.ficus-indica type(spiny or spineless),AMF(presence or absence),and four soil water available(SWA)treatments through seven replications.Water treatments applied were 0%–25%SWA(T1),25%–50%SWA(T2),50%–75%SWA(T3),and 75%–100%SWA(T4).Drought stress reduced biomass and cladode growth,while AMF colonization significantly increased the biomass production with significant changes in the physiological performance of O.ficus-indica.AMF presence significantly increased biomass of both O.ficus-indica plant types through improved growth,photosynthetic water use efficiency,and photosynthesis.The presence of spines on the surface of cladodes significantly reduced the rate of photosynthesis and photosynthetic water use efficiency.Net photosynthesis,photosynthetic water use efficiency,transpiration,and stomatal conductance rate significantly decreased with increased drought stress.Under drought stress,some planted mother cladodes with the absence of AMF have not established daughter cladodes,whereas AMF-inoculated mother cladodes fully established daughter cladodes.AMF root colonization significantly increased with the decrease of SWA.AMF caused an increase in biomass production,increased tolerance to drought stress,and improved photosynthesis and water use efficiency performance of O.ficus-indica.The potential of O.ficus-indica to adapt to drought stress is controlled by the morpho-physiological performance related to AMF association.
文摘Colorectal cancer is the second leading cause of death from cancer among adults. The disease begins as a benign adenomatous polyp, which develops into an advanced adenoma with high-grade dysplasia and then progresses to an invasive cancer. Appropriate apoptotic signaling is fundamentally important to preserve a healthy balance between cell death and cell survival and in maintaining genome integrity. Evasion of apoptotic pathway has been established as a prominent hallmark of several cancers. During colorectal cancer development, the balance between the rates of cell growth and apoptosis that maintains intestinal epithelial cell homeostasis gets progressively disturbed. Evidences are increasingly available to support the hypothesis that failure of apoptosis may be an important factor in the evolution of colorectal cancer and its poor response to chemotherapy and radiation. The other reason for targeting apoptotic pathway in the treatment of cancer is based on the observation that this process is deregulated in cancer cells but not in normal cells. As a result, colorectal cancer therapies designed to stimulate apoptosis in target cells would play a critical role in controlling its development and progression. A better understanding of the apoptotic signaling pathways, and the mechanisms by which cancer cells evade apoptotic death might lead to effective therapeutic strategies to inhibit cancer cell proliferation with minimal toxicity and high responses to chemotherapy. In this review, we analyzed the current understanding and future promises of apoptotic pathways as a therapeutic target in colorectal cancer treatment.
基金Ethiopian Ministry of Science and Technology research and development grant FVS/11/2008
文摘Objective:To screen the antibacterial activity of nine ethnoveterinary plants traditionally used for the treatment of mastitis,wound and gastrointestinal complications.Methods:Hydroalcoholic exctracts of medicinal plants namely,Achyranthes aspera(A.aspera) L.(Family Asparagaceae),Ficus caria(F.caria)(Family Moraceae).Malvi parviflora(M.parviflora)(Family Malvaceae),Vernonia species(V.species) docal name Alakit.Family Asteraceae),Solatium hastifolium(S.hastifolium)(Family Solanaceae),Calpurinia aurea(C.aurea)(Ait) Benth(Family Fabaceae),Nicotiana tabacum(N.tabacum) L.(Family Solanaceae),Ziziphus spina-christi(Z.spina-christi)(Family Rhamnaceae).Croton macroslachys(C.macrostachys)(Family Fuphorhiaceae).were screened against clinical bacterial isolates of veterinary importance from October 2007 to April2009.The antibacterial activity was tested using disc diffusion at two concentrations(200 mg/mL and 100 mg/mL) and broth dilution methods using 70%methanol macerated leal extracts.Results:With the exception ol S.hastifolium all plant extracts exhibited antibacterial activity.Among the medicinal plants tested C.aurea.C.macrostachyus,A.aspera,N.tabacum and vcrnonia species(Alakit) showed the most promising antimicrobial properties.Conclusions:It can be concluded that many of the tested plants have antibacterial activity and supports the traditional usage of the plants for mastitis,wound and gastrointestinal complications treatment.Further studies into their toxicity and phytochemistry is advocated.
