Assessment of Stormwater Drainage System for Small Urban Watershed: Case of Shambu Town, Oromia Region, Ethiopia

Stormwater runoff in a small urban watershed is one of the major challenging issues facing many countries where financial capacity is very weak to provide sufficient drainage systems. This study aims to assess the stormwater drainage system in the small urban watershed as a case study of Shambu town, Oromia Region, Ethiopia. The main objective of this study was to assess whether this excess stormwater runoff is due to hydrological change or insufficient hydraulic design of the existing drainage system in the town. The existing drainage system in this small urban watershed was analyzed by statistical analysis and the main purpose of this was to know whether the designed drainage systems were sufficient hydraulically. The existing drainage system in this small urban watershed was analyzed by statistical analysis and the main purpose of this was to know whether the designed drainage systems were sufficient hydraulically. The existing design document was taken in this analysis and field analysis also made to check whether the drainage was constructed according to the specification. The area also analyzed hydrologically by delineating the watershed using ArcSWAT and the peak discharge was computed the outlet of the watershed using Rational method.  Some data such runoff coefficient and manning’s values were also generated from the watershed based on the reality on the ground. The two results from hydrological and hydraulic models were compared and that of peak discharge obtained from rational method became greater than of the Peak discharge obtained from existing drainage measurement. Therefore, in this study it was concluded that since the watershed is steep in slope, it is contributing additional runoff to this small urban watershed, additional new 50% of the existing drainage system and rehabilitation works should be implemented to modify the draining capacity of the existing scheme. Additionally, managing and improper construction alignment problem in the existing system were identified, so to control this challenge periodic cleaning and modification of slope is recommended. Keywords: Hydraulic Model, Hydrological Model, Runoff, Small Urban Watershed, Stormwater DOI: 10.7176/CER/12-9-01 Publication date:September 30th 202

Sustainable Use of Soil and Water Conservation Technologies and Its Determinants: The Case of the Handosha Watershed, Omo-Gibe River Basin, Ethiopia

For the past forty years, Ethiopia has been promoting sustainable land management activities to enhance agricultural productivity. This study was intended to identify the factors determining farmers’ adoption and continued use of soil bund measures in the Handosha watershed, Omo-Gibe river basin. A multistage sampling technique was used to select 340 households using the Heckman sample selection model. A total of 235 (69.12%) households adopted soil bunds, but only 89 (37.87%) of them were sustainably practicing soil bunds on their farm plots. Most adopters widely practiced soil bunds (49.42%), followed by stone bund (15.9%), and Fanyajuu (10%). The empirical results of the Heckman sample selection model showed that the farming experience, land tenure security, and perception of profitability of conservation measures were significantly positively affected the adoption of soil bund. Whereas, farm plot size and participation in off farm activities significantly negatively influenced the adoption of soil bund. Sustainable use of soil bund measures were significantly positively influenced by land tenure security, family size, and frequency of extension contact, whereas the distance between farm plots and home, and farm plot size were negatively affected. As a result, a design of agro-ecological-based soil and water conservation (SWC) measures was essential in reducing farmland vulnerability to soil erosion and food insecurity. It has been concluded that conservation practices should not only focus on the implementation and biophysical factors but also consider the socioeconomic interests of the farmers to improve the sustainable use of conservation technologies

Combining Ability in Maize Lines for Agronomic Traits and Resistance to Weevil (Sithophilus zeamais Motschulky)

