INTRODUCTIONEsophageal dissection is generally safe and easy during transhiatal esophagectomy (THE). The right subclavian artery crosses between the esophagus and spine in about 1 % to 2 % of cases. ...This condition is called aberrant right subclavian artery and is the most common congenital aortic arch anomaly. Pre-operative recognition of this anomaly is important in esophageal surgeries. In unprepared situations injury to this vessel may result in life threatening bleeding. CASE PRESENTATIONA 45 year old female patient presented with progressive dysphagia and weight loss. Esophageal mass was found during upper gastrointestinal endoscopy. Additionally, a CT scan of the thorax and abdomen revealed an aberrant right subclavian artery and a distal esophageal mass. Biopsy revealed squamous cell carcinoma. A transhiatal esophagectomy was performed successfully with no complications. DISCUSSIONThe vast majority of patients with an aberrant right subclavian artery do not experience any symptoms. In rare cases, patients may present with dysphagia (dysphagia lusoria) and obstructive respiratory symptoms in their fourth or fifth decade. When patients present with dysphagia from esophageal cancer, careful review of imaging is needed to identify the aberrant artery. CONCLUSIONThe presence of aberrant right subclavian artery causes difficulty in performing esophagectomy. If it is diagnosed preoperatively, cautious retroesophageal dissection prevents injury to this vessel and complications following it.
Biodiesel is a promising alternative fuel because of its renewable status, biodegradability, non-toxicity, and low pollution levels. However, other limitations such as high viscosity, low thermal ...energy content, poor atomization, greater densities, and higher (NOx) exhaust emissions hinder its adoption as a prospective diesel alternative. The current study focuses on comparing and analyzing the performance and emission effects of introducing single and hybrid cerium oxide (CeO2) and aluminum oxide (Al2O3) nanoparticles to a fuel blend of 20 % castor biodiesel and 80 % diesel (CB20) made from castor seed oil. The pulsed plasma in liquid technique, a straightforward one-step procedure, was used to create cerium oxide (CeO2) nanoparticles. When Al2O3 nanoparticles were added to the CB20, the cylinder pressure and rate of heat release increased. Therefore, in this study single and hybrid cerium oxide (CeO2) and aluminum oxide (Al2O3) nanoparticles are introduced. The tests were conducted on a single cylinder compression ignition engine at varied engine speeds between 1250 and 3200 rpm while keeping a constant engine load. Using a water bath and sonication, two concentrations of the nanoparticles—80 and 100 ppm—were introduced to the fuel blends, along with Tween 80 and span 80 surfactants to improve blend stability. Different tested fuel samples, including pure diesel CB0, CB20, CB20C100, CB20C80, CB20A100, CB20A80, CB20A40C40, and CB20A50C50, were examined for their physiochemical properties, such as density, viscosity, cloud point, pour point, flash point, and fire points, as well as engine performance parameters, including torque, power, fuel consumption, BTE, and EGT. CB20A50C50 and CB20A40C40 both had an average brake power that was higher than diesel fuel by 6.14 % and 1.25 percent, respectively. The average brake-specific fuel consumption decreased by 3.21 % to 8.29 % when using hybrid and single nano-additive blended fuels compared to CB20. CB20A50C50 exhibited a 20.38 % higher brake thermal efficiency than CB20. Notably, CB20C100 showed a 29.52 % reduction in HC and a 38.32 % reduction in CO, while CB20A50C50 demonstrated a 10.24 % decrease in NOx compared to CB20. Overall, the results of this study indicate that the generated fuel blends combining castor biodiesel and aluminum oxide/cerium oxide nanoparticles hold promise as alternate fuels for diesel engines, with positive impacts on engine performance and emissions.
•Macrophyte dynamics related to physico-chemical factors in the largest Ethiopian lake.•30 species belonging to 15 families identified in this freshwater high altitude lake.•Emergent and amphibious ...macrophytes dominated, both groups tolerant towards turbidity.•Changes in trophic state are leading to a dynamic change in macrophyte diversity.
