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Search Results: 1 - 10 of 50549 matches for " Y Mekonnen "
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The prevalence of suicidal ideation and attempts among individuals attending an adult psychiatry out-patient clinic in Gondar, Ethiopia
D Mekonnen, Y Kebede
African Health Sciences , 2011,
Abstract: Background:Suicide is a common problem worldwide and the magnitude is high especially in countries where mental illnesses are prevalent and psychiatric services are poor. Objective: To determine the prevalence of suicidal ideation and attempts among patients who attended the Psychiatry clinic of Gondar University Hospital. Methods: A cross sectional study was conducted from March-December 2006 involving a total of 474 patients. Data was collected using a pre tested structured questionnaire containing basic socio-demographic variables, psychiatric diagnosis, suicidal ideation, suicidal attempt, the methods of suicide attempt and ways of survival from the attempted suicide. It was administered by psychiatry nurses working in the clinic. The data was analyzed anonymously using SPSS software. Results: The commonest mental illness was Major Depressive Disorder (51.3%) followed by Psychosis (38%). Ninety one (19.2 %) patients attempted suicide at least once after the onset of the current mental illness and 307(64.8%) have suicidal ideation. The common method of suicidal attempt was hanging (45.1%) and 69.2% were at home. An association was found between suicidal ideation and attempt (OR=33.7; CI=8.2-138.8, p-value <0.01). Conclusion: Suicidal ideation was common in psychiatric patients. It was also associated with suicidal attempt.
Anti-diarrheal activity of leaf extract of Juniperus procera and its effect on intestinal motility in albino mice
G Tafesse, Y Mekonnen
Journal of Medical and Biomedical Sciences , 2012,
Abstract: This study was designed to evaluate the anti-diarrheal property of Juniperus procera using albino mice. An aqueous extract of J. procera leaves was administered to albino mice at 150, 300, and 450 mg kg-1 (p.o). Wet feces, intestinal accumulation (enteropooling) and intestinal motility were rec-orded. The aqueous extract of J. procera significantly (p < 0.0001) decreased the mean number of wet faeces produced by the albino mice in a dose dependent manner as well as decreasing the dis-tance travelled by the charcoal meal (p < 0.0001) from 28.5 ± 1.1 cm when treated with 150 mg kg-1 to 11.8 ± 0.5 cm when treated with 450 mg kg-1 through 20.0 ± 1.0 cm when treated with 300 mg kg-1. Results obtained for the extract especially the 450 mg kg-1 dose was almost equivalent to diphe-noxylate and atropine sulphate (the reference drugs used). In conclusion, aqueous extract of J. procera demonstrated anti-diarrheal activity and could be an inexpensive and readily available anti-diarrheal remedy.
Problems Challenging the Academic Performance of Physics Students in Higher Governmental Institutions in the Case of Arbaminch, Wolayita Sodo, Hawassa and Dilla Universities  [PDF]
Sintayehu Mekonnen
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.65037
Abstract:

This study was conducted to examine problems that challenged academic performance of physics students in higher governmental institutions in the case of Arbaminch, Wolayita Sodo, Hawassa and Dilla Universities. Questionnaires, interviews and video recordings were used to collect relevant data for the study. Data from questionnaires was compiled and analyzed using a computerized data analysis package known as Statistical Package for Social Science SPSS 17.0. The Pearson chi-square test was used to compute to test association between dependent variable and independent variables and T-test was used to find out how academic performance varied with interest to subject matter. On the other hand, ANOVA test was used to test variation of the academic performance in study sites. Besides, percentages were used for comparison of data analysis. The findings reveal the existence of a significant influence of teachers both in fostering positive or negative attitude to subject (physics) and for their poor academic performance in lower class as well as in higher institutions. On the basis of the findings, the least percentage of students (16%) indicated that their current department was the best choice for them during application for admission. Whereas the highest percentage (84%) of sample class students was enrolled in department of physics without their interest and the academic performance (ESELS result), the highest percentage (70) of students who were admitted to department of physics was below 50%. The p values 0.01 and 0.00, respectively for students who are enrolled in department of physics with best choice and without their interest, are less than alpha level of significance (0.05), which reveals that, there is statistical significance academic performance deference between students in both cases. However, the difference is more significant for those students who are enrolled without their interest. By analysis of Pearson chi-square test summary in respective study sites, the p values 0.01, 0.007, 0.021 and 0.022 respectively are less than the alpha (α) level of significance of 0.05, which reveals that there is strong association between those variables. In the other corner of the ANOVA test analysis indicates that p value 0.01 is less than alpha level of significance 0.05. This reveals variation of academic performance of students between four higher governmental institutions where the study is made.

