Sample records for yoru domyaku koka
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Stock assessment of fishery target species in Lake Koka, Ethiopia.
Tesfaye, Gashaw; Wolff, Matthias
2015-09-01
Effective management is essential for small-scale fisheries to continue providing food and livelihoods for households, particularly in developing countries where other options are often limited. Studies on the population dynamics and stock assessment on fishery target species are thus imperative to sustain their fisheries and the benefits for the society. In Lake Koka (Ethiopia), very little is known about the vital population parameters and exploitation status of the fishery target species: tilapia Oreochromis niloticus, common carp Cyprinus carpio and catfish Clarias gariepinus. Our study, therefore, aimed at determining the vital population parameters and assessing the status of these target species in Lake Koka using length frequency data collected quarterly from commercial catches from 2007-2012. A total of 20,097 fish specimens (distributed as 7,933 tilapia, 6,025 catfish and 6,139 common carp) were measured for the analysis. Von Bertalarffy growth parameters and their confidence intervals were determined from modal progression analysis using ELEFAN I and applying the jackknife technique. Mortality parameters were determined from length-converted catch curves and empirical models. The exploitation status of these target species were then assessed by computing exploitation rates (E) from mortality parameters as well as from size indicators i.e., assessing the size distribution of fish catches relative to the size at maturity (Lm), the size that provides maximum cohort biomass (Lopt) and the abundance of mega-spawners. The mean value of growth parameters L∞, K and the growth performance index ø' were 44.5 cm, 0.41/year and 2.90 for O. niloticus, 74.1 cm, 0.28/year and 3.19 for C. carpio and 121.9 cm, 0.16/year and 3.36 for C. gariepinus, respectively. The 95 % confidence intervals of the estimates were also computed. Total mortality (Z) estimates were 1.47, 0.83 and 0.72/year for O. niloticus, C. carpio and C. gariepinus, respectively. Our study suggest that
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Eliku, Temesgen; Leta, Seyoum
2017-04-01
Heavy metal accumulation in agricultural crops has grown a major concern globally as a result of a significant health impact on human. The quantification of heavy metals (Cd, Pb, Cr, Zn, Cu, and Ni) in the soil and vegetables at two sites (Koka and Wonji Gefersa) was done using flame atomic absorption spectrophotometer. The mean concentrations of heavy metals in vegetable fields' soil samples obtained from Koka were higher for Pb, Cr, Zn, Cu, and Ni. The overall results of soil samples ranged 0.52-0.93, 13.6-27.3, 10.0-21.8, 44.4-88.5, 11.9-30.3, and 14.7-34.5 mg kg -1 for Cd, Pb, Cr, Zn, Cu, and Ni, respectively. The concentrations of heavy metals were maximum for Cd (0.41 ± 0.03 mg kg -1 ), Pb (0.54 ± 0.11 mg kg -1 ), Zn (14.4 ± 0.72 mg kg -1 ), Cu (2.84 ± 0.27 mg kg -1 ), and Ni (1.09 ± 0.11 mg kg -1 ) in Cabbage and for Cr (2.63 ± 0.11 mg kg -1 ) in green pepper. The result indicated that Cd has high transfer factor value and Pb was the lowest. The transfer pattern for heavy metals in different vegetables showed a trend in the order: Cd > Zn > Cu > Cr > Ni > Pb. Among different vegetables, cabbage showed the highest value of metal pollution index and bean had the lowest value. Hazard index of all the vegetables was less than unity; thus, the consumption of these vegetables is unlikely to pose health risks to the target population.
