Search results for: Tsegay Giday Woldu
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 12

Search results for: Tsegay Giday Woldu

12 A Modified Nonlinear Conjugate Gradient Algorithm for Large Scale Unconstrained Optimization Problems

Authors: Tsegay Giday Woldu, Haibin Zhang, Xin Zhang, Yemane Hailu Fissuh

Abstract:

It is well known that nonlinear conjugate gradient method is one of the widely used first order methods to solve large scale unconstrained smooth optimization problems. Because of the low memory requirement, attractive theoretical features, practical computational efficiency and nice convergence properties, nonlinear conjugate gradient methods have a special role for solving large scale unconstrained optimization problems. Large scale optimization problems are with important applications in practical and scientific world. However, nonlinear conjugate gradient methods have restricted information about the curvature of the objective function and they are likely less efficient and robust compared to some second order algorithms. To overcome these drawbacks, the new modified nonlinear conjugate gradient method is presented. The noticeable features of our work are that the new search direction possesses the sufficient descent property independent of any line search and it belongs to a trust region. Under mild assumptions and standard Wolfe line search technique, the global convergence property of the proposed algorithm is established. Furthermore, to test the practical computational performance of our new algorithm, numerical experiments are provided and implemented on the set of some large dimensional unconstrained problems. The numerical results show that the proposed algorithm is an efficient and robust compared with other similar algorithms.

Keywords: conjugate gradient method, global convergence, large scale optimization, sufficient descent property

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11 Induction and Mentorship of Junior Faculty Members: A Managerial Challenge in the Institutions of Higher Education in Eritrea

Authors: Zecarias Zemichael Woldu

Abstract:

Cultivation of professionalism and dispositional values in junior faculty members in institutions of higher education (IHE) is a global challenge. Junior faculty members complain of the managerial inefficiency and lack of modeling in their career development. This paper explored how Graduate Teaching Assistants (GTAs) are inducted into the system and mentored at work in the IHE in Eritrea. It assesses the institutional significance and challenges of mentoring junior faculty members in IHE. The research was conducted in 7 IHE involving 165 participants. Quantitative and qualitative data were gathered through Likert scale questionnaire and in-depth interviews. A One-Way ANOVA was used to assess the GTAs’ knowledge of assigned duties and responsibilities, access to institutional information and resources, the quality of guidance and support provided and above all the mentoring state of affairs across the colleges. Results revealed that junior faculty shoulder vital responsibilities but they receive poor induction and mentoring at individual and institutional levels. A large number of junior faculty members revealed a need of serious professional molding to effectively shoulder more responsibilities in the colleges.

Keywords: induction, mentoring, junior faculty members, Eritrea

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10 Servant Leadership and Organizational Citizenship Behavior: The Mediating Role of Perceived Organizational Politics and the Moderating Role of Political Skill in Public Service Organizations

Authors: Debalkie Demissie Addisu, Ejigu Alemu Abebe, Tsegay Tensay Assefa

Abstract:

This study examines the indirect effect of servant leadership on organizational citizenship behavior through perceptions of organizational politics moderated by political skill. This study reports the responses of 321 respondents from six federal public service organizations in Ethiopia. A multi-stage random sampling procedure was employed to select the sampled federal public service organizations. To test hypotheses, the study employed structural equation modeling using AMOS version-26 software. The result revealed that all direct effects have a significant effect. Specifically, servant leadership has a positive effect on organizational citizenship behavior. Likewise, servant leadership has a negative effect on perceptions of organizational politics. Also, a perception of organizational politics has a negative effect on organizational citizenship behavior. Moreover, perceptions of organizational politics competitively mediated the effect of servant leadership on organizational citizenship behavior. As well, political skill moderated the effect of perceptions of organizational politics on organizational citizenship behavior but not the indirect effect. To the best of our knowledge, no one else employs perceptions of organizational politics as a mediating effect between servant leadership and organizational citizenship behavior. Furthermore, we are not aware of anyone else employing political skill as a moderating role in the indirect effect of servant leadership on organizational citizenship behavior through perceptions of organizational politics.

