Contribution of heavy bosons and fermions to the action for a Robertson-Walker metric.

The contributions of heavy, spatially homogeneous, boson and fermion fields to the effective action for a Robertson-Walker space-time are calculated. For scale factors larger than the Compton wavelengths of the particles associated with these matter fields the equations of motion for this scale factor are the same as those for a matter-dominated universe. Some speculations about the forces driving the expansion of the very early Universe are presented. © 1992 The American Physical Society

Genotype by Environment Interaction and Stability of Pod Yield of Elite Breeding Lines of Groundnut (Arachis hypogaea L.) in Eastern Ethiopia

Groundnut (Arachis hypogaea L.) yield under small scale farming of eastern Ethiopia is low (1.04 t ha-1) and highly variable over years and locations. Eleven elite breeding lines of groundnut were tested at Babile and Likale, eastern Ethiopia, in 2007, 2008 and 2009 to identify high yielding and stable genotypes. Additive main effect and multiplicative interaction (AMMI) model, cultivar-superiority measure, and genotype plus genotype by environment variation (GGE) were used to analyze multi-environment data. In the analysis of variance, all sources of variations showed statistically significant differences except year by genotype interaction indicating the possibilities for identification of best performing genotypes with specific and broad adaptability in the tested sites. AMMI analysis showed highly significant (P<0.01) effect of genotypes, environments and their interactions on dry pod yield. Similarly, the first and the second interaction principal component axis (IPCA 1 and IPCA 2) were highly significant (P<0.01) and explained 58.57 and 23.18 % of the G×E sum of squares, respectively. The environment had 84.7% effect, thereby explained high differences in genotype response to the tested environments. Genotype and genotype by environment interaction (GEI) accounted 6.6 and 8.7 %, respectively. Genotypes BaHa-jidu (-0.099), ICG-9251 (0.013), ICG-8644 (0.055) and Roba (0.057) with the lowest IPCA 1 showed the general adaptation in the mega-environment-1 (Ba2007, Ba2008 and Ba2009) and mega-environment-2 (Li2007, Li2008 and Li2009). BaHa-gudo had the highest mean dry pod yield (t ha-1) in a mega-environment-2 and highest PCA 1 score (0.343). Genotypes BaHa-jidu and BaHa-gudo had the smallest superiority measure values and had the highest dry pod yield and stability. In GGE bi-plot, PC 1 and PC 2 explained 51.2 and 30.6% of genotype by environment interaction, respectively. ICGV-8749 and BaHa-gudo were vertex genotypes at mega-environment-1 and mega-environment-2, respectively, whereas BaHa-jidu was vertex genotype in both mega-environments.Keywords: AMMI; GGE bi-plot; Groundnut; Mega-environment; Stability; Environment; Eastern Ethiopi

Natural occurrence and pathogenicity of Xanthomonas bacteria on selected plants

Peer Revie

Assessment of skin-to-skin contact (SSC) during the postpartum stay and its determinant factors among mothers at public health institutions in Ethiopia.

ObjectiveThe study aimed at assessing skin-to-skin contact (SSC) during the postpartum stay and its determinant factors among mothers at public health institutions in Ethiopia.ResultA total of 384 mothers-indexed newborns admitted in postnatal wards were interviewed. The prevalence of mothers' SSC practice to their newborns with in the first 1 h during the postpartum stay was 28.1%. Mothers education (AOR = 18.23 [95% CI 5.26, 63.52]), and number of ANC visits (AOR = 8.55 [95% CI 1.05, 69.54]) were independently associated with SSC practice of mothers to their infants

The Role of Current Emergency Radiology Practice: A prospective Cross-sectional Study Done at Tikur Anbessa Specialized Hospital

