Browsing by Author "Tesfaye Alemu"

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    Communication Strategies Utilized by Omo TTi Trainee-Teachers in Oral Production of English
    (Addis Ababa University, 2007-06) Tesfaye Alemu ; Tibebe Alemayehu
    This study was carried out to investigate trainee-teachers’ utilization of communication strategies in their oral production of English. Consequently, the study involved eight OMO TTI trainee-teachers. Four of them were from Gamo Department and the other four were from Amharic Department. In order to investigate variation, if any, in utilization of the strategies between female and male trainees, equal number of subjects, i.e. two from each sex, were selected. Thus, they were provided with five different tasks to illicit information. Three of the tasks were grade four lessons which the subjects were supposed to teach to grade four students. The other two tasks were “description of home village” and explaining about “glow worms” which the subjects were expected to talk to English native speakers. Having been provided with these tasks, the subjects were observed while they were presenting the tasks. The observation was aided by video-recording and tape-recording. In the end, the recorded data were transcribed and the types of communication strategies utilized by the subjects were analyzed. The results of the study revealed that almost all the subjects were effective in utilization of communication strategies when they were communicating with the expatriates. However, Amharic trainees were better than Gamo trainees in employing the strategies during the teaching activities. Among trainees of Gamo Department, the male trainees were better than the female trainees. On the other hand, female trainees of Amharic Department were as effective as the male counterparts in the same Department. Despite all these, all the trainees were found to be deficient in their language. Their English language was not to the level that enabled them to teach English. Utilization of both linguistic and nonlinguistic strategies during teaching practice appeared to help trainees of Amharic Department better than trainees of Gamo Department. On the contrary, all the trainees were reported to be effective in transmitting their message to the expatriates. This was because the expatriates were focusing on meaning (theme) rather than the trainees’ grammar. In general, it was concluded that though the trainees were effective n communicating meaning, their language was not to the mark that enabled them to be effective in teaching English. As a result, it was recommended that Teachers’ Training Institute as well as teacher trainers should be aware of the need to balance accuracy and fluency based teaching of English language. Moreover, syllabus designers as well as high school teachers ought to be conscious that English language teaching in high schools should be geared to balance the focus of accuracy and fluency based teaching
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    Isolation and Characterization of Dichlorodiphenyltrichloroethane (DDT) Degrading Fungi Isolated from Agro-Industrial Effluent and Farm Soils
    (Addis Ababa University, 2025-02) Girma Ebsa; Tesfaye Alemu
    Dichlorodiphenyltrichloroethane (DDT) is an environmentally hazardous synthetic compound that is resistant to usage. Despite being illegal in most countries, it is used as a pesticide to fight malaria in most malarial zone part of Ethiopia. The main objective of this study is to screen, characterize, and evaluate potential DDT-degrading fungi and their synergetic interaction effects for mycoremediation purposes. The composite of 150 soil and effluent samples was collected from Addis Ababa and East Shewa Zone, mainly Ziway and Koka. Fungal isolation and screening were performed using a serial dilution on potato dextrose agar growth media. MALDI-TOF MS technology was used for fungal identification. Fungal biomass production and sporulation capacity were examined and optimized using a Box-Behnken experimental design. The potential DDTtolerant fungi were studied based on growth factor optimization. Gas Chromatograph-Electron Capture Detector technology was used for the DDT degradation study. Fungal identification results revealed that the finally selected isolates, AS1 and T1, were Asppergillus niger and Trichoderma koningii, respectively. The optimization results confirmed that the co-inoculated isolates AS1T1 had a maximum biomass (1.01±0.16 g) and spore count (5.74±0.37 log spore/mL) and were selected as possible DDT-degrading fungi. The GC-ECD result analysis revealed that fungal-cocultured A. niger and T. koningii in DDT-amended liquid medium were able to degrade DDT into its metabolites Dichlorodiphenyldichloroethane (DDD) and Dichlorodiphenyldichloroethylene (DDE). The results also revealed that 99.5–99.99% of DDT and its metabolites degraded from initial concentrations of 1750, 3500, 5250, and 7000 ppm. The co-inoculated fungi A. niger and T. koningii are promising candidates for the removal of DDT and its metabolites from polluted environments.