Effect of the soil water characteristic curve on the stability of partially saturated slopes

Rainfall significantly contributes to slope failure in unsaturated slopes by causing a reduction in matrix suction and subsequent decline in shear strength of the soil. Understanding the relationship between matrix suction and moisture content is crucial for describing the hydraulic behavior of unsaturated soil, typically represented by the Soil-Water Characteristic Curve (SWCC). This study focuses on assessing how SWCC affects the stability of partially saturated soil during infiltration us ing fully coupled-flow deformation analysis in PLAXIS 2D. To enhance efficiency and automate analyses for numerous iterations, PLAXIS-remote scripting is utilized.Parameters that quantify the SWCC are utilized to depict the properties of unsaturated soils. The Van- Genuchten parameters, which describe the hydraulic behavior of unsaturated soil, have been determined based on the SWCC. Furthermore, the impact of Van Genuchten parameters (ga , gn) that best fit the SWCC on the stability of unsaturated soil under rainfall conditions has been studied. The slope stability under infiltration is initially examined based on the derived VG parameters. Subsequently, the impact of VG parameters on the stability of unsaturated slopes is assessed by determining five different values for each parameter:ga and gn. These values are utilized to generate five unique sets of VG parameters, resulting in 25 combinations. The stability of the unsaturated slope under the effect of rainfall is then evaluated for these 25 combinations of VG parameters. In addition to hydraulic parameters, factors such as the geometry of the slope and the shear strength properties of the soil also play a significant role in influencing the stability of unsaturated slopes. Therefore, a sensitivity analysis is conducted by varying the slope geometry and shear strength properties to explore the impact of 25 different combinations of Van Genuchten parameters. The resulting values of FOS are then compared with the original slope geometry and shear strength properties for all 25 combinations of Van Genuchten parameters under the effect of rainfall, in order to investigate the slope stability.Upon increasing the values of ga and gn, the FOS of the slope significantly decreases under the influence of rainfall. Moreover, sensitivity analysis results indicate that the stability of an unsaturated slope under consistent rainfall infiltration is directly correlated with the VG parameters and shear strength parameters, while being inversely proportional to the slope’s geometry

Bed nets for malaria prevention under field conditions in Ethiopia: : Durability, use, and impact on spatial variation of malaria