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Water resources implications of integrating malaria control into the operation of an Ethiopian dam
NASA Astrophysics Data System (ADS)
Reis, Julia; Culver, Teresa B.; McCartney, Matthew; Lautze, Jonathan; Kibret, Solomon
2011-09-01
This paper investigates the water resources implications of using a method of hydrological control to reduce malaria around the Koka reservoir in central Ethiopia. This method is based on recent findings that malaria is transmitted from the shoreline of the Koka reservoir, and on a similar method that was used to control malaria some 80 yr ago in the United States. To assess the feasibility of implementing hydrological control at Koka, we considered the potential impact of the modified management regime on the benefits derived from current uses of the reservoir water (i.e., hydropower, irrigation, flood control, water supply, and downstream environmental flows). We used the HEC-ResSim model to simulate lowering the reservoir by a rate designed to disrupt larval development, which is expected to reduce the abundance of adult mosquito vectors and therefore reduce malaria transmission during the season in which transmission of the disease peaks. A comparison was made of major reservoir uses with and without the malaria control measure. In the 26-yr simulation, application of the malaria control measure increased total average annual electricity generation from 87.6 GWh × y-1 to 92.2 GWh × y-1 (i.e., a 5.3% increase) but resulted in a small decline in firm power generation (i.e., guaranteed at 99.5% reliability) from 4.16 MW to 4.15 MW (i.e., a 0.2% decrease). Application of the malaria control measure did not impact the ability of the reservoir to meet downstream irrigation demand and reduced the number of days of downstream flooding from 28 to 24 d. These results indicate that targeted use of hydrological control for malaria vector management could be undertaken without sacrificing the key benefits of reservoir operation.
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Trace element mobility and transfer to vegetation within the Ethiopian Rift Valley lake areas.
Kassaye, Yetneberk A; Skipperud, Lindis; Meland, Sondre; Dadebo, Elias; Einset, John; Salbu, Brit
2012-10-26
To evaluate critical trace element loads in native vegetation and calculate soil-to-plant transfer factors (TFs), 11 trace elements (Cr, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Pb and Mn) have been determined in leaves of 9 taxonomically verified naturally growing terrestrial plant species as well as in soil samples collected around 3 Ethiopian Rift Valley lakes (Koka, Ziway and Awassa). The Cr concentration in leaves of all the plant species was higher than the "normal" range, with the highest level (8.4 mg per kg dw) being observed in Acacia tortilis from the Lake Koka area. Caper species (Capparis fascicularis) and Ethiopian dogstooth grass (Cynodon aethiopicus) from Koka also contained exceptionally high levels of Cd (1 mg per kg dw) and Mo (32.8 mg per kg dw), respectively. Pb, As and Cu concentrations were low in the plant leaves from all sites. The low Cu level in important fodder plant species (Cynodon aethiopicus, Acacia tortilis and Opuntia ficus-indicus) implies potential deficiency in grazing and browsing animals. Compared to the Canadian environmental quality guideline and maximum allowable concentration in agricultural soils, the total soil trace element concentrations at the studied sites are safe for agricultural crop production. Enrichment factor was high for Zn in soils around Lakes Ziway and Awassa, resulting in moderate to high transfer of Zn to the studied plants. A six step sequential extraction procedure on the soils revealed a relatively high mobility of Cd, Se and Mn. Strong association of most trace elements with the redox sensitive fraction and mineral lattice was also confirmed by partial redundancy analysis. TF (mg per kg dw plants/mg per kg dw soil) values based on the total (TF(total)) and mobile fractions (TF(mobile)) of soil trace element concentrations varied widely among elements and plant species, with the averaged TF(total) and TF(mobile) values ranging from 0.01-2 and 1-60, respectively. Considering the mobile fraction in soils should
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Deribe, Ermias
2018-05-21
Organic pollutants in the Ethiopian Rift Valley Lakes are the major factors that contribute to severe environmental problem. SPMDs were deployed for the analysis of selected organic pollutants for 1 month at 2 sites in Lakes Hawassa, Ziway and Koka, Ethiopia. From SPMDs placed in the three lakes, the predominant OCPs were DDT which comprise 67% and followed by endosulfan 23% of the total organochlorine pesticides (OCPs) retrieved. The highest level of OCPs, in general, was found in the SPMDs deployed in Lake Ziway with the mean concentration of 308.5 ng/SPMD. However, the concentrations of polychlorinated biphenyls (PCBs) were the highest in the SPMDs deployed in Lake Hawassa with mean concentration of 50.2 ng/SPMD. Spatial variation on the accumulation of OCPs and PCBs among the lakes depends on the shoreline activities, distance of the lakes from point and non-point sources, and the biofouling factors.