Background: The role of radiogy in the management of emergency  patients is tremendous. Which imaging modality best evaluates specific clinical emergencies has evolved and continues to advance with clinical practice trends. The purpose of this study was to show the role of radiology in emergency patient handeling and compare specific clinical entities with the standard.Methods: A prospective cross sectional study was done to describe the pattern of duty hour emergency utilization at Tikur Anbessa Hospital Department of Radiology. A total of 384 patient’s data were collected for the period of Jananuary 1st to April 30th 2010. The data which weredemographic variables, clinical diagnosis, radiologic diagnosis, type of investigation used, type of anatomic area imaged, whether primary investigation used or not, recommendations made by the radiology residents were collected and tabulated.Results: There were 242 (63%) males and 142 (37%) females. Suspected fracture was the commonest clinical indication for referring patients to the department of radiology at the duty hours and accounted for 40.9% of all cases. Otherclinical diagnoses included pnumonia (21.6%), blunt  abdominal trauma (5.7%) and pulmonary edema (4.7%). Plain  radiographs were taken in 88% of patients sent for imaging. Among the sonographic studies done, 43.4% were for patients presenting with blunt abdominal trauma. Of all patients in 90.4% primary investigative  modalities were used. Comparison of clinical and radiologic diagnosis was made in most common clinical cases and in general 51.3% of radiologic interpretations were normal.Conclusion: Plain radiography was used as the cornerstone investigative modality for emergency imaging. Fracture and pneumonia constituted the commonest indications for emergency imaging in all age groups. Over half of radiologic investigations were normal. It was observed that lack ofappropriate investigative modalities such as CT scan, doppler and high frequency ultrasonography greatly affected the quality of service the department offered and also negatively affected the training process.Key words: Emergency, Radiology, Practic

Structure and Regeneration Status of Gedo Dry Evergreen Montane Forest, West Shewa Zone of Oromia National Regional State, Central Ethiopia

This study was conducted on Gedo Dry Evergreen Montane Forest in West Shewa Zone of Oromia National Regional State, 182-196 km west of Addis Ababa (Finfinne). The objective of the study was to determine structure and regeneration status of Gedo Forest. All trees and shrubs with Diameter at Breast Height (DBH) ≥ 2 cm were measured for height and diameter. The density of tree species in Gedo Forest decreases with increasing height and DBH classes. The forest is characterized by high density of trees in the lower class than in the higher. Three layers (lower, middle and upper) of tree were identified from the study of vertical stratification of Gedo Forest following the International Union for Forestry Research Organization (IUFRO) classification scheme. The regeneration status of selected woody species was assessed as well as the forest was compared with five dry evergreen forests of Ethiopia. Based on the result of the study, research on the soil seed bank, population dynamics and ecology of endemic species were recommended.Keywords: Dry evergreen montane forest; Gedo Forest; Phytogeographical; Compariso

HIV self-testing practices among Health Care Workers: feasibility and options for accelerating HIV testing services in Ethiopia

Introduction: HIV is still an enormous global burden and it is also causing loss of huge health care workers (HCWs) on the already limited human resource capacity in health care services in Sub-Saharan Africa. Variety of methods of accelerating HIV testing is required to increase the rate of HIV testing and expand treatment services. Therefore, this study was aimed to find out the prevalence, feasibility and options of HIV self-testing practices in Ethiopia. Methods: A cross-sectional study design triangulated with qualitative method was conducted from February to May, 2012. The data was collected using a semi-structured pretested questionnaire and in-depth interview, at government and private health centers or clinics and hospitals. During the data collection all the available healthcare workers (HCWs) which encompass the internship students including: Medical, Health Officer, Nurses, Midwives and Laboratory students, and health professionals working in the selected health institutions were involved.Results: A total of 307 HCWs were included in the analysis and we found that 288(94.4%) of them were ever tested for HIV, of which majority 203 (70.5%) were tested by themselves though 244(80%) of the HCWs had motivation or interest to be tested by themselves. Generally, of the ever tested only 85(29.5%) were tested by the help of health care providers/counselors other than self. Regarding the place where the HCWs had the test, majority 136 (69.4%) tested by themselves at the health facility and the rest were tested at their home, office, market and church. The main reason stated for self-testing was the need for confidentiality for the test result, which was mentioned by 205(82%). Moreover, 35(14.0%) claims lack of time to access the ordinary counseling and testing services. Conclusion: This study depicts high rate of HIV self-testing practice among HCWs. This shows that HIV self-testing can be considered as one pillar to increase the HIV-testing services and a means for the HIV prevention and control policy, through increasing HIV testing uptake and awareness of HIV status. However, the implementation may require the role of different stakeholders and decision makers with further study to extend the options.Key words: HIV, VCT, self-test, health care workers, Ethiopi

Mothers' satisfaction with referral hospital delivery service in Amhara Region, Ethiopia