基金supported by The Steps Towards Sustainable Forest management with the Local Communities in Tigray,Northern Ethiopia(ETH 13/0018)
文摘Arbuscular mycorrhiza fungi(AMF) are vital in the regeneration of vegetation in disturbed ecosystems due to their numerous ecological advantages and therefore are good indicators of soil and ecosystem health at large. This study was aimed at determining how the seasonal, vegetation cover density, edaphic and anthropogenic factors affect AMF root colonization(RC) and spore density(SD)in Desa’a dry Afromontane forest. AMF RC and SD in the rhizosphere of five dominant woody species, Juniperus procera, Olea europaea, Maytenus arbutifolia, Carissa spinarum and Dodonaea angustifolia growing in Desa’a forest were studied during the rainy and the dry seasons in three permanent study vegetation cover density plots(dense, medium, and poor). Each plot(160 x40 m2) has two management practices(fenced and unfenced plots) of area. A 100 g sample of rhizosphere soil from moisturefree composite soil was used to determine spore density.Spore density ranged from 50 to 4467 spores/100 g soil,and all species were colonized by AMF within a range of 4–95%. Glomus was the dominant genus in the rhizosphere of all species. Vegetation cover density strongly affected SD and RC. The SD was significantly higher(p < 0.05) in the poor vegetation cover density than in the other two and lowest in the dense cover; root colonization showed the reverse trend. Management practices significantly(p <0.05) influenced AMF SD and RC, with the fenced plots being more favoured. Seasons significantly(p < 0.05) affected RC and SD. More RC and SD were observed in the wet period than the dry period. Correlating AMF SD and RC with soil physical and chemical properties showed no significant difference(p> 0.05) except for total nitrogen. Disturbance, vegetation cover density, season and total nitrogen are significant factors that control the dynamics and management interventions to maintain the forest health of dry Afromontane forests.
基金done through joint project between Mekelle University and Scuola Superiore Sant'Anna and the joint grant number is CDANR/ SSSA/42/2011The first author is further indebted to Scuola Superiore Sant'Anna, Italy for financial support given to the projectMekelle University for its support
文摘The phenotypic diversity of 274 Ethiopian durum wheat accessions was analyzed, taking their geographic origins into account. The aim was to assess the extent and patterns of agronomically important phenotypic variation across districts of origin and altitude classes for major qualitative traits using diversity index and multivariate methods. Eight qualitative and three quantitative traits were scored for 2740 plants and analyzed for diversity. The Shannon–Weaver diversity(H′) index was used to estimate phenotypic diversity. The estimated H′ ranged from monomorphic for glume hairiness to highly polymorphic for other traits. The highest(0.86) H′ was obtained for seed degree of shriveling, possibly indicating the differential responses of the genotypes to water deficit during later growth stages. With respect to district of origin, the highest(0.72) and lowest(0.44) H′ values were obtained for the Bale and SNNP districts, respectively. With respect to altitude, the highest(0.76) and lowest(0.62) H′ values were recorded for altitudes 1600–2000and > 3000 m above sea levels, respectively. Principal components analysis explained substantial variation contributed by district of origin and altitude range. Genotypes were clustered into three groups by districts of origin and altitude class, with relatively strong bootstrap values of 57 and 62 for the former and latter, respectively. It could be concluded that Ethiopian durum wheat landraces are very diverse both within and among districts of origin and altitude classes. This wealth of genetic diversity should be exploited for wheat improvement of yield and for resistance to biotic and abiotic stresses, particularly terminal drought.
基金financially supported by VLIRfunded project ‘Forest Rehabilitation through Natural Regeneration’DAAD
文摘In the Ethiopian highlands, communal grazing lands are one of the major land uses, and are source of livelihood for the rural people. Free and uncontrolled grazing in the communal grazing lands is the dominant grazing system. The traditional uncontrolled and free grazing system has caused severe degradation of the grazing lands. As a result, communities have started to establish exclosures and support the restoration of degraded communal grazing lands. Studies have shown that exclosures are effective to restoring degraded communal grazing lands and improving ecosystem services. However, studies that investigate the changes in aboveground biomass following the establishment of exclosures and compare it with fuelwood demand of the beneficiaries in our study area is lacking. Therefore, our study aimed at:(1) quantifying yearly biomass accumulation in exclosures and compare it to fuelwood demand of households that manage the exclosures;(2) assessing household energy sources and their consumption levels. To monitor changes in biomass production with over time, replicated(n = 3) 5 and10 year-old exclosures were sampled. To investigate fuelwood sources and consumption patterns, household surveys, key informant interviews and focus group discussion were conducted. Our results demonstrated that total biomass production increased with exclosure age. In both exclosure, biomass production from Vachellia etbaica was significantly(p \ 0.05) greater than that from Euclea.racemosa. Average daily fuelwood consumption per person was(0.63 ± 0.2) kg day^(-1). This means that the total biomass(27.5 Mg year^(-1)) obtained from 114.6 ha of exclosures covers only 9.4% of yearly fuelwood demand of the residents who manage the sampled exclosures. Nearly all respondents(95%) confirmed that they travel more than10 km day^(-1) to gather fuelwood from surrounding degraded forest patches. We recommend plantings of fast growing native tree species within exclosures and around homesteads to provide a sustainable fuelwood supply and using improved stoves to address the problem of fuelwood shortage. District agricultural offices could provide seedlings of native plant species, while communities provide unpaid labour for planting and managing plantations.