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Hydrology and Mosquito Population Dynamics around a Hydropower Reservoir in Africa
NASA Astrophysics Data System (ADS)
Endo, N.; Eltahir, E. A.
2013-12-01
Malaria is associated with dams because their reservoirs provide mosquitoes, the vector of malaria, with permanent breeding sites. The risk of contracting malaria is likely to be enhanced following the increasing trend of hydropower dam construction to satisfy the expanding energy needs in developing countries. A close examination of its adverse health impacts is critical in the design, construction, and operation phases. We will present results of extensive field studies in 2012 and 2013 around the Koka Reservoir, Ethiopia. The results uncover the importance of reservoir management especially after the rainy seasons. Furthermore, we show the capability of a newly modified hydrology, entomology and malaria transmission simulator, HYDREMATS (Bomblies et al, 2008), and its potential as a tool for evaluating environmental management strategies to control malaria. HYDREMATS was developed to represent how the hydrology in nearby villages is impacted by the reservoir system, and the role of different types of vector ecologies associated with different Anopheles mosquito species. The hydrology component of HYDREMATS simulates three different mosquito breeding habitats: rain-fed pools, groundwater pools, and shoreline water. The entomology component simulates the life cycles of An. funestus and An. arabiensis, the two main vectors around the reservoir. The model was calibrated over the 2012-2013 period. The impact of reservoir water level management on the mosquito population is explored based on numerical model simulations and field experiments.
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NGA Tukitanga Mai Koka Ki Tona Ira: Maori mothers and child to mother violence.
Ryan, Ripekapaia Gloria; Wilson, Denise
2010-11-01
In common with other indigenous women Māori mothers risk illness, harm, and possible death when abused and intimidated by their children. Yet women suffering child to mother violence are silenced by their fear and shame, and endeavour to minimise the effects of this form of abuse. A qualitative descriptive research design using kaupapa Māori methodology was adopted to explore the experiences of Māori mothers who had been abused by a son or daughter. During semi-structured interviews with five Māori women experiences of abuse by a child, and its impact on the whānau/family were recorded. Interview transcripts were analysed thematically, and three key themes emerged: behind closed doors, my child and a new journey. These Māri mothers carried the secret of the violence alone; keeping it behind closed doors while paradoxically protecting their abusive child. Nonetheless, these mothers reached a point where they chose to undertake a new journey, one that involved telling their story, reconnecting with their indigenous roots, and engaging in healing activities. The mothers' experiences highlight a lack of support and responsiveness by support and health agencies. Regardless of these negative experiences with support agencies, we highlight the important role nurses have in facilitating whānau ora (family wellbeing) for these women. This research contributes an indigenous perspective to the growing literature on child to mother violence, and provides direction for future research.
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Modelling and observing the role of wind in Anopheles population dynamics around a reservoir.
Endo, Noriko; Eltahir, Elfatih A B
2018-01-25
Wind conditions, as well as other environmental conditions, are likely to influence malaria transmission through the behaviours of Anopheles mosquitoes, especially around water-resource reservoirs. Wind-induced waves in a reservoir impose mortality on aquatic-stage mosquitoes. Mosquitoes' host-seeking activity is also influenced by wind through dispersion of [Formula: see text]. However, no malaria transmission model exists to date that simulated those impacts of wind mechanistically. A modelling framework for simulating the three important effects of wind on the behaviours of mosquito is developed: attraction of adult mosquitoes through dispersion of [Formula: see text] ([Formula: see text] attraction), advection of adult mosquitoes (advection), and aquatic-stage mortality due to wind-induced surface waves (waves). The framework was incorporated in a mechanistic malaria transmission simulator, HYDREMATS. The performance of the extended simulator was compared with the observed population dynamics of the Anopheles mosquitoes at a village adjacent to the Koka Reservoir in Ethiopia. The observed population dynamics of the Anopheles mosquitoes were reproduced with some reasonable accuracy in HYDREMATS that includes the representation of the wind effects. HYDREMATS without the wind model failed to do so. Offshore wind explained the increase in Anopheles population that cannot be expected from other environmental conditions alone. Around large water bodies such as reservoirs, the role of wind in the dynamics of Anopheles population, hence in malaria transmission, can be significant. Modelling the impacts of wind on the behaviours of Anopheles mosquitoes aids in reproducing the seasonality of malaria transmission and in estimation of the risk of malaria around reservoirs.