Keywords: servant leadership, organizational citizenship behavior, perceptions of organizational politics, political skill, public service organization, Ethiopia

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9 Seroprevalence and Associated Factors of Hepatitis B and Hepatitis C Viral Infections Among Prisoners in Tigray, Northern Ethiopia

Authors: Belaynesh Tsegay, Teklay Gebrecherkos, Atsebaha Gebrekidan Kahsay, Mahmud Abdulkader

Abstract:

Background: Hepatitis B and C viruses are important health and socioeconomic problem across the globe, with a remarkable number of diseases and deaths in sub-Saharan African countries. The burden of hepatitis is unknown in the prison settings of Tigray. Therefore, we aimed to describe the seroprevalence and associated factors of hepatitis B and C viruses among prisoners in Tigray, Ethiopia. Methods: A cross-sectional study was carried out from February 2020 to May 2020 at the prison facilities of Tigray. Demographics and associated factors were collected from 315 prisoners prospectively. Five milliliters of blood were collected and tested using rapid tests kits of HBsAg (Zhejiang orient Gene Biotech Co., Ltd., China) and HCV antibodies (Volkan Kozmetik Sanayi Ve Ticaret Ltd. STI, Turkey). Positive samples were confirmed using ELISA (Beijing Wantai Biological Pharmacy Enterprise Co. Ltd). Data were analyzed using the SPSS version 20, and p<0.05 was considered statistically significant. Results: The overall seroprevalence of HBV and HCV were 25 (7.9%) and 1 (0.3%), respectively. The majority of hepatitis B viral infections were identified from the age groups of 18–25 years (10.7%) and unmarried prisoners (11.8%). Prisoners greater than 100 per cell (AOR=3.95, 95% CI=1.15–13.6, p=0.029) and with a history of alcohol consumption (AOR=3.01, 95% CI=1.17–7.74, p=0.022) were significantly associated with HBV infections. Conclusion: The seroprevalence of HBV among prisoners was nearly high or borderline, with a very low HCV prevalence. HBV was most prevalent among young adults, those housed with a large number of prisoners per cell, and those who had a history of alcohol consumption. This study recommends that there should be prison-focused intervention, including regular health education, with the emphasis on the mode of transmission and introducing HBV screening policy for prisoners, especially when they enter the prison.

Keywords: seroprevalence, HBV, HCV, prisoners, tigray

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8 Development and Validation of Integrated Continuous Improvement Framework for Competitiveness: Mixed Research of Ethiopian Manufacturing Industries

Authors: Haftu Hailu Berhe, Hailekiros Sibhato Gebremichael, Kinfe Tsegay Beyene, Haileselassie Mehari

Abstract:

The purpose of the study is to develop and validate integrated literature-based JIT, TQM, TPM, SCM and LSS framework through a combination of the PDCA cycle and DMAIC methodology. The study adopted a mixed research approach. Accordingly, the qualitative study employed to develop the framework is based on identifying the uniqueness and common practices of JIT, TQM, TPM, SCM and LSS initiatives, the existing practice of the integration, identifying the existing gaps in the framework and practices, developing new integrated JIT, TQM, TPM, SCM and LSS practice framework. Previous very few studies of the uniqueness and common practices of the five initiatives are preserved. Whereas the quantitative study working to validate the framework is based on empirical analysis of the self-administered questionnaire using a statistical package for social science. A combination of the PDCA cycle and DMAIC methodology stand integrated CI framework is developed. The proposed framework is constructed as a project-based framework with five detailed implementation phases. Besides, the empirical analysis demonstrated that the proposed framework is valuable if adopted and implemented correctly. So far, there is no study proposed & validated the integrated CI framework within the scope of the study. Therefore, this is the earliest study that proposed and validated the framework for manufacturing industries. The proposed framework is applicable to manufacturing industries and can assist in achieving competitive advantages when the manufacturing industries, institutions and government offer unconditional efforts in implementing the full contents of the framework.

