Sinet, Ethiopian Journal of Science最新文献

{"title":"The linkage between geological setting and human health in Ethiopia: a preliminary geo-environmental-health model","authors":"S. Kebede","doi":"10.4314/SINET.V32I2.68857","DOIUrl":"https://doi.org/10.4314/SINET.V32I2.68857","url":null,"abstract":"Tropical environments are known for their prevalence of a number of geo-chemical diseases. This is related to the very nature of their geo-environments. Little research is conducted in geo-sciences in Ethiopia to investigate the linkage between geo-environments and associated health risks. Fluoride and related diseases are the most widely studied from geological perspectives. Ethiopia is characterized by complex but regionally homogeneous geo-environment. Climate is under the influence of monsoon from two oceans and continental sources. Locally orography modifies the redistribution of rainfall in the lee and wind ward directions. This leads to any combination of warm to cold and wet to dry climate. Prominent geologic features are rifting, volcanism and uplifting. Combination of geology, climate, and topography results in a complex pattern of geo-environment which in turn results in belts of availability or scarcity of certain geo-chemical elements. This work shows the presence of linkage between geo-environmental setting and prevalence of geo-chemical diseases such as goiter, elephantiasis, flourisis, and trace element related health problems. South-western Ethiopia, which is under the influence of Indian Ocean monsoon and underlain by volcanic rocks shows the highest incidence of Iodine Deficiency Disorder (IDD). Regions of Ethiopia under the influence of Atlantic Ocean monsoon or areas underlain by sediments and sedimentary rocks show the lowest IDD.  Elephantiasis prevalence is linked to laterite soils derived from chemical weathering of basalts, a typical process commonly taking place in humid plateau of south-western Ethiopia between altitudes of 1000 and 2000 masl.  Flouride related diseases are common features in area where water supply for domestic water use depend on aquifers in acid volcanic rocks, commonly in the rift setting. Regardless of the prevalence of geo-chemical diseases, Ethiopia is also endowed with natural geo-chemical materials of significant health benefits ( e.g. , Mineral waters and mud volcanoes). The work proposes a preliminary geo-environmental health model for Ethiopia.","PeriodicalId":245987,"journal":{"name":"Sinet, Ethiopian Journal of Science","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127828283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"VARIATIONS IN RAINFALL AND EXTREME EVENT INDICES IN THE WETTEST PART OF ETHIOPIA","authors":"Getenet Kebede, W. Bewket","doi":"10.4314/SINET.V32I2.68864","DOIUrl":"https://doi.org/10.4314/SINET.V32I2.68864","url":null,"abstract":"Changes in daily rainfall indices in the wettest (south-western) part of Ethiopia, commonly referred to as ‘year-round’ rainfall region were examined, by using records from nine stations over the period 1978–2007. Sixteen rainfall and dry spell related indices were defined and analyzed for trends; least squares regression was used to quantify trend and Kendall’s tau test was used to test statistical significance of trend. A complex picture of rainfall variability emerges from the analysis. Only one station (Gore) shows a statistically significant decline. The same station (Gore) shows significant decreasing trends in very wet day (R95p) and extremely wet day (R99p) amounts, whereas another station (Jimma) shows significant increasing trends in these parameters (total rainfall, very wet day and extremely wet day amounts); the other stations show no significant trends in these indices. Two of the stations (Asendabo and Sokoru) show statistically significant increasing trends in the maximum number of consecutive dry days. The results generally support previous studies in Ethiopia that there are no consistent patterns or trends in daily rainfall characteristics or seasonal rainfalls with the additional finding that choice of study stations strongly influences results of trend analysis. This suggests that regional scale conclusions may not be provided by analysis of few selected stations, given the high level of spatial variability at sub-regional scales in Ethiopia.","PeriodicalId":245987,"journal":{"name":"Sinet, Ethiopian Journal of