Background: Despite a remarkable achievement in reducing malaria and in scaling up vector control intervention using long-lasting insecticidal nets (LLINs) in the last 15 years, malaria remains a significant public health problem in Ethiopia. To maximize the benefit of LLINs for malaria reduction, LLINs should provide a serviceable life, and people at risk for malaria should use them. However, field studies show considerable variation in both LLIN serviceable life and utilization in different settings. Moreover, malaria transmission is highly heterogeneous in different geographic locations and over time due to variations in risk factors. To further reduce the malaria burden, it is important to understand the factors that affect malaria clustering. For example, at a micro-geographic scale, it is crucial to target interventions in so-called hotspots (areas with a higher proportion of malaria cases than the overall population). In Ethiopia, several studies have evaluated the spatiotemporal clustering of malaria; however, with the exception of a single study in a southern Ethiopian village with a high malaria infection rate, none quantified the impact of malaria control interventions on the observed clustering. Hence, spatial variation in malaria transmission according to different intervention types in areas with low malaria transmission is not yet fully understood. To fill this knowledge gap, we examined the impact of LLIN use, indoor residual spraying (IRS), and combined LLIN and IRS use on spatial clustering of malaria in settings with low malaria transmission. In summary, evaluating the lifespan of LLINs, the extent of LLIN utilization by people at risk of malaria infection and the impacts of LLIN use alone, IRS use alone or the combination of LLINs and IRS on spatial clustering of malaria, could aid in designing efficient and effective malaria control strategies. General objective: The overall aim of this study was to assess LLINs in real-life field conditions and their impact on spatial variation of malaria in an area targeted for a cluster- randomized controlled trial for malaria prevention in southern-central Ethiopia. The specific objectives: 1) To determine the durability of LLINs under field conditions in terms of attrition, physical integrity, functional survival and bio-efficacy; 2) to assess LLIN ownership and use over time and identify factors associated with LLIN use; 3) to assess malaria infection clusters in areas with LLIN use; and 4) to assess malaria infection clusters in relation to IRS alone or a combination of LLIN and IRS interventions. Methods: We followed up a cohort of 1,532 LLINs every six months from October 2014 to November 2016 to assess their attrition, physical integrity and functional survival under field conditions. In addition, 120 randomly selected LLINs were tested for bio-efficacy (Paper I). In Paper II, we followed a cohort of 17,142 individuals via weekly home visits for 121 weeks to document their LLIN use. We also conducted a survey at 110 weeks after LLIN distribution to determine LLIN ownership. In Paper III, we followed a cohort of 34,548 persons every week from October 2014 to January 2017 and used active and passive case detection mechanisms to identify clinical malaria episodes. A discrete Poisson model was used to identify high rates of spatial, temporal and spatiotemporal clustering of malaria using SaTScan software v9.4.2 (Paper III). Results: In Paper I, we observed high attrition and low functional survival of LLINs in the study period. LLIN attrition was mainly due to disposal. The median functional survival time of the LLINs was only 12 months. The PermaNet ® 2.0 LLIN met the criteria of effective bio-efficacy up to 24 months after distribution. In Paper II, we observed low LLIN ownership and use during the study period. After 110 weeks, only 8% of households owned at least one LLIN. The median proportion of LLIN use per individuals was only 14%. More frequent LLIN use was reported by older age groups, compared with children under five years old. Similarly, people residing in houses whose heads of household had better educations reported more frequent LLIN use, compared with those with higher rates of illiteracy. Having a family size of more than five persons was associated with less frequent use of LLINs, compared with smaller family sizes. In Paper III, we observed spatial, temporal and spatiotemporal clustering of malaria infections in the study area and period. The spatial clustering of malaria at the household level was detected in all study arms (LLIN + IRS, LLIN alone, IRS alone and routine arms) with no significant difference in the risk of clustering between the arms. The risk of malaria clustering was high among households located closer to potential vector breeding sites. Moreover, an overlap was observed between clusters with low rates of LLIN use and clusters with high rates of malaria infection. The risk of malaria infection among people living in clusters with low LLIN use was 2.20 times higher than for people living in areas outside of these clusters (adjusted hazard ratio = 2.20, 95% confidence interval (CI): 1.80–2.60). Conclusion: The bed nets given for malaria prevention did not last long and were utilized as expected under field conditions in southern-central Ethiopia. Therefore, strategies are needed to address these problems and maximize malaria control efforts. We demonstrated variations in the risk of malaria infection across micro-geographic areas. None of the malaria control interventions (LLIN alone, IRS alone or combined LLIN and IRS) affected the occurrence of spatial clustering of malaria. The risk of malaria clustering was high in areas nearer to potential malaria vector breeding sites and thus prioritizing malaria control intervention in these locations could optimize resources. However, locations with low rates of LLIN use also exhibited high rates of malaria infection. Reducing variations in LLIN use in different locations thus also could reduce the risk of infection. Trial registration: PACTR 201411000882128 (8 September 2014)Doktorgradsavhandlin

Developing Marketing Capabilities Using Networks: Structure, Content, and Performance Implications

Building on marketing capabilities literature and social network theories, this thesis empirically investigates the contribution of network connections to the development of firm marketing capabilities. This thesis conceptualizes network relationships based on the cohesion and diversity of network resources in the firm-firm network and firm-government network. Using a survey and archival data obtained from 186 firms operating in the Ethiopian Commodity Exchange, this study reveals how external network partners contribute to developing firms' marketing capabilities. I found that diversity in firm–firm and firm–government networks produced comparable results, but cohesion in these two networks produce different results. The findings indicated that diversity in both firm-firm and firm-government networks contributed to marketing capabilities. While cohesion in firm-firm networks contributes to marketing capabilities, the same is not true for firm-government network cohesion and marketing capabilities relationship. Besides, the effect of network connections on marketing capabilities is contingent upon environmental dynamism and knowledge tacitness. Cohesive networks contribute to the development of marketing capabilities under a high level of knowledge tacitness. Diverse networks provide knowledge relevant to building marketing capabilities in dynamic environments. The findings also revealed that marketing capabilities mediate the effect of the firm–firm network on sales growth and new market development. This research provides new insights for marketing researchers and managers on how to make the most out of their network connections to develop marketing capabilities and how investments in developing marketing capabilities contribute to firm performance.publishedVersio

Tourism in Kenya: A preliminary examination

This study seeks to explore the trends in international tourist arrivals in a developing country - Kenya - which has been well recognized as an international tourist destination in Sub-Saharan Africa. Kenya’s tourism sector has undergone several challenges over the years. Several factors that affect the tourists’ propensity to stay longer in a destination are discussed and suggestions for marketing are proposed