Keywords: integrated continuous improvement framework, just in time, total quality management, total productive maintenance, supply chain management, lean six sigma

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7 Sulfur-Containing Diet Shift Hydrogen Metabolism and Reduce Methane Emission and Modulated Gut Microbiome in Goats

Authors: Tsegay Teklebrhan Gebremariam, Zhiliang, Arjan Jonker

Abstract:

The study investigated that using corn gluten (CG) instead of cornmeal (CM) increased dietary sulfur shifted H₂ metabolism from methanogenesis to alternative sink and modulated microbiome in the rumen as well as hindgut segments of goats. Ruminal fermentation, CH₄ emissions and microbial abundance in goats (n = 24). The experiment was performed using a randomized block design with two dietary treatments (CM and CG with 400 g/kg DM each). Goats in CG increased sulfur, NDF and CP intake and decreased starch intake as compared with those in CM. Goats that received CG diet had decreased dissolved hydrogen (dH₂) (P = 0.01) and dissolved methane yield and emission (dCH₄) (P = 0.001), while increased dH₂S both in the rumen and hindgut segments than those fed CM. Goats fed CG had higher (p < 0.01) gene copies of microbiota and cellulolytic bacteria, whereas starch utilizing bacterial species were less in the rumen and hindgut than those fed CM. Higher (P < 0.05) methanogenic diversity and abundances of Methanimicrococcus and Methanomicrobium were observed in goats that consumed CG, whilst containing lower Methanobrevibacter populations than those receiving CM. The study suggested that goats fed corn gluten improved the gene copies of microbiota and fibrolytic bacterial species while reducing starch utilizing species in the rumen and hindgut segments as compared with that fed cornmeal. Goats consuming corn gluten had a more enriched methanogenic diversity and reduced Methanobrevibacter, a contributor to CH₄ emissions, as compared with goats fed CM. Corn gluten could be used as an alternative feed to decrease the enteric CH₄ emission in ruminant production.

Keywords: dissolved gasses, methanogenesis, microbial community, metagenomics

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6 Seroprevalence and Associated Factors of Hepatitis B and Hepatitis C Viral Infections among Prisoners in Tigrai, Northern Ethiopia

Authors: Belaynesh Tsegay Beyene, Teklay Gebrecherkos, Atsebaha Gebrekidan Kahsay, Mahmud Abdulkader

Abstract:

Background: Hepatitis B and C viruses are of important health and socioeconomic problem of the globe with remarkable diseases and deaths in Sub-Saharan African countries. The burden of hepatitis is unknown in the prison settings of Tigrai. Therefore, we aimed to describe the seroprevalence and associated factors of hepatitis B and C viruses among prisoners of Tigrai, Ethiopia. Methods: A cross-sectional study was carried out from February 2020 to May 2020 at the prison facilities of Tigrai. Demographics and associated factors were collected from 315 prisoners prospectively. Five milliliter of blood was collected and tested using rapid tests kits of HBsAg (Zhejiang orient Gene Biotech Co., Ltd., China) and HCV antibodies (Volkan Kozmetik Sanayi Ve Ticaret Ltd. STI, Turkey). Positive samples were confirmed using enzyme-linked immunosorbent assay (ELISA) (Beijing Wantai Biological Pharmacy Enterprise Co. Ltd). Data were analyzed using Statistical Package for Social Sciences (SPSS) version 20 and p < 0.05 was considered statistically significant. Results: The overall seroprevalence of HBV and HCV were 25 (7.9%) and 1(0.3%), respectively. The majority of hepatitis B viral infections were identified from the age groups of 18-25 years (10.7%) and unmarried prisoners (11.8%). Prisoners greater than 100 per cell [AOR =3.95, 95% CI= (1.15, 13.6, p =0.029)] and having history of alcohol consumption [AOR =3.01, 95% CI= (1.17, 7.74, p =0.022)] were significantly associated with HBV infections. Conclusions: The seroprevalence of HBV among prisoners was nearly high or borderline (7.9%) with a very low HCV prevalence (0.3%). HBV was most prevalent among young adults, large number of prisoners per cell and those who had history of alcohol consumption. This study recommends that there should be prison-focused intervention including regular health education by emphasis on the mode of transmission and introducing HBV screening policy for prisoners especially when they enter to the prison.