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Murayama, Hiroshi; Taguchi, Atsuko; Ryu, Shuhei; Nagata, Satoko; Murashima, Sachiyo
2012-09-01
Japanese social security systems and institutions for the elderly, as well as the general attitude toward elderly care services among the Japanese population, have been undergoing a dramatic change. By examining the association between institutional trust, which is a representative element of social capital, and anxiety regarding receiving elderly care, we can uncover clues toward building a more robust social security system for the elderly. This study examines the relationship between institutional trust, in the national social security and municipal healthcare systems for the elderly, and anxiety with respect to receiving elderly care among the general Japanese population. A cross-sectional survey was conducted using a self-administered questionnaire that was returned by mail in January and February 2005. The target population was 4735 community residents aged 20-75 years, who lived in the city of Koka, Shiga, Japan. A total of 2264 questionnaires were included in the analysis. A binominal logistic regression analysis showed that responses of 'trust' [odds ratio (OR): 2.09, 95% confidence interval (95% CI): 1.01-4.30] and 'strongly trust' (OR: 3.80, 95% CI: 1.55-9.31) for the national system were associated with not having anxiety regarding elderly care, compared with the reference category of feeling strongly distrust. However, trust in the municipal system showed no association with this anxiety. These results indicate the importance of developing strategies to increase a common trust in the national care services for the elderly to reduce the anxiety people feel regarding whether they will be able to receive elderly care when required.
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2013-01-01
Background Health promotion volunteers (HPVs) who are expected to function as leaders in promoting community health in Japan feel both satisfaction and burden associated with their community engagement activities. The purposes of this study were 1) to describe the prevalence of volunteers with differing levels of activity satisfaction and burden; 2) to examine the association between satisfaction and burden with activity involvement and persistence, and life satisfaction; and 3) to explore associated factors by satisfaction/burden levels among Japanese HPVs. The research question for this study was as follows: What is the relationship between activity satisfaction and burden among HPV? Methods A mail-in self-administered questionnaire survey was distributed to 604 HPVs in the cities of Konan and Koka, Shiga Prefecture, central Japan, in September 2005. Questions encompassed demographic data, variables regarding HPV activity such as organizational environment, social support, and the relationship with the neighborhood association, and overall satisfaction and burden related to the activity. Results The analyzed sample comprised 422 HPVs. Those with high satisfaction/low burden represented the largest number of study participants (group A; 38.4%). HPVs with high satisfaction/high burden (group B), low satisfaction/low burden (group C), and low satisfaction/high burden (group D) represented 23.0%, 11.1%, and 27.5% of participants, respectively. HPVs in groups A and B reported a greater total number of activities undertaken than those in group C. However, HPVs in group A had higher life satisfaction than those in groups C and D. Multinomial logistic regression analysis used to explore group differences showed that HPVs in group B had lower initial motivation and received less social support from colleagues, and those in group C felt the head of the neighborhood association was uncooperative. Those in group D had lower initial motivation, rated their organizational
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Efficacy of a non-drinking mental simulation intervention for reducing student alcohol consumption.