Conflict Management and Resolution Strategies between Teachers and School Leaders in Primary Schools of Wolaita Zone, Ethiopia

The purpose of this study was to investigate various strategies used to manage and resolve conflict between teachers and school leaders in government primary schools of Wolaita zone. The study employed a descriptive survey design where both quantitative and qualitative approaches were used to correct and analyze data, concurrently. From six districts, ten schools were selected using both simple random and purposive sampling so as to include schools sponsored by Wolaita Development Association.  Subjects for this study included 146 teachers and 50 department heads who were randomly selected to respond to the questionnaires. Participants for interview included 10 principals, 10 vice-principals, and 20 unit leaders and 30 parent and teachers association members. Data were analyzed using descriptive statistics (frequency, percentages, means and standard deviations), and inferential statistics (t-test) using SPSS software version 20. Findings indicated that major causes of conflict were either; institutional, work or leadership related. Major conflict management strategies included; building leadership skills, following rules and regulations. embracing change, wise allocation of recourses, involvement in decision making, providing opportunities for training, and understanding individual differences and roles, In case of disputes, techniques included; discussions, punishing, forcing, compromising, avoidance, and ignorance. This study concluded that school leaders need to understand the sources of conflicts and have a mechanism in place for staff to voice their concerns. Additionally, leaders need to continuously build leadership competences, be open to change, involve and provide staff with opportunities for growth. Besides, schools leaders should look for ways to acquire and expand funding sources. Keywords: Conflicts, Management, Resolution, Teachers, Leaders, Primary Schools, Ethiopi

Unemployment experiences of young graduates and their attitudes towards Business startups in micro and small enterprises (MSEs) : a lesson from southern Ethiopia

This study is about the unemployment experiences of unemployed young graduates and their attitudes towards business startups in micro and small enterprises (MSEs) in Wolaita Sodo town, Southern Ethiopia. More specifically, it seeks to examine the job search experiences of unemployed young graduates, examine their unemployment experiences, identify the barriers and opportunities for business startups in MSEs and explore their attitudes towards business startups in MSEs. To address their job search experiences, concepts from school to work transition and human capital theory were used with other empirical examples. To address their unemployment experiences, this research used the human capital theory and the social exclusion concept. Important concepts such as youth and hope in the contemporary era, unemployment and entrepreneurship nexus, Entrepreneurship through MSEs, the role of formal education in MSE development and, supportive environment for job creation and other empirical examples are used to identify the barriers and opportunities for business startups in MSEs and to examine the attitudes of unemployed young graduates towards business startups in MSEs. Generally, the knowledge obtained from these issues together with the empirical examples were used as an interpretative base for this study. This study employed the qualitative methodology and phenomenological approach, and four primary data collection tools, namely, semi-structured interviews, focus group discussion (FGD), elite interviews, as well as direct observation and secondary data sources. Semi-structured interviews and focus group discussions were used to obtain young graduates’ unemployment experiences and their attitudes towards business startups in MSEs. Moreover, elite interviews were conducted to gather relevant data to this thesis from experts coordinating MSEs and youth affairs in Sodo town. Direct observation was conducted to gain insight into the ways young graduates are looking for vacancies and the general status of MSEs in the study area. Research participants were recruited by using snowball and purposive sampling techniques. From the findings of this study it is revealed that job search period is full of uncertainty for many and the school to work transition is not easy for most of the young graduates. The thesis found that unemployment experiences of young graduates varies depending on their gender, marital status, and level of education. The study indicated that prolonged unemployment among graduates leads to social exclusion rather than inclusion and wastes the knowledge acquired through a formal education. Besides, the study also examined unemployed young graduate’s attitudes towards business startups in MSEs. The outcomes indicate that positive images towards MSEs are mostly hindered by a lack of institutional support, lack of training and mentoring, lack of infrastructure, lack of recognizable role models and lack of inspiration from the society. Finally, the recommendations that are supposed to be helpful in order to augment the involvement of young graduates towards business startups in MSEs were provided

Examining the mediating effects of study outcomes on student experience and satisfaction

Global demand for higher education has been growing. Insight into study outcomes may hold the key to finding out what exactly students hope to take away from their university experience and how they may be satisfied. This paper's aim is to understand the mediating effects study outcomes have on student experience and satisfaction. Findings suggest study outcomes such as personal development and career opportunity mediate the relationships between student experience (image, teaching, learning, student services and technology) and student satisfaction