Between October 2014 to September 2016 we investigated the distribution of macrophyte assemblages in relation to water quality in the south western littoral zone of Lake Tana. in situ measurements of physicochemical parameters (DO, pH, EC, TDS, temperature and Secchi depth) were accompanied by nutrient analyses for NO3-N, soluble reactive phosphate (SRP) and total phosphorus (TP). Macrophytes were collected manually using a belt transect method. Thirty macrophyte species belonging to fifteen families were identified. Emergent and amphibious plants had the maximum percentage composition at 53 % and 30 %, respectively and attained the highest relative frequency and density, followed by floating species and other forms. Redundancy analysis (RDA) indicated that the density of Azolla pinnata subsp. africana, Ceratophyllum demersum, Cyperus alopecuroides, Digitaria milanjiana, Pycreus macrostachyos, Pycnostachys coerulea and Scirpus pallidus was positively and strongly associated with pH, Secchi depth, SRP and TP whereas that of Amaranthus hypochondriacus, Cyperus papyrus, Echinochloa stagnina, Ipomoea aquatic, Panicum maximum, Sacciolepis Africana and Stuckenia pectinata was negatively and strongly associated with these variables but positively with NO3-N. The density of Brachiaria sp., Vossia cuspidate and Leersia hexandra was negatively and strongly associated with pH, SRP and TP whereas the density of Typha latifolia was positively and strongly associated with TDS and EC. The highest diversity index (H′ = 2.63) was recorded in Zegie Yiganda sampling site, which was better protected from anthropogenic impacts. In conclusion, Lake Tana is experiencing changes in physico-chemical parameters, which has favored a shift in species composition of macrophytes towards turbidity-tolerant emergent and amphibious species.
Organic matter and some selected metals (As, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Pb, and Zn) were measured from water and sediment while plant samples from the inlet to the outlet sampling sites using ...standard procedures from three compartments (water, sediment, and macrophytes) of Yitamot wetland. Findings indicated that the mean concentration of COD in water was in the range of 5.25 mg/L and 208.25 mg/L and showed a significant and exponential decrease along the subsequent sampling sites (P<0.05). The mean concentrations of K, As, Cd, and Cr (82.192 mg/kg, 0.730 mg/kg, 0.06 mg/kg, and 19.776 mg/kg, respectively) were significantly lower values in the outlet than in the inlet of the sediment samples (P<0.05). All the metal concentrations in the aboveground tissue of macrophytes were significantly lower at the outlet sample site (P<0.05) indicating that these compartments are contributing to the retention of metals and organic matter present in wastewater discharged in the wetland through sinks and conversions of these compounds. However, there was no significant removal effect for heavy metals like Fe, Zn, and As (P>0.05). This is a pointer to the fact that natural wetlands can be used effectively for wastewater treatment with strong monitoring programs and ecological indicators for the sustainable management and conservation of the flora and fauna present in it.
This paper explored how the need for research universities in Ethiopia is justified, practiced, and could be improved using the strategic tactics of the resource dependency perspective. Bahir Dar ...University (hereafter referred to as BDU) was taken as a case to understand the need for a research university and its practices. Document analysis was used as a source of data. Consequently, an analysis of various institutional and national secondary sources revealed that the existing uncertainties related to critical resources motivated Bahir Dar University to devise a strategic choice of becoming a research university. The uncertainties are justified in terms of economic, political and institutional conditions. Although the university envisioned becoming a research university by 2025, the existing institutional and national conditions seem to be immature to sustain the necessary resources and conditions that a research university requires. As a result, following the higher education differentiation effort, BDU had to revise its vision and extend the possible time its vision could be realized to 2030. It is concluded that the need for BDU to become a research university seems to be challenging and needs much effort to be realized. Hence, institutional re-arrangements following the strategic tactics of the resource dependency perspective need to be devised to realize the strategic choice of becoming a research university.
Grazing exclosures have been promoted as an effective and low-cost land management strategy to recover vegetation and associated functions in degraded landscapes in the tropics. While grazing ...exclosures can be important reservoirs of biodiversity and carbon, their potential in playing a dual role of conservation of biodiversity and mitigation of climate change effects is not yet established. To address this gap, we assessed the effect of diversity on aboveground carbon (AGC) and the relative importance of the driving biotic (functional diversity, functional composition and structural diversity) and abiotic (climate, topography and soil) mechanisms. We used a dataset from 133 inventory plots across three altitudinal zones, i.e., highland, midland and lowland, in northern Ethiopia, which allowed local- (within altitudinal zone) and broad- (across altitudinal zones) environmental scale analysis of diversity-AGC relationships. We found that species richness-AGC relationship shifted from neutral in highlands to positive in mid- and lowlands as well as across the altitudinal zones. Structural diversity was consistently the strongest mediator of the positive effects of species richness on AGC within and across altitudinal zones, whereas functional composition linked species richness to AGC at the broad environmental scale only. Abiotic factors had direct and indirect effects via biotic factors on AGC, but their relative importance varied with altitudinal zones. Our results indicate that the effect of species diversity on AGC was altitude-dependent and operated more strongly through structural diversity (representing niche complementarity effect) than functional composition (representing selection effect). Our study suggests that maintaining high structural diversity and managing functionally important species while promoting favourable climatic and soil conditions can enhance carbon storage in grazing exclosures.