Science","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127836181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Human-wildlife conflict in Zegie Peninsula (Ethiopia) with emphasis on grivet monkey (Cercopithecus aethiops aethiops)","authors":"Getachew Gebeyehu, A. Bekele","doi":"10.4314/SINET.V32I2.68859","DOIUrl":"https://doi.org/10.4314/SINET.V32I2.68859","url":null,"abstract":"Data on conflict between human and wildlife in Zegie Peninsula were collected during July, 2008-April, 2009. Face-to-face questionnaire, census of wild animals, direct estimation of crop damage by wild animals and faecal analysis of grivet monkeys were the components of the study. Data were analyzed using descriptive statistics; Chi-square test and one-way ANOVA. Crop loss in 2007/2008 harvest year was 26.78%. Damage estimation of ripened crops in the field by wild animals was equivalent to about 13,000 Ethiopian Birr per day in the study area (1150 ha). There was no significant difference in damage among crops (F = 0.147, df = 3, 16, P > 0.05) and damage in different habitats (F =1.41, df = 4, 15, P > 0.05). Among the faecal samples of grivet monkeys, 34.28% had the seeds of citrus fruits. Wild animals were killed in response to the damage they cause to crops or for consumption. Trees were cut down and sold to support livelihood. The estimated population of grivets in the study area was 1157, which is about one grivet monkey/ha. Grivet population was not significantly different between the wet and dry seasons (x 2 = 0.44, df =1, P > 0.05). But there was a significant difference in the population of grivets among habitats (F = 5.36, df = 4, 15, P 2 = 5.6, df =1, P < 0.05).  Grivet monkey, squirrel, porcupine and bushpig were the four major pest mammals in the area. Leopard, duiker and hares were minor pests.","PeriodicalId":245987,"journal":{"name":"Sinet, Ethiopian Journal of Science","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126672844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Milk production performance of Jersey cows at Wolaita Sodo State Dairy Farm, Southern Ethiopia","authors":"H. Lemma, K. Belihu, D. Sheferaw, G. Goshu","doi":"10.4314/SINET.V32I2.68868","DOIUrl":"https://doi.org/10.4314/SINET.V32I2.68868","url":null,"abstract":"This study was conducted in Wolaita Sodo State Dairy Farm to determine the milk yield, lactation length and productive herd life of Jersey cattle, and also the potential factors affecting these parameters. The Jersey cattle in the study farm were mainly kept on pastureland and with some supplementary feeds. The result of this study revealed that the overall mean values of milk yield, lactation length and lifetime milk yield were 1691.59 kg, 318.42 days and 5565.19 kg respectively. Milk yield, lactation and lactation length were significantly affected by year of calving and cattle source (p","PeriodicalId":245987,"journal":{"name":"Sinet, Ethiopian Journal of Science","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125729377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nutrient composition, volatile fatty acids production, digestible organic matter and anti-nutrtional factors of some agro-industrial by-products of Ethiopia","authors":"T. Negesse","doi":"10.4314/SINET.V32I2.68867","DOIUrl":"https://doi.org/10.4314/SINET.V32I2.68867","url":null,"abstract":"Nutrients, metabolizable energy (ME), anti-nutritional factors, digestible organic matter (DOM) and volatile fatty acids (VFA) production of 17 agro-industrial by-products from Ethiopia were determined. Highest amount of ash was found in fishmeal (FM) and of lignin in sisal waste (SW) and banana peels (BP). Cabbage leftover (CL), onion peels (OnP), papaya peels (PaP) and FM had high CP (137 to 490 g/kg DM) and NPN (51 to 141 g CP/kg DM); distillery by-product (DB) and brewery by-product (BB) had high CP (179 and 187 g/kg DM) and NDF (535 and 396 g/kg DM, respectively) but low NPN (21 and 9 g CP/kg DM). CL, OnP, PaP and FM had low NDF ( 576±9 g/kg DM) except avocado peels (AP) and BB. VFA concentrations were >19.1±1.8 mM except in CPa,FM and AP (< 12.1±2.9 mM). Coffee pulp (CPu), CL and MP had high total phenolics (123 to 151 g/kg DM) and tannin (42 to 86 g/kg DM). BP had largest amount of phytate. Hemolytic activity (saponin) was detected in FM, potato peels, SW, CPa and CL. The feeds can serve as sources of energy and protein.","PeriodicalId":245987,"journal":{"name":"Sinet, Ethiopian Journal of Science","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128585434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation and characterization of Bacillus thuringiensis from soils in contrasting agroecological zones of Ethiopia","authors":"Z. W. Tenssay, M. Ashenafi, A. Eiler, Stefan Bertilson","doi":"10.4314/SINET.V32I2.68863","DOIUrl":"https://doi.org/10.4314/SINET.V32I2.68863","url":null,"abstract":"Phenotypic and molecular methods were used to isolate and characterize B. thuringiensis from diverse agro-ecological zones of Ethiopia. Bioassays were used to test the insecticidal activity of B. thuringiensis strains against the major malaria vector, Anopheles arabiensis (Diptera). B. thuringiensis were isolated from 32% of the total 503 soil samples collected from the 16 agro-ecological zones. All sequenced isolates were 99%-100% identical to each other and to B. thuringiensis entries in Genbank. B. thuringiensis with similar 16S rRNA gene sequences from these different zones were characterized with regard to maximum growth rate and temperature optima for growth to test if there was local adaptation in these functional traits. The result showed a narrow temperature range around 30°C for maximal growth rate, and there were no significant differences between agro-ecological zones. Of 110 Bacillus thuringiensis isolates analyzed for the presence of crystal protein genes, 7 tested positive for cry 4, cry 11, and cyt toxin genes. Sequencing of these genes in positive strains demonstrated 99-100 % homology to known mosquitocidal cry and cyt genes in Bacillus thuringiensis subsp. israelensis. The present study shows that this biotechnologically important species is wide spread in Ethiopian soils and that it does not demonstrate local adaptation to temperature regimes, at least not for basic functions such as growth-temperature response. Our finding also pointed the potential for exploiting this species in vector control programs.","PeriodicalId":245987,"journal":{"name":"Sinet, Ethiopian Journal of Science","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130854790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oligotrophication trend of Lake Ziway, Ethiopia","authors":"G. Beneberu, S. Mengistou","doi":"10.4314/SINET.V32I2.68865","DOIUrl":"https://doi.org/10.4314/SINET.V32I2.68865","url":null,"abstract":"Some ecological changes have been noted in Lake Ziway since the 1980s, such as lowering of the lake level, introduction and dominance of the catfish Clarias gariepinus in the fishery (53%) and establishment of cladocerans such as Daphnia barbata and Ceriodaphnia cornuta . This prompted us to study the phytoplankton biomass to see whether these changes were cascaded through the trophic food chain of Lake Ziway. The dynamics of some chemical and biological parameters were studied in two littoral and one offshore sites in the lake from November 2003 to August 2004. Nutrients showed temporal as well as spatial variations. Nitrate increased in the offshore whereas soluble reactive phosphate (SRP) was high in littoral sites (20–380 µg/L), indicating anthropogenic impacts. Mean phytoplankton biomass was high at the offshore (43.85 mg Chl a m -3 ) and almost similar at the littoral sites (Mean values 33.73 and 33.68 mg Chl a m -3 ), but much lower than values reported earlier. Hourly rate of integral photosynthesis (∑a) ranged from 57.4–726 mg O 2 m -2 h -1 at the offshore and 95–300 mg O 2 m -2 h -1 at littoral sites, respectively. Biomass-specific rate of photosynthetic production at light saturation, (photosynthetic capacity, Φmax) ranged from 5.06–28.8 mg O 2 (mg Chl a ) -1 h -1 , slightly higher than values reported in the 1980s (9.6–22.5), due to depressed algal biomass. Although nutrients have increased, phytoplankton biomass (as Chl a ) has decreased over the last two decades, possibly due to heavy grazing by zooplankton and introduced fish. If this continues for some time, Lake Ziway will head towards oligotrophication, instead of eutrophication, as speculated by previous workers.","PeriodicalId":245987,"journal":{"name":"Sinet, Ethiopian Journal of Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131226816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Susceptibility of Sitophilus zeamais (Mostch.) (Coleoptera: Curculionidae) to Beauveria bassiana and Metarhizium anisopliae","authors":"A. Teshome, T. Tefera","doi":"10.4314/SINET.V32I1.68734","DOIUrl":"https://doi.org/10.4314/SINET.V32I1.68734","url":null,"abstract":"Evaluation of eleven Metarhizium