Conroy, Dominic; Sparks, Paul; de Visser, Richard
2015-11-01
days' per week (NHS, 2014). Benefits of, and strategies involved in, social non-drinking exist (Conroy & de Visser, 2014). Mental simulation interventions may help reduce student drinking (Hagger, Lonsdale, & Chatzisarantis, 2012; Hagger, Lonsdale, Koka et al., 2012). What does this study add? Demonstrates efficacy of a novel 'non-drinking' mental simulation exercise. Suggests that healthier alcohol prototypes can be encouraged via a health promotion intervention. Shows potential utility of 'episodic non-drinking' as an indicator of health-adherent drinking. © 2015 The British Psychological Society.
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Wilson, G. Glenn; Ryder, Darren; Tekie, Habte; Petros, Beyene
2018-01-01
Background Water level management has been suggested as a potential tool to reduce malaria around large reservoirs. However, no field-based test has been conducted to assess the effect of water level management on mosquito larval abundance in African settings. The objective of the present study is to evaluate the effects of water level drawdown rates on mosquito larval abundance. Methods Twelve experimental dams were constructed on the foreshore of the Koka Dam in Ethiopia. These were grouped into four daily water drawdown treatments, each with three replicates: no water-level drawdown (Group 1; Control), 10 mm.d-1 (Group 2), 15 mm.d-1 (Group 3) and 20 mm.d-1 (Group 4). Larval sampling was conducted weekly for a period of 6 weeks each in the main malaria transmission season (October to November 2013) and subsequent dry season (February to March 2014). Larval densities were compared among treatments over time using repeated measures Analysis of Variance (ANOVA). Results A total of 284 Anopheles mosquito larvae were collected from the experimental dams during the study period. Most (63.4%; n = 180) were collected during the main malaria transmission season while the remaining (36.6%; n = 104) were collected during the dry season. Larvae comprised four Anopheles species, dominated by Anopheles arabiensis (48.1% of total larval samples; n = 136) and An. pharoensis (33.2%; n = 94). Mean larval density was highest in control treatment dams with stable water levels throughout the study, and decreased significantly (P < 0.05) with increasing water drawdown rates in both seasons. During the main transmission season, anopheline larval density was generally lower by 30%, 70% and 84% in Groups 2, Group 3 and Group 4, respectively, compared with the control dams (Group 1). In the dry season, larval density was reduced by 45%, 70% and 84% in Groups 2, Group 3 and Group 4, respectively, when compared to the control dams. Conclusion Increased water drawdown rates were associated
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Dugassa, Sisay; Medhin, Girmay; Balkew, Meshesha; Seyoum, Aklilu; Gebre-Michael, Teshome
2009-10-01
A study was undertaken to evaluate the impact of traditional application methods of mosquito repellent plants in the reduction of the human-vector contact of malaria vectors in central Ethiopia. The plants (Corymbia citriodora, Eucalyptus camaldulensis, Ocimum suave and Ocimum basilicum) were tested by thermal expulsion and direct burning on traditional stoves in the field against two important malaria vectors in Ethiopia (Anopheles arabiensis and An. pharoensis). A Latin-square design was applied for randomly assigning the treatment plants and control to experimental houses over different nights. The percentage repellency of each candidate plant by both application methods was estimated from the catches of mosquitoes in the treatment and control houses. On direct burning of the plants, O. basilicum showed the highest percentage repellency (73.11%, P<0.001) and E. camaldulensis the least repellency (65.29%, P<0.001) against An. arabiensis. By the same method of application, C. citriodora on the other hand gave the highest repellency (72.87%, P<0.001) while E. camaldulensis was still the least repellent plant (66.60%, P<0.001) against An. pharoensis. On thermal expulsion, C. citriodora exhibited the highest repellency (78.69%, P<0.001) while E. camaldulensis was the lowest repellent plant (71.91%, P<0.001) against An. arabiensis. Against An. pharoensis, C. citriodora gave the highest repellency (72.9%, P<0.001) while E. camaldulensis still gave the least repellency (72.2%, P<0.001) on the same method of application. All the tested plants by both methods of application gave partial but significant protection (>65%) against the house-entry and biting of two important malaria vectors in Ethiopia, and thus have a potential to be used at least as supplements to other control methods. However, feasibility and actual impact on disease transmission need to be known on these and other potentially useful plants.