Keywords: seroprevalence, HBV, HCV, prisoners, Tigrai

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5 Stability Analysis of Green Coffee Export Markets of Ethiopia: Markov-Chain Analysis

Authors: Gabriel Woldu, Maria Sassi

Abstract:

Coffee performs a pivotal role in Ethiopia's GDP, revenue, employment, domestic demand, and export earnings. Ethiopia's coffee production and exports show high variability in the amount of production and export earnings. Despite being the continent's fifth-largest coffee producer, Ethiopia has not developed its ability to shine as a major exporter in the globe's green coffee exports. Ethiopian coffee exports were not stable and had high volume and earnings fluctuations. The main aim of this study was to analyze the dynamics of the export of coffee variation to different importing nations using a first-order Markov Chain model. 14 years of time-series data has been used to examine the direction and structural change in the export of coffee. A compound annual growth rate (CAGR) was used to determine the annual growth rate in the coffee export quantity, value, and per-unit price over the study period. The major export markets for Ethiopian coffee were Germany, Japan, and the USA, which were more stable, while countries such as France, Italy, Belgium, and Saudi Arabia were less stable and had low retention rates for Ethiopian coffee. The study, therefore, recommends that Ethiopia should again revitalize its market to France, Italy, Belgium, and Saudi Arabia, as these countries are the major coffee-consuming countries in the world to boost its export stake to the global coffee markets in the future. In order to further enhance export stability, the Ethiopian Government and other stakeholders in the coffee sector should have to work on reducing the volatility of coffee output and exports in order to improve production and quality efficiency, so that stabilize markets as well as to make the product attractive and price competitive in the importing countries.

Keywords: coffee, CAGR, Markov chain, direction of trade, Ethiopia

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4 The Magnitude and Associated Factors of Coagulation Abnormalities Among Liver Disease Patients at the University of Gondar Comprehensive Specialized Hospital Northwest, Ethiopia

Authors: Melkamu A., Woldu B., Sitotaw C., Seyoum M., Aynalem M.

Abstract:

Background: Liver disease is any condition that affects the liver cells and their function. It is directly linked to coagulation disorders since most coagulation factors are produced by the liver. Therefore, this study aimed to assess the magnitude and associated factors of coagulation abnormalities among liver disease patients. Methods: A cross-sectional study was conducted from August to October 2022 among 307 consecutively selected study participants at the University of Gondar Comprehensive Specialized Hospital. Sociodemographic and clinical data were collected using a structured questionnaire and data extraction sheet, respectively. About 2.7 mL of venous blood was collected and analyzed by the Genrui CA51 coagulation analyzer. Data was entered into Epi-data and exported to STATA version 14 software for analysis. The finding was described in terms of frequencies and proportions. Factors associated with coagulation abnormalities were analyzed by bivariable and multivariable logistic regression. Result: In this study, a total of 307 study participants were included. Of them, the magnitude of prolonged Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT) were 68.08% and 63.51%, respectively. The presence of anemia (AOR = 2.97, 95% CI: 1.26, 7.03), a lack of a vegetable feeding habit (AOR = 2.98, 95% CI: 1.42, 6.24), no history of blood transfusion (AOR = 3.72, 95% CI: 1.78, 7.78), and lack of physical exercise (AOR = 3.23, 95% CI: 1.60, 6.52) were significantly associated with prolonged PT. While the presence of anaemia (AOR = 3.02; 95% CI: 1.34, 6.76), lack of vegetable feeding habit (AOR = 2.64; 95% CI: 1.34, 5.20), no history of blood transfusion (AOR = 2.28; 95% CI: 1.09, 4.79), and a lack of physical exercise (AOR = 2.35; 95% CI: 1.16, 4.78) were significantly associated with abnormal APTT. Conclusion: Patients with liver disease had substantial coagulation problems. Being anemic, having a transfusion history, lack of physical activity, and lack of vegetables showed significant association with coagulopathy. Therefore, early detection and management of coagulation abnormalities in liver disease patients are critical.