anisopliae and six Beauveria bassiana isolates against the maize weevil Sitophilus zeamais was conducted under laboratory with the objectives of identifying the most virulent locally available fungal isolates, and determining the dose mortality response. The pathogenicity (virulence) of the entomopathogenic fungi was determined using LT50 and percent mortality at the conidial concentration of 1 x 108 ml-1. The most virulent isolates of M. anisopliae (PPRC-2, PPRC-14 and PPRC-51) and B. bassiana (PPRC-GG and PPRC-HH) caused 84.4% to 98.3% mortality to S. zeamais. These isolates had LT50 ranging from 3.8 to 4.3 days. The dose response study with the isolates PPRC-2, PPRC-14 and PPRC-51 at doses ranging from 1x 104 to 1x 108 conidia  ml-1  revealed susceptibility of the S. zeamais with mortality ranging from 25 to 95.5%. There was an increase in the resulting LT50 from 4.0 to 11.9 days with a decrease in conidial concentration from 1x 108 to 1x 104 conidia ml-1. PPRC-2 showed the lowest LC50 (1.46x 10 conidia ml-1) followed by PPRC-14 and PPRC-51 (3.5x 105 and 3.9x 105 conidia ml-1, respectively). In conclusion, the isolates PPRC-2, PPRC-14, PPRC-51, PPRC-GG and PPRC-HH, can be considered as a potential candidates in the development of mycoinsectisdes against S. zeamais.","PeriodicalId":245987,"journal":{"name":"Sinet, Ethiopian Journal of Science","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132028738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Species composition, relative abundance and habitat association of the bird fauna of the montane forest of Zegie Peninsula and nearby islands, Lake Tana, Ethiopia","authors":"Shimelis Aynalem, A. Bekele","doi":"10.4314/SINET.V32I1.68731","DOIUrl":"https://doi.org/10.4314/SINET.V32I1.68731","url":null,"abstract":"The present study was carried out in Zegie Peninsula and Kibran Gebriel and Entos Iyesus Islands of Lake Tana from August 2006 to March 2007. Sampling sites were stratified based on the vegetation type and area cover. Point count technique and chi-square test were employed to see the association of birds with the different vegetation strata. A total of 101 bird species were recorded, out of which 91 were residents (three endemics) and 10 were Palaearctic migrants. The Zegie Peninsula had high species diversity and evenness (0.96 and 0.86, respectively). The relative abundance of birds during the wet and dry seasons was variable. A total of 54 and 68 species were recorded during the wet and dry seasons in the Zegie Peninsula, respectively. The islands possessed 24 species each season. Habitat association of birds within the vegetation strata of Zegie Peninsula during the wet season was: highest at the shore (4.50), followed by gardens (4.00), bushes and shrubs (3.33) and trees (2.17). During the dry season, the highest mean number of birds occurred in the garden vegetation (4.86), followed by trees (3.23), fringe type of vegetation (3.22), and bush and shrub vegetation (2.60). During the wet season, the association of birds with the vegetation stratum was not statistically significant (p > 0.05, chi-square =13, df =7, n = 32). However, this was significant during the dry season (p < 0.05, chi-square = 66.238, df =9, n = 84). Conservation action to minimize the anthropogenic effect at Zegie should be the order of the day.","PeriodicalId":245987,"journal":{"name":"Sinet, Ethiopian Journal of Science","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121700575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Some helminths of the Ethiopian wolf (Canis simensis Rüpell 1840, Canidae) and its prey in the Bale Mountains National Park.","authors":"Habte Jebessa","doi":"10.4314/SINET.V32I1.67887","DOIUrl":"https://doi.org/10.4314/SINET.V32I1.67887","url":null,"abstract":"Eggs of Trichuris vulpis were found in all fecal samples of Canis simensis and one had unfertilized Ascaris lumbricoides egg. Adult specimens of Echinococcus granulosus were observed once in a fecal sample of Canis simensis . Examination of additional fecal samples failed to reveal the adult parasite. However, unidentified Taenia species eggs were found in all of the fecal samples. Examination of liver of some rodents revealed an encysted Ascaris larva in Arvicanthis blicki .","PeriodicalId":245987,"journal":{"name":"Sinet, Ethiopian Journal of Science","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125959878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}