基金supported by the Open Society Foundation-Africa Climate Change Adaptation Initiative(OSF-ACCAI Grant No.OR2014-18350)。
文摘Rootstocks have a significant influence on adaptation to biotic and abiotic stress conditions and quality of fruit.So,choice of rootstock for a specific growing region is an important decision for a grower to make when establishing a commercial citrus orchard.This study was undertaken to assess effects of rootstock and location on quality of orange fruit.The study was conducted over two consecutive years(2017/18 and 2018/19).Scions from the Gunda Gundo orange grove were grafted on rough lemon and sour orange rootstocks and planted in Tigray and Afar,Ethiopia at four sites(Abala,Agulae,Adiha and Rama).The experiment was laid out in Randomized Complete Block Design(RCBD)with four replications.Data on different physico-chemical and bioactive compounds were collected and analyzed using R software(version 4).Compared to sour orange,rough lemon rootstock revealed higher fruit mass(151.96 g,195.38 g),fruit length(62.27 mm,68.88 mm)and fruit diameter(65.58 mm,71.3 mm),in 2017/18,2018/19,respectively.Among the four locations(Abala,Agulae,Adiha and Rama),higher juice percentage was found in Adiha(43.47%in 2017/18)and Abala(49.87%,in 2018/19).In 2017/18 higher total soluble solid(TSS,13.87%),TSS/acid ratio(19.18)and fruit rag(32.77%),were obtained at the Rama site.On the one hand,higher vitamin C(826.6 mg·kg^(-1))and total phenolic content(208 mg·kg^(-1 )GAE)were recorded at Agulae than Abala,Adiha and Rama sites from sour orange rootstock.High TSS,TSS/acid ratio and antioxidant were recorded from orange fruits at Rama site.This was expected to have resulted from hot climate conditions at the site.Besides,at a relatively cooler condition of the Agulae site,high phenolic,reduced ferric power and high vitamin C were recorded.Rough lemon rootstock improved fruit size,while rootstock did not affect the contents of TSS,TSS/acid ratio across the sites in both harvesting years.
基金the financial support of Tigray Agricultural Research Institute and Humera Agricultural Research Center,northern Ethiopia
文摘Exclosure is a method of rehabilitating degraded lands by protecting them from the interference of animals and from human encroachment, and is used to regenerate native vegetation as a way to reduce soil erosion, increase rain water infiltration and provide fodder and woody biomass in degraded grazing lands. Therefore, we studied woody plant structure, diversity and regeneration potentials in 5-and 10-year grazing exclosures in comparison with open grazed sites in a semi-arid environment. Data on species diversity, abundance, structure, basal area, frequency, density, and regeneration status were collected from 270 sample plots. Forty-one woody species representing 20 families were identified, with 18, 28 and 38 species found in open grazed areas, and in 5-and 10-year grazing exclosures, respectively. The 10-year grazing exclosures had a higher(P <0.05) species richness and plant densities compared to the 5-year grazing exclosures and the open grazed areas. The population structure and regeneration status of woody species in both grazing exclosures showed an inverted J-shape, indicating a healthy regeneration status, whereas hampered regeneration was observed in open grazed areas. The establishment of grazing exclosures had positive effects in restoring woody plant diversity and improving vegetation structure and regeneration potentials of degraded grazing lands.