Keywords: coagulation, liver disease, PT, Aptt

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3 Harnessing Clinical Trial Capacity to Mitigate Zoonotic Diseases: The Role of Expert Scientists in Ethiopia

Authors: Senait Belay Adugna, Mirutse Giday, Tsegahun Manyazewal

Abstract:

Background: The emergence and resurgence of zoonotic diseases have continued to be a major threat to global health and the economy. Developing countries are particularly vulnerable due to agricultural expansions and the domestication of animals by humans. Scientifically sound clinical trials are important to find better ways to prevent, diagnose, and treat zoonotic diseases, while there is a lack of evidence to inform the clinical trials’ capacity and practice in countries highly affected by the diseases. This study aimed to investigate researchers’ perceptions and experiences in conducting clinical trials on zoonotic diseases in Ethiopia. Methods: This study employed a descriptive, qualitative study design. It included major academic and research institutions in Ethiopia that had active engagements in veterinary and public health research. It included the National Veterinary Institute, the National Animal Health Diagnostic and Investigation Center, the College of Veterinary Medicine at Addis Ababa University, the Ethiopian Public Health Institute, the Armauer Hansen Research Institute, and the College of Health Sciences at Addis Ababa University. In-depth interviews were conducted with 14 senior researcher investigators in the institutions who hold a proven exhibit primarily leading research activities or research units. Data were collected from October 2019 to April 2020. Data analysis was undertaken using open code 4.03 for qualitative data analysis. Results: Five major themes, with 18 sub-themes, emerged from the in-depth interview in connection. These were: challenges in the prevention, control, and treatment of zoonotic diseases; One Health approach to mitigate zoonotic diseases; personal and institutional experiences in conducting clinical trials on zoonotic diseases; barriers in conducting clinical trials towards zoonotic diseases; and strategies that promote conducting clinical trials on zoonotic diseases. Conducting clinical trials on zoonotic diseases in Ethiopia is hampered by a lack of clearly articulated ethics and regulatory frameworks, trial experts, financial resources, and good governance. Conclusions: In Ethiopia, conducting clinical trials on zoonotic diseases deserves due attention. Strengthening institutional and human resources capacity is a precondition to harnessing effective implementation of clinical trials on zoonotic diseases in the country. In Ethiopia, where skilled human resource is scarce, the One Health approach has the potential to form multidisciplinary teams to systematically improve clinical trials capacity and outcomes in the country.

Keywords: Ethiopia, clinical triak, zoonoses, disease

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2 Novel p22-Monoclonal Antibody Based Blocking ELISA for the Detection of African Swine Fever Virus Antibodies in Serum

Authors: Ghebremedhin Tsegay, Weldu Tesfagaber, Yuanmao Zhu, Xijun He, Wan Wang, Zhenjiang Zhang, Encheng Sun, Jinya Zhang, Yuntao Guan, Fang Li, Renqiang Liu, Zhigao Bu, Dongming Zhao*

Abstract:

African swine fever (ASF) is a highly infectious viral disease of pigs, resulting in significant economic loss worldwide. As there is no approved vaccines and treatments, the control of ASF entirely depends on early diagnosis and culling of infected pigs. Thus, highly specific and sensitive diagnostic assays are required for accurate and early diagnosis of ASF virus (ASFV). Currently, only a few recombinant proteins have been tested and validated for use as reagents in ASF diagnostic assays. The most promising ones for ASFV antibody detection were p72, p30, p54, and pp62. So far, three ELISA kits based on these recombinant proteins have been commercialized. Due to the complex nature of the virus and variety forms of the disease, robust serodiagnostic assays are still required. ASFV p22 protein, encoded by KP177R gene, is located in the inner membrane of viral particle and appeared transiently in the plasma membrane early after virus infection. The p22 protein interacts with numerous cellular proteins, involved in processes of phagocytosis and endocytosis through different cellular pathways. However, p22 does not seem to be involved in virus replication or swine pathogenicity. In this study, E.coli expressed recombinant p22 protein was used to generate a monoclonal antibody (mAb), and its potential use for the development of blocking ELISA (bELISA) was evaluated. A total of 806 pig serum samples were tested to evaluate the bELISA. Acording the ROC (Reciever operating chracteristic) analysis, 100% sensitivity and 98.10% of specificity was recorded when the PI cut-off value was set at 47%. The novel assay was able to detect the antibodies as early as 9 days post infection. Finaly, a highly sensitive, specific and rapid novel p22-mAb based bELISA assay was developed, and optimized for detection of antibodies against genotype I and II ASFVs. It is a promising candidate for an early and acurate detection of the antibodies and is highly expected to have a valuable role in the containment and prevention of ASF.

Keywords: ASFV, blocking ELISA, diagnosis, monoclonal antibodies, sensitivity, specificity

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1 Insulin Receptor Substrate-1 (IRS1) and Transcription Factor 7-Like 2 (TCF7L2) Gene Polymorphisms Associated with Type 2 Diabetes Mellitus in Eritreans

Authors: Mengistu G. Woldu, Hani Y. Zaki, Areeg Faggad, Badreldin E. Abdalla

Abstract:

Background: Type 2 diabetes mellitus (T2DM) is a complex, degenerative, and multi-factorial disease, which is culpable for huge mortality and morbidity worldwide. Even though relatively significant numbers of studies are conducted on the genetics domain of this disease in the developed world, there is huge information gap in the sub-Saharan Africa region in general and in Eritrea in particular. Objective: The principal aim of this study was to investigate the association of common variants of the Insulin Receptor Substrate 1 (IRS1) and Transcription Factor 7-Like 2 (TCF7L2) genes with T2DM in the Eritrean population. Method: In this cross-sectional case control study 200 T2DM patients and 112 non-diabetes subjects were participated and genotyping of the IRS1 (rs13431179, rs16822615, 16822644rs, rs1801123) and TCF7L2 (rs7092484) tag SNPs were carries out using PCR-RFLP method of analysis. Haplotype analyses were carried out using Plink version 1.07, and Haploview 4.2 software. Linkage disequilibrium (LD), and Hardy-Weinberg equilibrium (HWE) analyses were performed using the Plink software. All descriptive statistical data analyses were carried out using SPSS (Version-20) software. Throughout the analysis p-value ≤0.05 was considered statistically significant. Result: Significant association was found between rs13431179 SNP of the IRS1 gene and T2DM under the recessive model of inheritance (OR=9.00, 95%CI=1.17-69.07, p=0.035), and marginally significant association found in the genotypic model (OR=7.50, 95%CI=0.94-60.06, p=0.058). The rs7092484 SNP of the TCF7L2 gene also showed markedly significant association with T2DM in the recessive (OR=3.61, 95%CI=1.70-7.67, p=0.001); and allelic (OR=1.80, 95%CI=1.23-2.62, p=0.002) models. Moreover, eight haplotypes of the IRS1 gene found to have significant association withT2DM (p=0.013 to 0.049). Assessments made on the interactions of genotypes of the rs13431179 and rs7092484 SNPs with various parameters demonstrated that high density lipoprotein (HDL), low density lipoprotein (LDL), waist circumference (WC), and systolic blood pressure (SBP) are the best T2DM onset predicting models. Furthermore, genotypes of the rs7092484 SNP showed significant association with various atherogenic indexes (Atherogenic index of plasma, LDL/HDL, and CHLO/HDL); and Eritreans carrying the GG or GA genotypes were predicted to be more susceptible to cardiovascular diseases onset. Conclusions: Results of this study suggest that IRS1 (rs13431179) and TCF7L2 (rs7092484) gene polymorphisms are associated with increased risk of T2DM in Eritreans.

Keywords: IRS1, SNP, TCF7L2, type 2 diabetes

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