The blue water footprint of electricity from hydropower
M. M. Mekonnen ,A. Y. Hoekstra
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2012,
Abstract: Hydropower accounts for about 16% of the world's electricity supply. It has been debated whether hydroelectric generation is merely an in-stream water user or whether it also consumes water. In this paper we provide scientific support for the argument that hydroelectric generation is in most cases a significant water consumer. The study assesses the blue water footprint of hydroelectricity – the water evaporated from manmade reservoirs to produce electric energy – for 35 selected sites. The aggregated blue water footprint of the selected hydropower plants is 90 Gm3 yr 1, which is equivalent to 10% of the blue water footprint of global crop production in the year 2000. The total blue water footprint of hydroelectric generation in the world must be considerably larger if one considers the fact that this study covers only 8% of the global installed hydroelectric capacity. Hydroelectric generation is thus a significant water consumer. The average water footprint of the selected hydropower plants is 68 m3 GJ 1. Great differences in water footprint among hydropower plants exist, due to differences in climate in the places where the plants are situated, but more importantly as a result of large differences in the area flooded per unit of installed hydroelectric capacity. We recommend that water footprint assessment is added as a component in evaluations of newly proposed hydropower plants as well as in the evaluation of existing hydroelectric dams, so that the consequences of the water footprint of hydroelectric generation on downstream environmental flows and other water users can be evaluated.
In Vivo anti-malarial activities of Clerodendrum myricoides, Dodonea angustifolia and Aloe debrana against Plasmodium berghei
T Deressa, Y Mekonnen, A Animut
Ethiopian Journal of Health Development , 2010,
Abstract: Background: Malaria caused by the parasite Plasmodium falciparum is an acute disease which kills an estimated 863,000 people per year according to the WHO report of 2009. The fight against malaria is faced with the occurrence of widespread resistance of P. falciparum. The search for plant-derived antimalarial drugs has great importance in this regard. Thus this study evaluates the toxicity and antimalarial activity of extracts of Clerodendrum myricoides, Dodonia angustifolia and Aloe debrana. Method: Acute and sub acute toxicity studies of the extracts were carried out by giving up to 3000mg/kg to noninfected mice. Weight loss, change in general behavior and mortality were used as indicators of toxicity. Doses of 200, 400 & 600mg/kg/day of each extract of C.myricoides, D. dodonia and A.debrana were given orally to Plasmodium berghei infected mice following the four-day suppressive test procedure. Results: None of the extracts caused symptoms of toxicity at the given doses. Each extract showed variable level of parasitaemia suppression in dose related manner. Methanol extract of C. myricoides leaves exerted 82.50% suppression at the dose of 600mg/kg. The methanol extract of the root of D. angustifolia showed the highest (84.52%) suppression of parasitaemia at the dose of 600mg/kg. Furthermore, methanol extract of A. debrana induced 73.95% suppression, whereas its water extract exerted 54.36% suppression of parasitaemia. Conclusion: Crude extracts of C. myricoides, D. angustifolia and A.debrana caused strong activities against P. berghei indicating that they contain some chemical constituents that possibly lead to antimalarial drug development. [Ethiop. J. Health Dev. 2010; 24(1):25-29]
Adult Mosquito Populations and Their Health Impact around and far from Dams in Tigray Region, Ethiopia
D Tadesse, Y Mekonnen, A Tsehaye
Momona Ethiopian Journal of Science , 2012,
Abstract: Malaria control program in Ethiopia has a history of more than 40 years, but still now, malaria is a major cause of morbidity and mortality in Ethiopia. The objective of this study is to assess the impact of dam construction in the distribution of mosquito in intervention (dam nearby villages) and controlled (villages far from dam). Indoor adult mosquitoes were collected using 144 CDC light traps from 12 villages (6 from the intervention and 6 from the control villages) Community- based malaria parasitology was also done. Sampling was done in November 2005, December 2005, May 2006 and September 2006). A total of 1713 adult indoor mosquitoes were collected, of these, 1182 (69%) were Anopheles and 531 (31%) Culex. The prevalence of Anopheles was 45.77% in the intervention villages and 23.23% in the controlled villages (F p = 0.012). The prevalence of Anopheles increased twice in the intervention compared to the controlled villages. A total of 1436 children, 888 from intervention and 548 from control villages were examined for malaria parasitology. Only 57 children were found infected by Plasmodium species. Malaria prevalence rate was 3.97% (4.17% and 3.65% in intervention and control village, respectively)(x2 = 0.11, p= 0.7399). Among the 57 malaria positive cases in 32 (56.14%) we found P. vivax and in the 25 (43.86%) P. falciparum. We can tentatively conclude that the dams situated at 2000m and above do resulted two fold adult indoor mosquito, but do not seem to have resulted in a markedly higher incidence of malaria in the region. The study concludes that concerned authorities should take appropriate measures to improve health-care facilities for local communities when planning new irrigation schemes wherever they occur.