基金PhD IRO grant from KU Leuven and We Forest Ethiopia supported the data collection.It is one of the chapters of a PhD research and there is no specific ID attached to the funds。
文摘Background:Anthropogenic disturbances are increasingly affecting the vitality of tropical dry forests.The future condition of this important biome will depend on its capability to resist and recover from these disturbances.So 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 restoration.Methodology: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 2018.Resilience and resistance were measured using the anomalies(remainders)after time series decomposition into seasonality,trend and remainder components.Growth stability was calculated using the integral of the undecomposed NDVI data.These 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 R.Results: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 weaker.Precipitation of the wettest month,distance from settlements and slope were the most important factors associated with resilience,explaining 51%of the effect.Altitude,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 forest.Precipitation of the wettest month was the most important factor explaining 43.52%of the growth stability variation.Conclusion:A combination of climate,topographic factors and local human disturbance controlled the stability of the dry forest.Also tree diversity is an important stability component that should be considered in the management and restoration programs of such degraded forests.If local disturbances are alleviated the recovery time of dryland forests could be shortened,which is vital to maintain the ecosystem services these forests provide to local communities and global climate change.
文摘The experiment was conducted on intercropping of lupine (Lupinus albus L.) with wheat (Triticum aestivum), barley (Hordeum vulgar) and finger millet (Eleusine coracana) in 2009 at Adet Agricultural research station, in Western Gojam. The treatments were sole wheat at a seed rate of 175 kg/ha, sole barley at a seed rate of 125 kg/ha, sole finger millet at a seed rate of 30 kg/ha, sole lupine at a seed rate of 90 kg/ha, and an additive series of 25, 50 and 75% of the sole lupine seed rate combined with the full cereal seed rate to determine the effect of intercropping on competition (CR) among the different species, the land equivalent and area time equivalent ratios (LER and ATER);and the economic feasibility of each intercropping system(MAI) as compared with sole cropped. The experimental design was a completely randomized block with nine intercropping and four sole cropping systems in three replications. Lupine was planted in rows after establishment of main crops. JMP-5 (SAS, 2002) software’s was used to compute the analysis of variance. Partial LER of lupine was lower than LER of cereal, indicating an advantage for main crops and a disadvantage for the minor crop. Values of ATER showed 4.9%-31.3% and 11.1%-37.8% advantage in lupine-wheat and lupine-finger millet combinations, respectively, whilst lupine-barley combinations showed ATER of 54.5%-60.9% disadvantage. CR showed dominancy of wheat and barley over lupine while lupine was higher CR than finger millet. Positive MAI values were recorded in lupine-wheat and lupine-finger millet mixtures indicating that these intercropping systems were a definite yield advantage and the most profitable as compared to sole cropped. In conclusion, the lupine-finger millet mixture at the 50:100 seeding ratio and 75:100 seeding ratio;and lupine-wheat mixture at the 75:100 seeding ratio indicated a significant advantage from intercropping which was attributed to better MAI and land use efficiency (higher LER and ATER), lower CR and thereby enhanced sustainability of crop production in West Gojam, but the other socio-economic and cost of production aspects of intercropping should also be assessed especially under small scale farmers’ conditions.
文摘The purpose of this experimental study was to evaluate and record the effects of T-2 toxicity alone and in association with IBV infection on haematobiochemical parameters. A total of 128 one-week-old chicks were divided into four groups of 32 birds each and were treated respectively with T-2 toxin alone, IBV alone, T-2 toxin and co-infected with IBV, and no treatment (control) for a period of 6 weeks. Haematologically, the birds treated with T-2 toxin developed anaemia as indicated by significant decrease in haemoglobin levels, total erythrocyte counts and packed cell volume values;leucopenia, lymphocytopenia heterophilia and thrombocytopenia. The IBV infected birds exhibited lymphocytophilia and heteropoenia;the degrees of severity of leucopenia, lymphocytopenia heterophilia and thrombocytopenia were more pronounced in T-2+IBV groups. The serum biochemistry revealed hypoproteinemia and hypoalbuminemia in all the treated groups consistently. Besides, hypoglobulinemia and increased levels of alanine aminotransferase in T-2+IBV, and increased levels of alkaline phosphatase in toxin group alone were recorded. The changes in biochemical parameters were more in magnitude in the combination treatment group and their severity increased with duration of treatment. It was concluded that T-2 toxin made the birds more susceptible to IBV infection.
