This study evaluated the effects of solar UV-B (Ultraviolet-B) radiation on coffee seedlings at different altitudinal ranges in a tropical environment. A field experiment, conducted using a randomized complete block design, tested four coffee varieties—Fayette, Odisha, Koti, and Hangafa—under natural UV-B radiation and UV-B-blocking sheets at altitudes of 1450, 1850, and 2150 m, with three replications. The results revealed that altitude significantly influenced most growth parameters, except for specific leaf area and primary branch girth. The interaction between altitude and coffee variety affected plant height, primary branch length, and internode length (at p < 0.001, 0.01 and 0.05, respectively), with plant height and primary branch length decreasing as altitude increased. Altitude also impacted leaf area and physiological parameters such as photosynthetic rate (Pn) and transpiration rate. In contrast, the interaction of UV-B and altitude influenced stomatal conductance and intercellular CO2 levels. These findings demonstrate that coffee varieties respond differently to solar UV-B radiation at different altitudes. This highlights the need for location-specific coffee breeding/genetic selection/ in tropical environments to address adaptation to climate change, particularly in relation to increased UV radiation.
Ecological and infection predator prey mathematical model is important tool for understanding complex systems and forecasting outcomes biologically. Incorporating saturation mass action incidence rates representing the rate of susceptible prey infection as a function of time along with time delay terms, makes more realistic and reflective of the inherent dynamics in the real-world systems. This study develops and analyzes delayed ecology model with disease where prey is infected by microparasites, and the predator consume both susceptible and diseased prey. The infection process is assumed to involve a constant time delay, referred to as the infection delay, while the predator reproduction following prey consumption introduces another delay, known as the gestation delay. Qualitative analysis of the model is verified. The consequence of delay terms in the model on the stability of the coexistence fixed point is investigated by treating the delay as a bifurcation parameter. The results indicate the existence of Hopf bifurcation and stability switching as delay cross a certain critical threshold values. Finally, we performed numerical simulations using ODE 45 and DDE 23 codes to support the theoretical and qualitative results in agreement with numerical findings.
Although school ethical leadership plays a crucial role in individual and organizational behaviors, the impact of school principals' ethical leadership on teachers' organizational commitment has not received as much research attention. The main purpose of this study was to examine the influence of school principals' ethical leadership on teachers' organizational commitment in government secondary schools in Sidama National Regional State, Ethiopia. To achieve this purpose, a correlational study design was employed. A multistage sampling technique was utilized to draw representative samples from the target population. Through this process, one zone and one City Administration were chosen. Subsequently, six secondary schools and 259 teachers were selected as the study sample. Data were collected using a questionnaire, and the validity and reliability of the instruments were thoroughly checked. Descriptive and inferential statistical analyses were applied for data analysis. The study result showed a positive, strong, and significant relationship between school principals' ethical leadership and teachers' organizational commitment. The study further revealed that ethical leadership dimensions were positively and significantly related to teachers' organizational commitment. Moreover, all dimensions of ethical leadership, except for the behavioral ethical leadership dimension, had a positive, statistically significant, and moderate effect on teachers' organizational commitment. The study implies that school principals should actively exhibit and reinforce ethical behaviors in their activities, as an empirically supported factor in enhancing teachers' organizational commitment. Education offices should also establish ethical guidelines and capacity-building initiatives to ensure that all school leaders consistently demonstrate ethical leadership.
Camelina (Camelina sativa (L.) Crantz), an ancient oilseed crop with biofuel and nutritional value, suffers from low productivity in Ethiopia due to limited improved varieties, underdeveloped seed systems, and suboptimal fertilizer application. This study investigated the effects of cultivar, seed rate, and nitrogen-phosphorus-sulfur-boron (NPSB) fertilizer on camelina growth, agronomic performance, and yield to address this constraint. Field experiments were conducted in the cool sub-humid highlands of the Hadiya Zone (Lemo and Misha districts) during the 2023 and 2024 cropping seasons. A split-split plot design evaluated two cultivars (Zeytee-1 and Syria), three seed rates (5, 7.5, and 10 kg ha- 1), and four NPSB fertilizer rates (0, 50, 100, and 150 kg ha- 1). Data on soil properties, crop growth, and yield components were collected and analyzed using Statistical Analysis System. Results demonstrated that NPSB fertilization at 100 and 150 kg ha- 1 significantly enhanced dry matter accumulation, branching, and silique production. The Syria cultivar outperformed Zeytee-1, achieving peak grain yields of 2.53 and 2.54 t ha- 1 with 100 and 150 kg NPSB ha- 1 at the respective sites. A seed rate of 7.5 kg ha- 1 optimized silique production (89 per plant for Syria), while 10 kg ha- 1 maximized grain yield under high fertilization. Grain yield exhibited a strong positive correlation with siliques per plant (r = 0.979), dry matter (r = 0.846), and leaf area index (r = 0.842). For optimal productivity in Hadiya's agroecology, this study recommends integrating the Syria cultivar with 100 kg NPSB ha- 1 and a seed rate of 7.5-10 kg ha- 1.
Abstract Purpose This study examines the influence of key service quality dimensions physical environment, “care responsiveness, and patient-centered care on patient loyalty, and investigates the mediating role of patient satisfaction in public hospitals in Sidama Regional State, Ethiopia. The region was selected as a representative setting of public healthcare delivery in resource-constrained environments, where service quality challenges are particularly evident. Design/methodology/approach A facility-based cross-sectional design was employed using data collected from 382 patients attending public hospitals in Sidama Regional State. The sample size was justified using an a priori statistical power analysis suitable for structural equation modeling, ensuring adequate power to detect medium effect sizes. Respondents were selected through convenience sampling. Data were collected using a structured questionnaire adapted from validated scales. The study applied Partial Least Squares Structural Equation Modeling (PLS-SEM) using SmartPLS to test both direct and mediating relationships. Reliability and validity were assessed through Cronbach’s alpha, composite reliability, average variance extracted (AVE), and discriminant validity criteria. Findings The results show that physical environment (β = 0.211, p < 0.001) and care responsiveness (β = 0.479, p < 0.001) have significant positive effects on patient loyalty. Similarly, physical environment (β = 0.457, p < 0.001) and care responsiveness (β = 0.288, p < 0.001) significantly influence patient satisfaction. Patient-centered care has a significant direct effect on loyalty (β = 0.225, p < 0.001) but an insignificant effect on satisfaction (β = 0.077, p > 0.05). Patient satisfaction significantly predicts patient loyalty (β = 0.112, p < 0.05) and partially mediates the relationship between service quality and loyalty. The model explains a substantial proportion of variance in patient loyalty (R2 = 0.802) and satisfaction (R2 = 0.548), with care responsiveness emerging as the strongest predictor. Originality/value This study contributes to the literature by addressing both theoretical and methodological gaps. Theoretically, it integrates Expectation–Confirmation Theory and Social Exchange Theory to explain the cognitive and relational mechanisms linking service quality to loyalty. Methodologically, it applies a PLS-SEM mediation model in a public healthcare context, which remains underexplored in Sub-Saharan Africa. Empirically, it provides context-specific evidence from Ethiopian public hospitals, offering practical insights for improving service quality and strengthening patient-centered healthcare delivery in resource-constrained settings.