<p>Abstract</p> <p>Background</p> <p>A woman's satisfaction with the delivery service may have immediate and long-term effects on her health and subsequent utilization of the services. Providing satisfying delivery care increases service utilization. The objective of this study is to assess the satisfaction of mothers with referral hospitals' delivery service and identify some possible factors affecting satisfaction in Amhara region of Ethiopia.</p> <p>Methods</p> <p>A hospital-based cross-sectional survey that involved an exit interview was conducted from September to November 2009 in three referral hospitals in Ethiopia. A total of 417 delivering mothers were enrolled in the study. Client satisfaction was measured using a survey instrument adopted from the Donabedian quality assessment framework. We collect data systematically from every other postnatal woman who delivered in the referral hospitals. Multivariate and binary logistic regression was applied to identify the relative effect of each explanatory variable on the outcome (satisfaction).</p> <p>Results</p> <p>The proportion of mothers who were satisfied with delivery care in this study was 61.9%. Women's satisfaction with delivery care was associated with wanted status of the pregnancy, immediate maternal condition after delivery, waiting time to see the health worker, availability of waiting area, care providers' measure taken to assure privacy during examinations, and amount of cost paid for service.</p> <p>Conclusions</p> <p>The overall satisfaction of hospital delivery services in this study is found to be suboptimal. The study strongly suggests that more could be done to assure that services provided are more patient centered.</p

Synthesis and characterization of CdS/UiO-66/Ag3PO4 nanocomposite for photocatalytic degradation of methyl orange under visible light irradiation

Single, binary and ternary nanomaterials were synthesized by precipitation, solvothermal, simple solution and impregnation methods to serve as photocatalysts. The crystal structure, morphology, band gap energy, functional groups and optical properties of these materials were characterized by XRD, SEM-EDX, UV-Vis, FTIR, and PL instrumental techniques, respectively. Photocatalaytic degradation performances of all the as-synthesized photocatalysts were investigated under visible light irradiation using MO as a model organic pollutant. The photocatalytic degradation performances of all the photocatalysts were evaluated on aqueous solution of the model pollutant dye as well as on a real sewage sample solution collected from Bahir Dar Textile Share Company.&nbsp;Results suggested that the optimized ternary&nbsp;nanocomposite photocatalyst exhibited a relatively higher efficiency towards the photodegradation of both the methyl orange (MO) dye solution (90%) and the real sewage sample solution (71.2%). The effect of operational parameters such as pH (4), initial dye concentration (10 mg/L) and photocatalyst load (0.2 g/L) in MO dye degradation were investigated by using the ternary CdS/UiO-66/Ag3PO4 (R4) nanocomposite. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; KEY WORDS: Metal-organic frameworks, Nanocomposite, Ternary system, Photocatalysts, Methyl orange &nbsp; Bull. Chem. Soc. Ethiop. 2020, 34(3), 571-588. DOI: https://dx.doi.org/10.4314/bcse.v34i3.1

Photo-catalytic Removal of Methyl Orange Dye by Polyaniline Modified ZnO using Visible Radiation

Polyaniline modified zinc oxide (PANI/ZnO) nanocomposite was synthesized by in-situ polymerization process. The as-synthesized nano-ZnO, PANI and PANI/ZnO nanocomposite were characterized by X-ray diffraction (XRD), FT-IR, and UV-Vis spectroscopy. The UV–visible spectroscopy studies showed that the absorption peak for PANI/ZnO nanocomposite has a red shift toward visible wavelengths compared with the ZnO nanoparticles and PANI. Photocatalytic efficiency of PANI/ZnO nanocomposite was investigated for the degradation of methyl orange (MeO) dye as a model organic compound under Visible light irradiation. The photocatalytic activities of ZnO, PANI and PANI/ZnO nanocomposite were studied. The results showed that ZnO/PANI nanocomposite had greater photocatalytic activity than ZnO nanoparticles and PANI under visible light irradiation. According to these results, application of PANI as a shell on the surface of ZnO nanoparticles causes the enhanced photocatalytic activity of the PANI/ZnO nanocomposite. Influence of some operational parameters such as: amount of photocatalyst, pH of solution, and MeO dye initial concentration on the photodegradation reaction rate was investigated. The optimum values of pH and catalyst dose found to be 6 and 1.50 gmL-1 respectively. It was demonstrated that the photocatalytic degradation of MeO follows pseudo first-order kinetics. The PANI/ZnO nanocomposite photocatalysts have good photocatalytic stability and can be reused three times with only gradual loss of activity. Thus, the PANI/ZnO nanocomposites are efficient photocatalytic materials for degrading contaminated colored wastewater for reuse in textile industries under mild conditions.Keywords: PANI/ZnO Nanocomposite; Methyl orange; Visible light; photo-catalysis; Degradation rate constan