文摘The beneficiation methods for Ethiopian Kenticha pegmatite–spodumene ores were assessed through mineralogical and quantitative analyses with X-ray diffraction(XRD) and energy-dispersive X-ray fluorescence(EDXRF). The tantalite in the upper zone of the Kenticha pegmatite–spodumene deposit is 58.7wt% higher than that in the inner zone. XRD analysis revealed that the upper zone is dominated by manganocolumbite, whereas the inner zone is predominantly tantalite-Mn. Repeated cleaning and beneficiation of the upper-zone ore resulted in concentrate compositions of 57.34wt% of Ta_2O_5 and 5.41wt% of Nb_2O_5. Washing the tantalite concentrates using 1vol% KOH and 1 M H_2SO_4 led to the removal of thorium and uranium radioactive oxides from the concentrate. The findings of this study suggest that the beneficiation and alkaline washing of Kenticha pegmatite–spodumene ores produce a high-grade export-quality tantalite concentrate with negligible radioactive oxides.
文摘A study was conducted in 2007/2008 at Absela locality, Banja Shikudad District of the Amhara National Regional State, Ethiopia to evaluate the effects of soil bunds stabilized with vetiver grass (IT. zizanioides) and tree lucerne (C. palmensis) on soil physical and chemical properties, bund height, inter-terrace slope and barley (Hordeum vulgare L.) yield. Data were analyzed using one-way analysis of variance (ANOVA) and mean values for the treatments were separated using Duncan's Multiple Range Test. Results indicated that the non-conserved fields had significantly (p 〈 0.05) lower organic carbon and was found to contain 66% less OM from the average of the conserved treatment. 9-year old sole soil bund, the 9-year old soil bund stabilized with tree lucerne, the 9-year old soil bund stabilized with vetiver, and the 6-year old soil bund stabilized with tree lucerne had 71.20, 68.56, 52.30, and 36.12%, respectively higher percent OM than the control treatment. The trend was similar for total nitrogen. The non-conserved treatment had a higher bulk density when compared to the conserved fields. Fields with soil bunds stabilized with vetiver grass had the highest bund height and the lowest inter-terrace slope than fields treated with the rest of remaining conservation measures. Barley grain yields were significantly (P 〈 0.05) greater in both the soil accumulation and loss zones of the conserved fields than the non-conserved (control) treatment. Practicing soil conservation measures and curtailing causes of land degradation could improve the soil physical and chemical properties thereby increase land productivity of the conserved land.
文摘The presence of pesticides in the environment is of great concern due to their persistent nature and chronic adverse effect on human health and the environment. Water bodies are subject to pollution by organochlorine pesticides, especially in developing countries, where water pollution is a key sustainability challenge. Hence, activated carbon is considered a universal adsorbent for the removal of organochlorine pollutants from water. Activated carbon from Acatia etbaica was prepared using traditional kilns with low investment costs. Pesticides such as aldrin, dieldrin and DDT were selected for adsorption because of their common usage in agricultural and malaria control activities and may occur in high concentrations in surface waters that are used as drinking water sources. The effect of the adsorbent dose and initial concentration were investigated. To describe the equilibrium isotherms the experimental data were analyzed by the Langmuir and Freundlich isotherm models. The Freundlich model gave the best correlation with the experimental data. Activated carbon prepared from Acacia etbaica was found to be an effective and low-cost alternative for the removal of organochlorine pesticides from aqueous solutions. The preparation method allows the use of this material by local communities for effective remediation of pollution by pesticides.
文摘Women’s participation in each and every activity of a country is crucial. Especially to achieve the sustainable development goals involvement of girls and women in each sector of a nation contributes more and more. Considering women as family leaders;in many cultures in the household responsibility, taking care of their husband and children they are nation builders. However, participation, interaction and contribution of women outside of their house are not significant. Above all, in science and technology related matters their involvement is very weak. Therefore, this study deals with examining women’s participation in water resource management in Endertaworeda, specifically in Didba and Shibta sub-districts. The study result indicated that, the role of women in water management is high, especially in domestic level and the willingness to participate in external water issues was increased, but the decision making power never reached equality between men and women. The analysis shows that even though there are few women in the water committee of the local community and the water resource management sector, still their participation in decision making is insignificant. Even today, the society confirms the supremacy of men over women. As a result the policy at national levels as well as the regional level which emphasized on women’s participation in water resource management has become elusive its implementations. On the evidence of the study results, there are different barriers for women’s participation in management. The most frequently mentioned barriers are socio-cultural barriers, women’s low educational success and access in the country and low number of women in the office as managerial staff. Therefore, measures should be taken to enhance women’s participation in management position.