A global and high-resolution assessment of the green, blue and grey water footprint of wheat
M. M. Mekonnen ,A. Y. Hoekstra
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2010,
Abstract: The aim of this study is to estimate the green, blue and grey water footprint of wheat in a spatially-explicit way, both from a production and consumption perspective. The assessment is global and improves upon earlier research by taking a high-resolution approach, estimating the water footprint of the crop at a 5 by 5 arc minute grid. We have used a grid-based dynamic water balance model to calculate crop water use over time, with a time step of one day. The model takes into account the daily soil water balance and climatic conditions for each grid cell. In addition, the water pollution associated with the use of nitrogen fertilizer in wheat production is estimated for each grid cell. We have used the water footprint and virtual water flow assessment framework as in the guideline of the Water Footprint Network. The global wheat production in the period 1996–2005 required about 108 billion cubic meters of water per year. The major portion of this water (70%) comes from green water, about 19% comes from blue water, and the remaining 11% is grey water. The global average water footprint of wheat per ton of crop was 1830 m3/ton. About 18% of the water footprint related to the production of wheat is meant not for domestic consumption but for export. About 55% of the virtual water export comes from the USA, Canada and Australia alone. For the period 1996–2005, the global average water saving from international trade in wheat products was 65 Gm3/yr. A relatively large total blue water footprint as a result of wheat production is observed in the Ganges and Indus river basins, which are known for their water stress problems. The two basins alone account for about 47% of the blue water footprint related to global wheat production. About 93% of the water footprint of wheat consumption in Japan lies in other countries, particularly the USA, Australia and Canada. In Italy, with an average wheat consumption of 150 kg/yr per person, more than two times the word average, about 44% of the total water footprint related to this wheat consumption lies outside Italy. The major part of this external water footprint of Italy lies in France and the USA.
The green, blue and grey water footprint of crops and derived crop products
M. M. Mekonnen ,A. Y. Hoekstra
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2011,
Abstract: This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996–2005. The assessment improves upon earlier research by taking a high-resolution approach, estimating the water footprint of 126 crops at a 5 by 5 arc minute grid. We have used a grid-based dynamic water balance model to calculate crop water use over time, with a time step of one day. The model takes into account the daily soil water balance and climatic conditions for each grid cell. In addition, the water pollution associated with the use of nitrogen fertilizer in crop production is estimated for each grid cell. The crop evapotranspiration of additional 20 minor crops is calculated with the CROPWAT model. In addition, we have calculated the water footprint of more than two hundred derived crop products, including various flours, beverages, fibres and biofuels. We have used the water footprint assessment framework as in the guideline of the Water Footprint Network. Considering the water footprints of primary crops, we see that the global average water footprint per ton of crop increases from sugar crops (roughly 200 m3 ton 1), vegetables (300 m3 ton 1), roots and tubers (400 m3 ton 1), fruits (1000 m3 ton 1), cereals (1600 m3 ton 1), oil crops (2400 m3 ton 1) to pulses (4000 m3 ton 1). The water footprint varies, however, across different crops per crop category and per production region as well. Besides, if one considers the water footprint per kcal, the picture changes as well. When considered per ton of product, commodities with relatively large water footprints are: coffee, tea, cocoa, tobacco, spices, nuts, rubber and fibres. The analysis of water footprints of different biofuels shows that bio-ethanol has a lower water footprint (in m3 GJ 1) than biodiesel, which supports earlier analyses. The crop used matters significantly as well: the global average water footprint of bio-ethanol based on sugar beet amounts to 51 m3 GJ 1, while this is 121 m3 GJ 1 for maize. The global water footprint related to crop production in the period 1996–2005 was 7404 billion cubic meters per year (78 % green, 12 % blue, 10 % grey). A large total water footprint was calculated for wheat (1087 Gm3 yr 1), rice (992 Gm3 yr 1) and maize (770 Gm3 yr 1). Wheat and rice have the largest blue water footprints, together accounting for 45 % of the global blue water footprint. At country level, the total water footprint was largest for India (1047 Gm3 yr 1), China (967 Gm3 yr 1) and the USA (826 Gm3 yr 1). A relatively large total blue water footprint as a result of crop production is observed in the Indus river basin (117 Gm3 yr 1) and the Ganges river basin (108 Gm3 yr 1). The two basins together account for 25 % of the blue water footprint related to global crop production. Globally, rain-fed agriculture has a water footprint of 5173 Gm3 yr 1 (91 % green, 9 % grey); irrigated agriculture has a water footprint of 2230 Gm3 yr 1 (48 % gre