In Ethiopia, heavy losses to stored maize are inflicted by various insect pests including Sitophilus weevils and Sitotroga cereallela. This study was  conducted to determine the combining ability of five introduced inbred lines in agronomic traits and maize weevil resistance by crossing them with three  testers using line × tester mating system. These crosses were then evaluated in tri-plicated randomized complete blocks at Bako Agricultural Research  Center in 2003. Samples (50 g) of the F2 full-sib grain of the genotypes were further tested for weevil resistance under a no-choice laboratory  environment. Mean squares due to general (GCA) and specific (SCA) combining ability were significant for most of the agronomic traits. However, GCA  mean squares predominated in all weevil resistance traits. The lines varied in their GCA effects for the various agronomic traits considered. However, all of  them were found to be poor general combiners for grain yield, although certain crosses gave acceptable yield. The lines SZSYNA99-F2-133-2-3,  SZSYNA99-F2-33-4-1, SZSYNA99-F2-33-4-2 and SZSYNB99-F2-98-4-3 exhibited desirable GCA effects for most of the resistance traits. Overall, this study  suggested the existence of heritable weevil resistance quantitative traits that can be used in weevil resistance breeding programs.&nbsp

The Combining Ability of Maize Inbred Lines for Grain Yield and Reaction to Grey Leaf Spot Disease

Considering the potential threat of grey leaf spot (GLS) to maize production, the national maize research program of Ethiopia has been screening local and exotic maize genotypes against the disease as the commercially available and advanced inbred lines susceptible to GLS. This experiment was, therefore, conducted to investigate the general (GCA) and specific (SCA) combining ability of selected maize inbred lines for grain yield and GLS disease resistance. Eight maize inbred lines with contrasting reactions to GLS were crossed in diallel mating to generate 28 hybrids. The parents and hybrids were evaluated in randomised complete block design with three replications at Bako, Ethiopia in 2001 and 2002. Significant differences were observed among entries for disease parameters, plant height, days to maturity and grain yield. GCA and SCA effects were significant for all traits. Mean squares due to GCA were higher than that of SCA for all traits, except for grain yield, indicating the predominance of non-additive gene effect for grain yield and additive gene effect for other traits. Some inbred lines with resistance reaction have been identified. Parental lines 143-5-i and CML-387 showed a better per se performance and GCA effects while A-7016 was the worst parent for GLS disease reaction. Inbred parent 143-5-i was the best general combiner for grain yield; but a poor general combiner for plant height and days to maturity. The information from this study will be useful for the development of high-yielding and GLS disease-resistant maize varieties

Advanced modeling and optimizing for surface sterilization process of grape vine (Vitis vinifera) root stock 3309C through response surface, artificial neural network, and genetic algorithm techniques

In vitro, sterilization is one of the key components for proceeding with plant tissue cultures. Since the effectiveness of sterilization has a direct impact on the culture's final outcomes, there is a crucial need for optimization of the sterilization process. However, compared with traditional optimizing methods, the use of computational approaches through artificial intelligence-based process modeling and optimization algorithms provides a precise optimal condition for in vitro culturing. This study aimed to optimise in vitro sterilization of grape rootstock 3309C using RSM, ANN, and genetic algorithm (GA) techniques. In this context, two output responses, namely, Clean Culture and Explant Viability, were optimised using the models developed by RSM and ANN, followed by a GA, to obtain a globally optimal solution. The most influential independent factors, such as HgCl2, NaOCl, AgNO3, and immersion time, were considered input variables. The significance of the developed models was investigated with statistical and non-statistical techniques and was optimised to determine the significance of selected inputs. The optimal clean culture of 91%, and the explant viability of 89% can be obtained from 1.62% NaOCl at a 13.96 min immersion time, according to MLP-NSGAII. Sensitivity analysis revealed that the clean culture and explant viability were less sensitive to AgNO3 and more sensitive to immersion time. Results showed that the differences between the GA predicted and validation data were significant after the performance validation of predicted and optimised sterilising agents with immersion time combinations were tested. In general, GA, a potent methodology, may open the door to the development of new computational methods in plant tissue culture

Flexible Bayesian semiparametric mixed-effects model for skewed longitudinal data

