Browsing by Author "Assefa, Daniel"
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Item Amharic Speech Training for the Deaf(Addis Ababa University, 2006-08) Assefa, Daniel; Midekso, Dida (PhD)It has been believed that all deaf persons can not make edible sound and can only communicate through Sign Language. However, Deaf people can make voices and communicate orally unless they are mute by nature. With speech training it is possible for the Deaf to learn how to speak and “listen”. Speech training can be given manually with a human trainer but it is a very tiresome task and its’ demands are more than the capability of trainers. The solution proposed for this problem is an automated speech training system which is already implemented for different languages. This thesis addresses a similar solution but for Amharic language. Due to the limitations of special equipment and software tools we can get we proposed modeling of a lip for the articulation of Amharic characters which is part of an automated speech training system. We used an Analysis-Synthesis approach to first analyze a real lip in speech making and applied the output of the analysis on our lip model to articulate different Amharic characters. The solution proposed is implemented in a prototype developed for selected Amharic characters and its efficiency is tested with some students of Mekanissa Deaf School. Keywords: Speech Training, Sign Language, Deaf Education, Lip modeling, Talking HeadItem Amharic Speech Training for the Deaf(Addis Ababa University, 2006-08) Assefa, Daniel; Midekso, Dida (PhD)It has been believed that all deaf persons can not make edible sound and can only communicate through Sign Language. However, Deaf people can make voices and communicate orally unless they are mute by nature. With speech training it is possible for the Deaf to learn how to speak and “listen”. Speech training can be given manually with a human trainer but it is a very tiresome task and its’ demands are more than the capability of trainers. The solution proposed for this problem is an automated speech training system which is already implemented for different languages. This thesis addresses a similar solution but for Amharic language. Due to the limitations of special equipment and software tools we can get we proposed modeling of a lip for the articulation of Amharic characters which is part of an automated speech training system. We used an Analysis-Synthesis approach to first analyze a real lip in speech making and applied the output of the analysis on our lip model to articulate different Amharic characters. The solution proposed is implemented in a prototype developed for selected Amharic characters and its efficiency is tested with some students of Mekanissa Deaf School. Keywords: Speech Training, Sign Language, Deaf Education, Lip modeling, Talking HeadItem Causes and Effects of Diminishing Water Volume in Lake Chelekleka, Bishoftu, Ethiopia and Strategy for Conservation(Addis Ababauniversity, 2015-06) Assefa, Daniel; worku, Hailu (PhD)This study aimed to examine Causes and Effects of Diminishing Water Volume in Lake Chelekleka, Bishoftu, Ethiopia and Strategy for Conservation. To meet the objective of the research, appropriate attention were taken to investigate the land use/cover changes, field observation, interviews with officials and horticulture farmers. Hence, the results of the study Shown, extent of the land use/cover change and its effects seen on Chelekleka Lake and its Swampy areas were very dramatic. That is, majority of the forest land use/covers during the (1973-2010) in Chelekleka Lake Water Shades and its surroundings were converted to crop land, settlement, degraded bare lands, and grass lands. This land use types covers much of the southern, western, Central and eastern parts of the Chelekleka Lake Watersheds and its surroundings. Besides, notably after 1986 land use/cover change was very tremendous and exhibited decline of forest lands, shrub lands, and swampy vegetation. Hence, during 1973- 1986 deforestation and soil degradation in the Chelekleka Lake Watersheds and its surroundings was very sever, which was ultimately affected the depth of the lake. In the same period majority of the forest and shrub lands in upper water course changes to grass lands, crop lands and bare-degraded lands, i.e., markedly, degraded bare land coverage was increased because of acute increase of agricultural lands. Moreover, the land use investigation data conclude the presence of a shift in land use types, for instance, agricultural lands were converted to population settlements areas and crop lands in turn expand to shrub and uncultivable land uses. Similarly irrigated vegetations also occupied the swampy areas of Chelekleka Lake. These land use changes caused massive reduction of surface water coverage and changes its shapes from deep dark blue and compacted shapes to slant shallow and light blue color shapes. Generally study concludes, all the Chelekleka lake especially, The inner and border areas of the lake