The water footprint of electricity from hydropower
M. M. Mekonnen,A. Y. Hoekstra
Hydrology and Earth System Sciences Discussions , 2011, DOI: 10.5194/hessd-8-8355-2011
Abstract: Hydropower accounts for about 16% of the world's electricity supply. It has been debated whether hydroelectric generation is merely an in-stream water user or whether it also consumes water. In this paper we provide scientific support for the argument that hydroelectric generation is in most cases a significant water consumer. The study assesses the blue water footprint of hydroelectricity – the water evaporated from manmade reservoirs to produce electric energy – for 35 selected sites. The aggregated blue water footprint of the selected hydropower plants is 90 Gm3 yr 1, which is equivalent to 10% of the blue water footprint of global crop production in the year 2000. The total blue water footprint of hydroelectric generation in the world must be considerably larger if one considers the fact that this study covers only 8% of the global installed hydroelectric capacity. Hydroelectric generation is thus a significant water consumer. The average water footprint of the selected hydropower plants is 68 m3 GJ 1. Great differences in water footprint among hydropower plants exist, due to differences in climate in the places where the plants are situated, but more importantly as a result of large differences in the area flooded per unit of installed hydroelectric capacity. We recommend that water footprint assessment is added as a component in evaluations of newly proposed hydropower plants as well as in the evaluation of existing hydroelectric dams, so that the consequences of the water footprint of hydroelectric generation on downstream environmental flows and other water users can be evaluated.
The green, blue and grey water footprint of crops and derived crop products
M. M. Mekonnen,A. Y. Hoekstra
Hydrology and Earth System Sciences Discussions , 2011, DOI: 10.5194/hessd-8-763-2011
Abstract: This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996–2005. The assessment is global and improves upon earlier research by taking a high-resolution approach, estimating the water footprint of 126 crops at a 5 by 5 arc min grid. We have used a grid-based dynamic water balance model to calculate crop water use over time, with a time step of one day. The model takes into account the daily soil water balance and climatic conditions for each grid cell. In addition, the water pollution associated with the use of nitrogen fertilizer in crop production is estimated for each grid cell. The crop evapotranspiration of additional 20 minor crops is calculated with the CROPWAT model. In addition, we have calculated the water footprint of more than two hundred derived crop products, including various flours, beverages, fibres and biofuels. We have used the water footprint assessment framework as in the guideline of the water footprint network. Considering the water footprints of primary crops, we see that global average water footprint per ton of crop increases from sugar crops (roughly 200 m3 ton 1), vegetables (300 m3 ton 1), roots and tubers (400 m3 ton 1), fruits (1000 m3 ton 1), cereals} (1600 m3 ton 1), oil crops (2400 m3 ton 1) to pulses (4000 m3 ton 1). The water footprint varies, however, across different crops per crop category and per production region as well. Besides, if one considers the water footprint per kcal, the picture changes as well. When considered per ton of product, commodities with relatively large water footprints are: coffee, tea, cocoa, tobacco, spices, nuts, rubber and fibres. The analysis of water footprints of different biofuels shows that bio-ethanol has a lower water footprint (in m3 GJ 1) than biodiesel, which supports earlier analyses. The crop used matters significantly as well: the global average water footprint of bio-ethanol based on sugar beet amounts to 51 m3 GJ 1, while this is 121 m3 GJ 1 for maize. The global water footprint related to crop production in the period 1996–2005 was 7404 billion cubic meters per year (78% green, 12% blue, 10% grey). A large total water footprint was calculated for wheat (1087 Gm3 yr 1), rice (992 Gm3 yr 1) and maize (770 Gm3 yr 1). Wheat and rice have the largest blue water footprints, together accounting for 45% of the global blue water footprint. At country level, the total water footprint was largest for India (1047 Gm3 yr 1), China (967 Gm3 yr 1) and the USA (826 Gm3 yr 1). A relatively large total blue water
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