Abstract Background In clinical trials and epidemiological research, mixed-effects models are commonly used to examine population-level and subject-specific trajectories of biomarkers over time. Despite their increasing popularity and application, the specification of these models necessitates a great deal of care when analysing longitudinal data with non-linear patterns and asymmetry. Parametric (linear) mixed-effect models may not capture these complexities flexibly and adequately. Additionally, assuming a Gaussian distribution for random effects and/or model errors may be overly restrictive, as it lacks robustness against deviations from symmetry. Methods This paper presents a semiparametric mixed-effects model with flexible distributions for complex longitudinal data in the Bayesian paradigm. The non-linear time effect on the longitudinal response was modelled using a spline approach. The multivariate skew-t distribution, which is a more flexible distribution, is utilized to relax the normality assumptions associated with both random-effects and model errors. Results To assess the effectiveness of the proposed methods in various model settings, simulation studies were conducted. We then applied these models on chronic kidney disease (CKD) data and assessed the relationship between covariates and estimated glomerular filtration rate (eGFR). First, we compared the proposed semiparametric partially linear mixed-effect (SPPLM) model with the fully parametric one (FPLM), and the results indicated that the SPPLM model outperformed the FPLM model. We then further compared four different SPPLM models, each assuming different distributions for the random effects and model errors. The model with a skew-t distribution exhibited a superior fit to the CKD data compared to the Gaussian model. The findings from the application revealed that hypertension, diabetes, and follow-up time had a substantial association with kidney function, specifically leading to a decrease in GFR estimates. Conclusions The application and simulation studies have demonstrated that our work has made a significant contribution towards a more robust and adaptable methodology for modeling intricate longitudinal data. We achieved this by proposing a semiparametric Bayesian modeling approach with a spline smoothing function and a skew-t distribution

Additional file 1 of Flexible Bayesian semiparametric mixed-effects model for skewed longitudinal data

Additional file 1: Appendix A. Convergence diagnostic checking results. Figure A.1. Trace plots of some representative parameters from the chosen model. Figure A.2. Autocorrelation function plots (a) and BGR plots (b) of some representative parameters. Table A.1. Results of the Geweke's test of convergence. The computed value of the test statistic for each parameter from the chosen model. Appendix B. Skew Distributions

Wildlife roadkill in Southwestern Ethiopia: Hotspots, drivers, and victim species

Wildlife-vehicle collision (WVC) is one of the major causes of wildlife mortality and a concern for conservationists worldwide. The study of roadkill data that can be used to develop appropriate measures and strategies for both wildlife conservation and traffic safety to mitigate the WVC and animals' mortality. Extensive studies have been conducted in the developed countries on the identification of WVC hotspots and its potential impact; however, less attention is given in developing countries. Because of this, the problem is not well understood in developing countries. This study was intended to identify victim species, hotspot areas for roadkill, and factors that contribute to WVC in Jimma Zone, along three roads leading from Jimma City. Data were collected using a citizen science approach and a skilled man power road survey (March–September 2022) to document the number and type of species killed. Three road segments (135 km in total) were surveyed weekly as a baseline for future research. All statistical analyses were carried out using R-software. In the present study, a total of 84 roadkill specimens were collected from 16 different mammal species, of which 85.7% were medium-sized carnivores. The findings showed that Jackals (Canis mesomalis and Canis adustus) were the most frequently killed species (25%, n is 21), followed by Civettictis civetta (22.62%, n is 19). The study revealed that the major factors causing collisions include habitat type (forest cover) and wildlife behavior (nocturnal or diurnal). Further, the study revealed that the majority of WVC occurred at night (dusk) and at dawn in areas that are covered with dense forests. To minimize the potential risks of WVC and animals’ mortality, we suggest putting warning signs in hotspot areas where roadkill usually occur frequently. In addition, we recommend creating awareness among drivers, traffic police, and all communities about the negative impacts and consequences of collisions on the ecological and economic value of wildlife

Forest plot of the association between availability of newborn resuscitation guidelines and training with knowledge of newborn resuscitation among health care providers in East Africa.

Forest plot of the association between availability of newborn resuscitation guidelines and training with knowledge of newborn resuscitation among health care providers in East Africa.</p