Chelekleka was dramatically changed into irrigated vegetation and grass lands and hence the dying of the lake was already starting from upper and expands to its central areas. In addition to the challenges of land use change factors like high interest of Horticulture expansion, poorly planned infrastructure developments, lack of awareness and poor attention from governments, and climate change/variability exacerbate the dying of the lake. On the basis of the study findings of the research the following recommendations forwarded undertaking appropriate resource conservation and management approaches, both the lake and its buffer zone should be demarcated and administered by concerned bodies, the silt and sedimentation filled the base of the lake should be removed, appropriately designed ditch and/or bridges to transfer the streams from upper course to the lake should be implemented. Key words: Lake Chelekleka Land use land cover changeItem Identification and Functional Aspects of Protein Kinase Activity in Leishmania Aethiopica(Addis Ababa University, 1993-08) Assefa, Daniel; Skoglund, Goran (PhD); Worku, Yesehak (PhD)Protein kinase activity was demonstrated on intact Leishmania aethiopica promastigotes but not on heat generated "amastigotes". Similar work conducted on lysed cells revealed enzyme activity in soluble and particulate fraction of flagellated parasites. Enzyme on intact cell plasma membrane preferred Histone V-S over protamine as in vitro substrate whereas enzyme from soluble or particulate fraction of lysed cells displayed the reverse in vitro preference. On the other hand enzymes from both intact and lysed cells were inhibited by Staurosporine and Formycin ATP. Incubation of intact stationary phase parasites with t 2pJ ATP led to phosphorylation of eight protein bands. Similar experiment conducted using lysed cells revealed twenty bands. Incubation of the cells with [32pJ with the assumption of generating intracellular t2 P ] ATP also led to a patte111 of phosphorylation similar to that of lysed cells. It follows from the above that Leishmania aethiopica promastigotes possess both extra and intracellular endogenous substrates of protein kinases. Measurement of soluble kinase activity revealed increased activity as cells went from log to stationary phase where intact cell activity remained constant. Exposure to elevated temperature (37') induced transformation of the promastigotes to aff/agellated organism "amastigotes". This transformation resulted in a potent down regulation of both the soluble 'and the ecto kinase activities. In the promastigotes, Staurosporine caused morphological alterations. On the other hand Formycin ATP had a profound inhibitDlY effect on thymidine incorporation and cellular proliferation. These effects of Formycin ATP do not seem to be wholly accounted by its protein kinase inhibitory activity. A classical protein kinase C like activity could not be detected in the promastigotes. However, evidence for the probable presence of a phorbol ester insensitive, calcium and phospholipid independent protein kinase C is presented. All the same these observations do not rule out the presence of more than one subclass of protein kinases. This work suggests that major protein kinase activities may be involved in the regulation of proliferation, development and adaptation to "hostile" environment of Leishmania aethiopica promastigotes. It also argues that the continued study of key events in the biology of this organism is cTilcial in the development of better therapeuticstrategies.Item The Impacts of Women's Education on Elements of Reproductive Health and Governance(A.A.U, 2000-05) Assefa, Daniel; Yoseph, GetachewThe driving argument for conducting this study has come out of the belief that there are multifaceted benefits to investments in education other than the conventional private returns calculation earning differentials. among a wide range of variables that education can presumably exert effects upon, two elements of reproductive health and one element of governance were considered in this study. More specifically this study has committed itself to the investigation of the impacts of education on fertility, contraceptive use and political participation of women. by making use of a primary data from a survey on 1002 women of reproductive age living in urban sides of Addis Ababa and debre berhan estimations were made. the results show that generally education reduced fertility, raised contraception and positively contributed to the political participation of women. It was also proved that as opposed to the conventional wisdom that primary education is enough to exert such influences on t fettility and contraception, the findings showed at least a completion of grade eight schooling was required. /I was also found out that it was women's education and not husband's education that resulted in significant effects on all the three variables. Lastly, most of education's impact especially on fertility came about through the delaying of age at marriage.