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•Carbon storage increases with species richness only in mid- and lowlands.•Structural diversity, expressed as variances in tree size, consistently mediated the positive effects of diversity on AGC.•Tree species diversity and their structural complexity should be promoted to enhance C storage.
Antimicrobial resistance is one of the major public health challenges in Ethiopia. However, there is no comprehensive summary of existing AMR data in the country.
To determine the prevalence of ...antimicrobial resistance and its clinical implications in Ethiopia.
A systematic literature search was performed on the PubMed/Medline database. Original studies on antimicrobial resistance conducted in Ethiopia between 1st January 2009 and 31st July 2019 were included. The outcome measure was the number of isolates resistant to antimicrobial agents in terms of specific pathogens, and disease condition. Data was calculated as total number of resistant isolates relative to the total number of isolates per specific pathogen and medication.
A total of 48,021 study participants enrolled from 131 original studies were included resulting in 15,845 isolates tested for antimicrobial resistance. The most common clinical sample sources were urine (28%), ear, nose, and throat discharge collectively (27%), and blood (21%). All the studies were cross-sectional and 83% were conducted in hospital settings. Among Gram-positive bacteria, the reported level of resistance to vancomycin ranged from 8% (Enterococcus species) to 20% (S. aureus). E. coli, K. pneumoniae and P. aeruginosa were the most common Gram-negative pathogens resistant to key antimicrobial agents described in the national standard treatment guideline and were associated with diverse clinical conditions: urinary tract infections, diarrhea, surgical site infections, pneumonia, ocular infections, and middle ear infections.
Overall, there is a high prevalence of antimicrobial resistance in Ethiopia. Empirical treatment of bacterial infections needs to be guided by up-to-date national guidelines considering local antimicrobial susceptibility patterns. Equipping diagnostic laboratories with culture and drug susceptibility testing facilities, and establishing a strong antimicrobial stewardship program should be high priorities.
Abstract
Background
The COVID-19 pandemic has been linked to chronic pulmonary complications all over the world. Respiratory complications such as chronic cough, dyspnea, increased respiratory rate, ...and oxygen support demand are prevalent in recovered COVID-19 patients. These problems are long-term and have a negative impact on one’s quality of life. Patients must be evaluated for potential complications, and risk factors must be found. Some reports around the world explain the factors that contribute to the development of these complications. However, to the best of our understanding, no reports of post-COVID-19 complications have been reported from Ethiopia.
Methods
Facility based cross-sectional study was done among 405 participants selected by simple random sampling technique. Structured questionnaire which includes participants’ demographic, clinical and 3rd month visit characteristics was collected by Open Data Kit and exported to SPSS version 25.0 for analysis. Percentage with frequency and median with Interquartile range was used in descriptive statistics. The association between variables was analyzed with bivariate and multi variable logistic regression. A statistical significance was declared at p-value < 0.05, with 95% confidence interval.
Results
The median (Interquartile range) age of participants was 57.0 (43.0, 65.0) years, 63.2% were males. The prevalence of post-COVID-19 pulmonary complication in recovered COVID-19 patients was 14.1% (95% CI: 10.8%, 17.8%). After adjusting for possible confounders on multivariate analysis, older age AOR = 0.227, 95% CI (0.08–0.66) and consolidation AOR = 0.497, 95% CI (0.258–0.957) were shown to have significant association with post COVID-19 pulmonary complications.
Conclusion
The prevalence of post COVID-19 pulmonary complication was observed to be lower than other reports globally. Older age and the presence of consolidation on lung imaging were associated with those complications. Clinicians are recommended to consider assessing the lasting effects of the pandemic, beyond immediate care, and should also investigate the COVID-19 history in patients presenting with respiratory issues.
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